/*
Theme Name: Quiz Theme Modern
Version: 5.1 - Header Redesign + Wide Container
OPTIMIZED: Chỉ xóa :hover, giữ nguyên 100% code khác
*/

@import url('https://fonts.googleapis.com/css2?family=Nunito:wght@300;400;500;600;700;800&display=swap');

:root {
    --primary: #F97316;
    --primary-dark: #EA580C;
    --primary-light: #FB923C;
    --accent: #1e3a8a;
    --accent-dark: #1e40af;
    --success: #10B981;
    --purple: #8B5CF6;
    
    --text: #1F2937;
    --text-light: #6B7280;
    --text-muted: #9CA3AF;
    
    --bg: #FFFFFF;
    --bg-light: #FAFBFC;
    --bg-lighter: #F3F4F6;
    
    --border: #E5E7EB;
    --border-light: #F3F4F6;
    
    --shadow-sm: 0 1px 2px 0 rgba(0,0,0,0.03);
    --shadow: 0 4px 6px -1px rgba(0,0,0,0.06), 0 2px 4px -1px rgba(0,0,0,0.03);
    --shadow-md: 0 10px 15px -3px rgba(0,0,0,0.06), 0 4px 6px -2px rgba(0,0,0,0.03);
    --shadow-lg: 0 20px 25px -5px rgba(0,0,0,0.06), 0 10px 10px -5px rgba(0,0,0,0.02);
    --shadow-xl: 0 25px 50px -12px rgba(0,0,0,0.15);
    
    --radius-sm: 8px;
    --radius: 12px;
    --radius-md: 16px;
    --radius-lg: 20px;
    --radius-xl: 24px;
    
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Nunito', -apple-system, BlinkMacSystemFont, sans-serif;
    color: var(--text);
    line-height: 1.6;
    background: var(--bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: 1500px;
    margin: 0 auto;
    padding: 0 32px;
}

/* ========================================
   HEADER - NEW CLEAN DESIGN
======================================== */

.site-header {
    background: white;
    border-bottom: 1px solid #E5E7EB;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}

.header-container {
    max-width: 1500px;
    margin: 0 auto;
    padding: 0 32px;
    height: 100px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 60px;
}

.site-logo {
    flex-shrink: 0;
}

.site-logo a {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 900;
    font-size: 1.25rem;
}

.logo-text {
    font-size: 1.5rem;
    font-weight: 900;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
}

.header-nav {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.main-menu {
    display: flex;
    gap: 8px;
    list-style: none;
    margin: 0;
    padding: 0;
}

.main-menu > li {
    position: relative;
}

.main-menu > li > a {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 12px 20px;
    color: var(--text);
    font-weight: 800;
    font-size: 0.9375rem;
    border-radius: 10px;
    text-decoration: none;
    transition: var(--transition);
    white-space: nowrap;
}

.main-menu > li.current-menu-item > a,
.main-menu > li.current-menu-parent > a {
    background: linear-gradient(135deg, rgba(249,115,22,0.1) 0%, rgba(234,88,12,0.08) 100%);
    color: var(--primary);
    font-weight: 700;
}

.menu-item-has-children > a::after {
    content: '';
    display: inline-block;
    width: 6px;
    height: 6px;
    border-right: 2px solid currentColor;
    border-bottom: 2px solid currentColor;
    transform: rotate(45deg);
    margin-left: 4px;
    margin-top: -3px;
    opacity: 0.6;
    transition: var(--transition);
}

.sub-menu {
    display: none;
    position: absolute;
    top: calc(100% + 8px);
    left: 0;
    background: white;
    border-radius: 12px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.12);
    min-width: 220px;
    padding: 8px;
    margin: 0;
    list-style: none;
    border: 1px solid #E5E7EB;
    z-index: 1000;
}

.menu-item-has-children:hover > .sub-menu {
    display: block;
    animation: slideDown 0.25s ease;
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.sub-menu li {
    list-style: none;
    margin: 0;
}

.sub-menu li a {
    display: block;
    padding: 12px 16px;
    color: var(--text);
    font-weight: 600;
    font-size: 0.875rem;
    border-radius: 8px;
    text-decoration: none;
    transition: var(--transition);
}

.sub-menu li.current-menu-item a {
    background: linear-gradient(135deg, rgba(249,115,22,0.1) 0%, rgba(234,88,12,0.08) 100%);
    color: var(--primary);
    font-weight: 700;
}

.header-auth {
    display: flex;
    gap: 12px;
    align-items: center;
    flex-shrink: 0;
}

.btn-login {
    padding: 10px 20px;
    color: var(--text);
    font-weight: 600;
    font-size: 0.875rem;
    border-radius: 10px;
    text-decoration: none;
    transition: var(--transition);
}

.btn-register {
    padding: 12px 28px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    font-weight: 700;
    font-size: 0.875rem;
    border-radius: 10px;
    box-shadow: 0 2px 8px rgba(249, 115, 22, 0.25);
    text-decoration: none;
    transition: var(--transition);
    white-space: nowrap;
}

.mobile-menu-toggle {
    display: none;
    width: 44px;
    height: 44px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
    position: relative;
}

.mobile-menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text);
    margin: 5px auto;
    transition: var(--transition);
    border-radius: 2px;
}

/* ========================================
   HERO - Modern Gradient with Patterns
======================================== */

.hero-main {
    background: linear-gradient(135deg, #F97316 0%, #EA580C 50%, #DC2626 100%);
    padding: 80px 32px 100px;
    position: relative;
    overflow: hidden;
}

.hero-bg-pattern {
    position: absolute;
    inset: 0;
    background-image: 
        radial-gradient(circle at 15% 50%, rgba(255,255,255,0.25) 0%, transparent 25%),
        radial-gradient(circle at 85% 20%, rgba(255,255,255,0.22) 0%, transparent 25%),
        radial-gradient(circle at 70% 80%, rgba(255,255,255,0.2) 0%, transparent 30%);
    z-index: 1;
}

.hero-main::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -10%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(255,255,255,0.18) 0%, transparent 70%);
    border-radius: 50%;
    animation: pulse 4s ease-in-out infinite;
    z-index: 0;
}

.hero-main::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -5%;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(255,255,255,0.15) 0%, transparent 70%);
    border-radius: 50%;
    animation: pulse 5s ease-in-out infinite reverse;
    z-index: 0;
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
        opacity: 1;
    }
    50% {
        transform: scale(1.1);
        opacity: 0.8;
    }
}

.hero-layout {
    display: grid;
    grid-template-columns: 1.3fr 1fr;
    gap: 80px;
    align-items: center;
    max-width: 1500px;
    margin: 0 auto;
    position: relative;
    z-index: 2;
}

.hero-layout::before {
    content: '';
    position: absolute;
    top: 10%;
    right: 5%;
    width: 100px;
    height: 100px;
    background: rgba(255,255,255,0.12);
    border-radius: 30% 70% 70% 30% / 30% 30% 70% 70%;
    animation: morph 8s ease-in-out infinite;
    z-index: -1;
}

.hero-layout::after {
    content: '';
    position: absolute;
    bottom: 15%;
    left: 8%;
    width: 80px;
    height: 80px;
    background: rgba(255,255,255,0.14);
    border-radius: 63% 37% 54% 46% / 55% 48% 52% 45%;
    animation: morph 10s ease-in-out infinite reverse;
    z-index: -1;
}

@keyframes morph {
    0%, 100% {
        border-radius: 30% 70% 70% 30% / 30% 30% 70% 70%;
        transform: rotate(0deg);
    }
    50% {
        border-radius: 70% 30% 30% 70% / 70% 70% 30% 30%;
        transform: rotate(180deg);
    }
}

.hero-content {
    position: relative;
}

.hero-content::before,
.hero-content::after {
    content: '';
    position: absolute;
    border-radius: 50%;
    background: rgba(255,255,255,0.35);
}

.hero-content::before {
    width: 12px;
    height: 12px;
    top: 20%;
    left: -5%;
    animation: floatDot 3s ease-in-out infinite;
}

.hero-content::after {
    width: 8px;
    height: 8px;
    top: 60%;
    left: -2%;
    animation: floatDot 4s ease-in-out infinite 1s;
}

@keyframes floatDot {
    0%, 100% {
        transform: translateY(0) scale(1);
        opacity: 0.5;
    }
    50% {
        transform: translateY(-20px) scale(1.2);
        opacity: 0.8;
    }
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 900;
    color: white;
    margin: 0 0 24px 0;
    line-height: 1.1;
    letter-spacing: -0.03em;
    position: relative;
}

.hero-desc {
    font-size: 1.25rem;
    color: rgba(255,255,255,1);
    margin: 0 0 40px 0;
    line-height: 1.7;
    position: relative;
}

.hero-image {
    animation: float 6s ease-in-out infinite;
    position: relative;
}

.hero-image img {
    width: 100%;
    height: auto;
    filter: drop-shadow(0 20px 40px rgba(0,0,0,0.2)) brightness(1.05);
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-30px); }
}

/* ========================================
   SECTIONS
======================================== */

.grade-choose,
.quiz-latest,
.steps-section,
.stats-section,
.documents-section,
.feedback-section {
    padding: 100px 32px;
}

.grade-choose {
    background: linear-gradient(to bottom, #FAFBFC 0%, white 50%);
}

.quiz-latest {
    background: white;
}

.steps-section {
    background: #FAFBFC;
}

.stats-section {
    background: linear-gradient(135deg, #FFF7ED 0%, #FFEDD5 100%);
}

.documents-section {
    background: white;
}

.feedback-section {
    background: #FAFBFC;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 900;
    text-align: center;
    color: var(--primary);
    margin: 0 0 20px 0;
    letter-spacing: -0.03em;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 56px;
}

.section-header .section-title {
    margin: 0;
    text-align: left;
}

.section-link {
    color: var(--primary);
    font-weight: 700;
    font-size: 1rem;
    text-decoration: none;
    transition: var(--transition);
}

/* ========================================
   GRADE CARDS
======================================== */

.grade-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
    max-width: 1500px;
    margin: 0 auto;
}

.grade-card {
    background: white;
    border: 2px solid var(--border);
    border-radius: var(--radius-xl);
    padding: 36px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 32px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.grade-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 0;
    background: linear-gradient(to bottom, var(--primary), var(--primary-dark));
    transition: var(--transition);
}

.grade-card-content {
    flex: 1;
}

.grade-card h3 {
    font-size: 1.875rem;
    font-weight: 800;
    margin: 0 0 16px 0;
    color: #000000;
    letter-spacing: -0.02em;
}
.grade-card h3 a {
    color: #000000;
    text-decoration: none;
    transition: color 0.2s ease;
}

.grade-card h3 a:visited {
    color: #000000;
}

.grade-card h3 a:hover {
    color: #f97316; /* màu cam đồng bộ với nút Xem đề thi */
}

.grade-card p {
    color: #000000;
    font-size: 0.9375rem;
	font-weight: 700;
    margin: 0;
    line-height: 1.7;
}

.grade-card-btn {
    background: white;
    border: 2px solid var(--primary);
    color: var(--primary);
    padding: 14px 28px;
    border-radius: 50px;
    font-weight: 700;
    font-size: 0.9375rem;
    white-space: nowrap;
    text-decoration: none;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

/* ========================================
   QUIZ CARDS
======================================== */

.quiz-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
    max-width: 1500px;
    margin: 0 auto;
}

.quiz-card {
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 28px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    gap: 20px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.quiz-card-title a {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--text);
    text-decoration: none;
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    transition: var(--transition);
}

.quiz-card-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
}

.meta-item {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.875rem;
    color: var(--text-muted);
    font-weight: 500;
}

.meta-item svg {
    flex-shrink: 0;
    opacity: 0.7;
}

.quiz-card-btn {
    background: linear-gradient(135deg, var(--accent) 0%, var(--accent-dark) 100%);
    color: white;
    padding: 12px 24px;
    border-radius: var(--radius);
    font-weight: 700;
    font-size: 0.9375rem;
    text-decoration: none;
    text-align: center;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

/* ========================================
   STEPS
======================================== */

.steps-top {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
    margin-bottom: 80px;
    max-width: 1500px;
    margin-left: auto;
    margin-right: auto;
}

.step-card {
    background: white;
    border: 2px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 36px 28px;
    transition: var(--transition);
}

.step-num {
    color: var(--accent);
    font-weight: 800;
    font-size: 1.125rem;
    margin-bottom: 16px;
    display: inline-block;
    padding: 4px 12px;
    background: rgba(249,115,22,0.1);
    border-radius: var(--radius-sm);
}

.step-card h3 {
    font-size: 1.375rem;
    font-weight: 800;
    margin: 0 0 16px 0;
    color: #f97316;
}

.step-card p {
    color: #000000;
    font-size: 0.9375rem;
	font-weight: 700;
    line-height: 1.7;
    margin: 0;
}

.steps-bottom {
    display: grid;
    grid-template-columns: 420px 1fr;
    gap: 80px;
    align-items: center;
    max-width: 1500px;
    margin: 0 auto;
}

.steps-image img {
    width: 100%;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
}

.steps-features {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 28px;
}

.feature-item {
    display: flex;
    gap: 16px;
    align-items: flex-start;
}

.feature-icon {
    width: 52px;
    height: 52px;
    background: linear-gradient(135deg, #FFF7ED 0%, #FFEDD5 100%);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    flex-shrink: 0;
    box-shadow: var(--shadow-sm);
}

.feature-item h4 {
    font-size: 1.0625rem;
    font-weight: 800;
    margin: 0 0 8px 0;
    color: var(--text);
}

.feature-item p {
    color: #000000;
    font-size: 0.875rem;
	font-weight: 700;
    line-height: 1.6;
    margin: 0;
}

/* ========================================
   STATS
======================================== */

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 28px;
    max-width: 1500px;
    margin: 0 auto;
}

.stat-box {
    background: white;
    border-radius: var(--radius-lg);
    padding: 40px 28px;
    text-align: center;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.stat-icon {
    font-size: 2.5rem;
    margin-bottom: 20px;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 900;
    color: var(--primary);
    margin-bottom: 12px;
    letter-spacing: -0.02em;
}

.stat-label {
    color: #000000;
    font-weight: 700;
    font-size: 1rem;
}

/* ========================================
   DOCUMENTS
======================================== */

.doc-layout {
    display: grid;
    grid-template-columns: 1fr 440px;
    gap: 80px;
    align-items: center;
    max-width: 1500px;
    margin: 0 auto;
}

.doc-list {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.doc-item {
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px;
    display: flex;
    align-items: center;
    gap: 16px;
    transition: var(--transition);
}

.doc-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, #FFF7ED 0%, #FFEDD5 100%);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    flex-shrink: 0;
}

.doc-item span {
    font-size: 0.9375rem;
    color: #000000;
    font-weight: 700;
    line-height: 1.5;
}

.doc-image img {
    width: 100%;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
}

/* ========================================
   FEEDBACK
======================================== */

.feedback-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
    max-width: 1500px;
    margin: 0 auto;
}

.feedback-card {
    background: white;
    border: 2px solid var(--border);
    border-radius: var(--radius-xl);
    padding: 40px 32px;
    text-align: center;
    position: relative;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.feedback-quote {
    position: absolute;
    top: 24px;
    right: 24px;
    font-size: 2rem;
    color: var(--primary);
    opacity: 0.8;
}

.feedback-avatar {
    width: 88px;
    height: 88px;
    margin: 0 auto 20px;
    border-radius: 50%;
    overflow: hidden;
    border: 4px solid #FFF7ED;
    box-shadow: var(--shadow);
}

.feedback-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.feedback-card h4 {
    font-size: 1.125rem;
    font-weight: 700;
    margin: 0 0 10px 0;
    color: #1e3a8a;
}

.feedback-stars {
    color: #FCD34D;
    margin-bottom: 20px;
    font-size: 1.25rem;
}

.feedback-card p {
    color: #000000;
    font-size: 0.9375rem;
	font-weight: 700;
    line-height: 1.7;
    margin: 0;
	text-align: justify;
}

/* ========================================
   FOOTER
======================================== */

.site-footer {
    background: linear-gradient(135deg, #374151 0%, #1F2937 100%);
    color: #D1D5DB;
    padding: 80px 32px 32px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr repeat(3, 1fr);
    gap: 60px;
    max-width: 1500px;
    margin: 0 auto 48px;
}

.footer-title {
    color: white;
    font-size: 1.375rem;
    font-weight: 800;
    margin-bottom: 20px;
}

.footer-desc {
    line-height: 1.7;
    margin-bottom: 24px;
}

.footer-social {
    display: flex;
    gap: 12px;
}

.social-link {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255,255,255,0.1);
    border-radius: var(--radius);
    transition: var(--transition);
}

.footer-heading {
    color: white;
    font-size: 1.0625rem;
    font-weight: 700;
    margin-bottom: 20px;
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 14px;
}

.footer-links a {
    color: #D1D5DB;
    text-decoration: none;
    transition: var(--transition);
}

.footer-bottom {
    background: rgba(0,0,0,0.2);
    padding: 28px 0;
    margin-top: 48px;
}

.footer-bottom-inner {
    max-width: 1500px;
    margin: 0 auto;
    padding: 0 32px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.copyright {
    color: #9CA3AF;
    margin: 0;
}

.footer-bottom-links {
    display: flex;
    gap: 20px;
    align-items: center;
}

.footer-bottom-links a {
    color: #D1D5DB;
    text-decoration: none;
}

.footer-bottom-links .divider {
    color: #6B7280;
}

/* ========================================
   RESPONSIVE - BASE
======================================== */

@media (max-width: 1024px) {
    .container {
        padding: 0 32px;
    }
    
    .header-container {
        padding: 0 32px;
        gap: 40px;
    }
    
    .main-menu {
        gap: 4px;
    }
    
    .main-menu > li > a {
        padding: 10px 16px;
        font-size: 0.875rem;
    }
    
    .quiz-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .steps-features {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .header-container {
        height: 70px;
        padding: 0 20px;
    }
    
    .logo-text {
        font-size: 1.25rem;
    }
    
    .logo-icon {
        width: 36px;
        height: 36px;
        font-size: 1.125rem;
    }
    
    .mobile-menu-toggle {
        display: block;
    }
    
    .header-nav {
        display: none;
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: white;
        border-bottom: 1px solid #E5E7EB;
        box-shadow: 0 4px 12px rgba(0,0,0,0.1);
        padding: 20px;
        z-index: 999;
        max-height: calc(100vh - 70px);
        overflow-y: auto;
    }
    
    .header-nav.active {
        display: block;
    }
    
    .main-menu {
        flex-direction: column;
        gap: 8px;
    }
    
    .main-menu > li > a {
        width: 100%;
        justify-content: space-between;
    }
    
    .sub-menu {
        position: static;
        box-shadow: none;
        border: none;
        background: var(--bg-light);
        margin-top: 8px;
    }
    
    .menu-item-has-children .sub-menu {
        display: none;
    }
    
    .menu-item-has-children.active .sub-menu {
        display: block;
    }
    
    .header-auth {
        flex-direction: column;
        width: 100%;
        margin-top: 16px;
        padding-top: 16px;
        border-top: 1px solid #E5E7EB;
    }
    
    .btn-login,
    .btn-register {
        width: 100%;
        text-align: center;
        justify-content: center;
        display: block;
    }
    
    .hero-title {
        font-size: 2.25rem;
    }
    
    .hero-layout,
    .steps-bottom,
    .doc-layout {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .hero-image {
        order: -1;
    }
    
    .grade-grid,
    .quiz-grid,
    .steps-top,
    .stats-grid,
    .doc-list,
    .feedback-grid,
    .footer-grid {
        grid-template-columns: 1fr;
    }
    
    .grade-card {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .grade-card-btn {
        width: 100%;
        justify-content: center;
    }
    
    .section-header {
        flex-direction: column;
        gap: 16px;
        align-items: flex-start;
    }
}
/* ========================================
   TIẾP TỤC TỪ PART 1
   HOMEPAGE ONLY - Copy nguyên code gốc
======================================== */

/* Hero Layout */
.hero-main .hero-layout {
    grid-template-columns: 1.2fr 1fr !important;
    gap: 60px !important;
}

.hero-main .hero-image img {
    max-width: 500px;
    object-fit: contain;
}

.hero-main .search-box {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.hero-main .search-form-wrapper {
    display: flex;
    align-items: center;
    gap: 0;
    background: white;
    border-radius: 16px;
    padding: 8px 8px 8px 24px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.15);
}

.hero-main .search-icon {
    color: var(--text-muted);
    flex-shrink: 0;
    margin-right: 12px;
}

.hero-main .search-field {
    flex: 1;
    border: none;
    outline: none;
    padding: 12px 0;
    font-size: 1rem;
    color: var(--text);
    background: transparent;
}

.hero-main .search-field::placeholder {
    color: var(--text-muted);
}

.hero-main .btn-search-inline {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    border: none;
    border-radius: 12px;
    font-weight: 700;
    font-size: 0.9375rem;
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
    flex-shrink: 0;
}

.hero-main .btn-search-inline svg {
    width: 18px;
    height: 18px;
}

.hero-main .hero-actions {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.hero-main .btn-search-primary,
.hero-main .btn-search-outline {
    flex: 1;
    min-width: 180px;
    padding: 14px 32px;
    border-radius: 50px;
    font-weight: 700;
    font-size: 0.9375rem;
    cursor: pointer;
    border: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: var(--transition);
    white-space: nowrap;
    text-decoration: none;
}

.hero-main .btn-search-primary {
    background: linear-gradient(135deg, var(--accent) 0%, var(--accent-dark) 100%);
    color: white;
    box-shadow: 0 4px 12px rgba(30, 58, 138, 0.4);
}

.hero-main .btn-search-outline {
    background: rgba(255,255,255,0.2);
    backdrop-filter: blur(10px);
    color: white;
    border: 2px solid rgba(255,255,255,0.4);
}

/* ========================================
   STEPS SECTION
======================================== */

.steps-section .steps-bottom {
    grid-template-columns: 400px 1fr !important;
    gap: 60px !important;
}

.steps-section .steps-image img {
    max-width: 420px;
    box-shadow: 0 20px 50px rgba(0,0,0,0.15);
    object-fit: cover;
}

.steps-section .steps-features {
    grid-template-columns: 1fr !important;
    gap: 24px;
}

.steps-section .feature-item {
    background: white;
    padding: 24px;
    border: 2px solid var(--border-light);
    border-radius: var(--radius);
}

.steps-section .feature-icon {
    width: 64px !important;
    height: 64px !important;
    padding: 8px;
    box-shadow: 0 4px 12px rgba(249, 115, 22, 0.1);
}

.steps-section .feature-icon img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

/* ========================================
   STATS SECTION
======================================== */

.stats-section {
    padding: 80px 32px !important;
}

.stats-section .stats-grid {
    gap: 32px !important;
}

.stats-section .stat-box {
    padding: 36px 24px;
    border: 2px solid transparent;
}

.stats-section .stat-icon {
    filter: drop-shadow(0 4px 8px rgba(0,0,0,0.1));
    transition: var(--transition);
}

.stats-section .stat-icon img {
    width: 72px;
    height: 72px;
    object-fit: contain;
}

/* ========================================
   DOCUMENTS SECTION
======================================== */

.documents-section .doc-layout {
    grid-template-columns: 1fr 400px !important;
    gap: 60px;
}

.documents-section .doc-list {
    grid-template-columns: 1fr !important;
    gap: 16px;
}

.documents-section .doc-item {
    border: 2px solid var(--border);
}

.documents-section .doc-icon {
    width: 52px;
    height: 52px;
    box-shadow: 0 2px 8px rgba(249, 115, 22, 0.1);
}

.documents-section .doc-image img {
    max-width: 440px;
    box-shadow: 0 20px 50px rgba(0,0,0,0.12);
    object-fit: cover;
}

/* ========================================
   FEEDBACK SECTION
======================================== */

.feedback-section {
    padding: 100px 32px !important;
}

.feedback-section .feedback-grid {
    gap: 28px;
}

.feedback-section .feedback-card {
    padding: 40px 28px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.04);
}

.feedback-section .feedback-quote {
    width: 40px !important;
    height: 40px !important;
    opacity: 0.2;
}

.feedback-section .feedback-quote img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.feedback-section .feedback-avatar {
    width: 96px !important;
    height: 96px !important;
    margin: 0 auto 24px;
    box-shadow: 0 8px 20px rgba(0,0,0,0.12);
}

.feedback-section .feedback-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.feedback-section .feedback-card h4 {
    font-size: 1.125rem;
    font-weight: 800;
    margin: 0 0 12px 0;
}

.feedback-section .feedback-card p {
    font-size: 0.9375rem;
    line-height: 1.8;
}

/* ========================================
   RESPONSIVE - HOMEPAGE ONLY
======================================== */

@media (max-width: 1200px) {
    .hero-main .hero-layout,
    .steps-section .steps-bottom,
    .documents-section .doc-layout {
        gap: 48px !important;
    }
}

@media (max-width: 1024px) {
    .hero-main .hero-layout,
    .steps-section .steps-bottom,
    .documents-section .doc-layout {
        grid-template-columns: 1fr !important;
        gap: 40px !important;
    }
    
    .hero-main .hero-image,
    .steps-section .steps-image,
    .documents-section .doc-image {
        order: -1;
        text-align: center;
    }
    
    .steps-section .steps-image img,
    .documents-section .doc-image img {
        max-width: 360px;
    }
    
    .stats-section .stats-grid {
        grid-template-columns: repeat(2, 1fr) !important;
        gap: 24px !important;
    }
}

@media (max-width: 768px) {
    .hero-main .search-box {
        gap: 12px;
    }
    
    .hero-main .search-form-wrapper {
        padding: 6px 6px 6px 16px;
    }
    
    .hero-main .search-field {
        font-size: 0.9375rem;
        padding: 10px 0;
    }
    
    .hero-main .btn-search-inline {
        padding: 10px 20px;
        font-size: 0.875rem;
    }
    
    .hero-main .btn-search-inline svg {
        width: 16px;
        height: 16px;
    }
    
    .hero-main .hero-actions {
        flex-direction: column;
        width: 100%;
    }
    
    .hero-main .btn-search-primary,
    .hero-main .btn-search-outline {
        width: 100%;
        min-width: auto;
    }
    
    .hero-main .hero-image img {
        max-width: 340px;
    }
    
    .steps-section .steps-image img {
        max-width: 300px;
    }
    
    .documents-section .doc-image img {
        max-width: 300px;
    }
    
    .steps-section .feature-icon {
        width: 52px !important;
        height: 52px !important;
    }
    
    .stats-section .stat-icon img {
        width: 60px !important;
        height: 60px !important;
    }
    
    .feedback-section .feedback-avatar {
        width: 80px !important;
        height: 80px !important;
    }
    
    .feedback-section .feedback-quote {
        width: 32px !important;
        height: 32px !important;
    }
    
    .steps-section .feature-item,
    .documents-section .doc-item {
        padding: 16px;
    }
    
    .stats-section .stat-box {
        padding: 28px 20px;
    }
    
    .feedback-section .feedback-card {
        padding: 32px 24px;
    }
}

@media (max-width: 480px) {
    .hero-main .btn-search-inline span {
        display: none;
    }
    
    .hero-main .btn-search-inline {
        padding: 10px 16px;
    }
}

/* ========================================
   GRADE PAGE - REDESIGN THU HÚT
   CHỈ COPY PHẦN NÀY VÀO STYLE.CSS
======================================== */

.grade-page .breadcrumb-section {
    background: white;
    padding: 16px 0;
    border-bottom: 1px solid var(--border);
}

.grade-page .page-header {
    background: linear-gradient(135deg, #2563EB 0%, #1E40AF 100%);
    padding: 60px 32px;
    position: relative;
    overflow: hidden;
}

.grade-page .page-header::before {
    content: '';
    position: absolute;
    inset: 0;
    background: 
        linear-gradient(135deg, #1E40AF 0%, #1E3A8A 100%);
    pointer-events: none;
}

.grade-page .page-header::after {
    content: '';
    position: absolute;
    bottom: -50px;
    right: -50px;
    width: 300px;
    height: 300px;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.grade-page .page-header .container {
    max-width: 1500px;
    margin: 0 auto;
    position: relative;
    text-align: left;
    z-index: 2;
}

.grade-page .page-title {
    font-size: 2.75rem;
    font-weight: 900;
    color: white;
    margin: 0;
    letter-spacing: -0.02em;
    position: relative;
    text-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.grade-page .page-subtitle {
    font-size: 1.25rem;
    color: rgba(255, 255, 255, 0.95);
    margin: 0;
    position: relative;
    font-weight: 500;
}

.grade-page .courses-grid-section {
    padding: 80px 32px 100px;
    background: linear-gradient(to bottom, #F9FAFB 0%, white 100%);
}

.grade-page .courses-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 28px;
    max-width: 1500px;
    margin: 0 auto;
}

.grade-page .course-card {
    background: white;
    border: 2px solid #E5E7EB;
    border-radius: 20px;
    padding: 40px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
    cursor: pointer;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}

.grade-page .course-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 6px;
    height: 0;
    background: linear-gradient(to bottom, #F97316, #EA580C);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.grade-page .course-card::after {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at center, rgba(249,115,22,0.03) 0%, transparent 70%);
    opacity: 0;
    transition: all 0.5s ease;
    pointer-events: none;
}

.grade-page .course-card-title {
    font-size: 1.625rem;
    font-weight: 800;
    color: #111827;
    margin: 0 0 24px 0;
    letter-spacing: -0.02em;
    line-height: 1.3;
    transition: all 0.3s;
    position: relative;
    z-index: 2;
}

.grade-page .course-card-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    width: 100%;
    padding: 16px 32px;
    background: linear-gradient(135deg, #F97316 0%, #EA580C 100%);
    color: white;
    font-size: 1.0625rem;
    font-weight: 700;
    text-decoration: none;
    border-radius: 12px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 4px 12px rgba(249, 115, 22, 0.25);
    position: relative;
    overflow: hidden;
    z-index: 2;
}

.grade-page .course-card-link::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(255,255,255,0.2) 0%, transparent 100%);
    opacity: 0;
    transition: opacity 0.3s;
}

.grade-page .course-card-link::after {
    content: '→';
    font-size: 1.25rem;
    transition: transform 0.3s;
}

/* ========================================
   RESPONSIVE - GRADE PAGE
======================================== */

@media (max-width: 768px) {
    .grade-page .page-header {
        padding: 48px 16px !important;
    }
    
    .grade-page .page-title {
        font-size: 2rem !important;
    }
    
    .grade-page .page-subtitle {
        font-size: 1rem !important;
    }
    
    .grade-page .courses-grid-section {
        padding: 60px 16px 80px !important;
    }
    
    .grade-page .courses-grid {
        grid-template-columns: 1fr !important;
        gap: 20px;
    }
    
    .grade-page .course-card {
        padding: 32px 24px !important;
    }
    
    .grade-page .course-card-title {
        font-size: 1.375rem !important;
        margin-bottom: 20px !important;
    }
    
    .grade-page .course-card-link {
        padding: 14px 28px !important;
        font-size: 1rem !important;
    }
}

@media (max-width: 480px) {
    .grade-page .page-header {
        padding: 40px 12px !important;
    }
    
    .grade-page .page-title {
        font-size: 1.75rem !important;
    }
    
    .grade-page .page-subtitle {
        font-size: 0.9375rem !important;
    }
    
    .grade-page .courses-grid-section {
        padding: 50px 12px 70px !important;
    }
    
    .grade-page .course-card {
        padding: 28px 20px !important;
        border-radius: 16px;
    }
    
    .grade-page .course-card-title {
        font-size: 1.25rem !important;
    }
    
    .grade-page .course-card-link {
        padding: 12px 24px !important;
        font-size: 0.9375rem !important;
    }
}

/* ========================================
   COURSE PAGE
======================================== */

.course-page .breadcrumb-section {
    background: white;
    padding: 16px 0;
    border-bottom: 1px solid var(--border);
}

.course-page .subject-tabs-section {
    background: white;
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 80px;
    z-index: 100;
    box-shadow: 0 2px 4px rgba(0,0,0,0.02);
    overflow: hidden; /* Quan trọng */
}

.course-page .subject-tabs-scroll {
    overflow-x: auto !important; /* Cho phép scroll ngang */
    overflow-y: hidden;
    -webkit-overflow-scrolling: touch; /* Smooth scroll trên iOS */
    scrollbar-width: thin; /* Firefox */
    scrollbar-color: #9E9E9E #FF9800; /* Firefox */
}

.course-page .subject-tabs-scroll::-webkit-scrollbar {
    height: 6px; /* Chiều cao scrollbar */
    display: block !important; /* Hiển thị scrollbar */
}

.course-page .subject-tabs-scroll::-webkit-scrollbar-track {
    background: #F3F4F6;
    border-radius: 3px;
}

.course-page .subject-tabs-scroll::-webkit-scrollbar-thumb {
    background: #E5E7EB;
    border-radius: 3px;
    transition: background 0.3s;
}

.course-page .subject-tabs-scroll::-webkit-scrollbar-thumb:hover {
    background: #D1D5DB;
}

.course-page .subject-tabs {
    display: flex;
    gap: 4px;
    padding: 16px 32px;
    min-width: min-content; /* Quan trọng - cho phép mở rộng */
    max-width: none !important; /* Bỏ giới hạn max-width */
    margin: 0;
    width: max-content; /* Tự động điều chỉnh width */
}

.course-page .subject-tab {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    padding: 16px 24px;
    border-radius: var(--radius-md);
    text-decoration: none;
    transition: var(--transition);
    background: transparent;
    border: 2px solid transparent;
    min-width: 110px; /* Đảm bảo không bị co lại */
    flex-shrink: 0; /* Quan trọng - không cho phép thu nhỏ */
    position: relative;
}

.course-page .subject-tab::after {
    content: '';
    position: absolute;
    bottom: -16px;
    left: 50%;
    transform: translateX(-50%) scaleX(0);
    width: 80%;
    height: 3px;
    background: var(--primary);
    transition: var(--transition);
    border-radius: 2px 2px 0 0;
}

.course-page .subject-tab.active {
    background: linear-gradient(135deg, rgba(249,115,22,0.05) 0%, rgba(234,88,12,0.05) 100%);
}

.course-page .subject-tab.active::after {
    transform: translateX(-50%) scaleX(1);
}

.course-page .tab-icon {
    width: 56px;
    height: 56px;
    background-size: contain;
    background-position: center;
    background-repeat: no-repeat;
    transition: var(--transition);
    filter: grayscale(0.3);
    flex-shrink: 0;
}
.course-page .subject-tab.active .tab-icon {
    filter: grayscale(0);
}

.course-page .tab-name {
    font-size: 0.875rem;
    font-weight: 700;
    color: var(--text-light);
    text-align: center;
    line-height: 1.3;
    transition: var(--transition);
    white-space: nowrap; /* Không cho xuống dòng */
}

.course-page .subject-tab.active .tab-name {
    color: var(--primary);
}

.course-page .subject-tabs-section::before,
.course-page .subject-tabs-section::after {
    content: '';
    position: absolute;
    top: 0;
    bottom: 6px; /* Trừ chiều cao scrollbar */
    width: 40px;
    pointer-events: none;
    z-index: 10;
    opacity: 0;
    transition: opacity 0.3s;
}

.course-page .subject-tabs-section::before {
    left: 0;
    background: linear-gradient(to right, white, transparent);
}

.course-page .subject-tabs-section::after {
    right: 0;
    background: linear-gradient(to left, white, transparent);
}

/* Hiển thị fade khi scroll (cần JS, nhưng có thể bỏ) */
.course-page .subject-tabs-section.has-scroll::before,
.course-page .subject-tabs-section.has-scroll::after {
    opacity: 1;
}

.course-page .course-header {
    position: relative;
    padding: 40px 32px;
    background: linear-gradient(135deg, #1E40AF 0%, #1E3A8A 100%);
    overflow: hidden;
}

.course-page .course-header-bg {
    position: absolute;
    inset: 0;
    background-image: 
        radial-gradient(circle at 15% 50%, rgba(255,255,255,0.15) 0%, transparent 30%),
        radial-gradient(circle at 85% 20%, rgba(255,255,255,0.12) 0%, transparent 30%);
    pointer-events: none;
}

.course-page .course-header-content {
    max-width: 1500px;
    margin: 0 auto;
    position: relative;
    z-index: 2;
}

.course-page .course-title {
    font-size: 2rem;
    font-weight: 800;
    color: white;
    margin: 0;
    letter-spacing: -0.02em;
    line-height: 1.2;
}

.course-page .chapters-section {
    padding: 60px 32px;
    background: #FAFBFC;
}

.course-page .chapters-section .container {
    max-width: 1500px;
    margin: 0 auto;
}

.course-page .chapter-section {
    margin-bottom: 60px;
}

.course-page .chapter-section-title {
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--accent);
    margin: 0 0 28px 0;
    text-transform: uppercase;
    letter-spacing: 0.02em;
    display: flex;
    align-items: center;
    gap: 12px;
}

.course-page .chapter-bar {
    width: 4px;
    height: 28px;
    background: var(--primary);
    border-radius: 2px;
    flex-shrink: 0;
}

.course-page .lessons-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

.course-page .lesson-box {
    background: white;
    border: 1px solid #E5E7EB;
    border-radius: var(--radius);
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    transition: var(--transition);
}

.course-page .lesson-box-title {
    font-size: 0.9375rem;
    font-weight: 700;
    color: var(--text);
    margin: 0;
    line-height: 1.5;
    min-height: 48px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.course-page .lesson-box-title a,
.course-page .lesson-box-title-link {
	font-weight: 700;
    color: #000000;
    text-decoration: none;
    transition: var(--transition);
}

.course-page .lesson-box-meta {
    display: flex;
    gap: 16px;
    padding: 12px 0;
    border-top: 1px solid #F3F4F6;
    border-bottom: 1px solid #F3F4F6;
}

.course-page .meta-icon-item {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.8125rem;
    color: #6B7280;
    font-weight: 700;
}

.course-page .lesson-box-btn {
    background: var(--primary);
    color: white;
    padding: 10px 20px;
    border-radius: 6px;
    font-size: 0.875rem;
    font-weight: 700;
    text-align: center;
    text-decoration: none;
    transition: var(--transition);
    display: block;
}

/* ========================================
   LESSON PAGE
======================================== */

.lesson-page .breadcrumb-section {
    background: white;
    padding: 16px 0;
    border-bottom: 1px solid var(--border);
}

.lesson-page .lesson-header {
    background: linear-gradient(135deg, var(--accent) 0%, var(--accent-dark) 100%);
    padding: 40px 32px;
    position: relative;
    overflow: hidden;
}

.lesson-page .lesson-header::before {
    content: '';
    position: absolute;
    inset: 0;
    background: 
        radial-gradient(circle at 25% 50%, rgba(255,255,255,0.1) 0%, transparent 50%),
        radial-gradient(circle at 75% 60%, rgba(255,255,255,0.08) 0%, transparent 50%);
}

.lesson-page .lesson-page-title {
    font-size: 1.875rem;
    font-weight: 900;
    color: white;
    margin: 0;
    letter-spacing: -0.02em;
    position: relative;
    max-width: 1500px;
    margin-left: auto;
    margin-right: auto;
}

.lesson-page .lesson-main-content {
    display: grid;
    grid-template-columns: 500px 1fr;
    gap: 32px;
    max-width: 1500px;
    margin: 0 auto;
    padding: 60px 32px;
    background: var(--bg-light);
}

.lesson-page .theory-section {
    grid-column: 1;
    grid-row: 1;
}

.lesson-page .lessons-section {
    grid-column: 2;
    grid-row: 1;
}

.lesson-page .current-quizzes-section {
    grid-column: 1 / -1;
    grid-row: 2;
    padding: 60px 0;
    background: white;
}

.lesson-page .preview-section {
    grid-column: 1 / -1;
    grid-row: 3;
    padding: 60px 0;
    background: white;
}

.lesson-page .theory-column {
    position: sticky;
    top: 90px;
}

.lesson-page .theory-box {
    background: white;
    border: 2px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.lesson-page .theory-header {
    background: linear-gradient(135deg, #EFF6FF 0%, #DBEAFE 100%);
    padding: 20px 24px;
    display: flex;
    align-items: center;
    gap: 12px;
    border-bottom: 2px solid var(--border-light);
}

.lesson-page .theory-header h2 {
    font-size: 1.125rem;
    font-weight: 800;
    color: var(--accent);
    margin: 0;
}

.lesson-page .theory-title {
    padding: 24px 24px 20px 24px;
    border-bottom: 2px solid var(--border-light);
}

.lesson-page .theory-title h3 {
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--text);
    margin: 0 0 8px 0;
    line-height: 1.4;
}

.lesson-page .theory-title .course-name {
    font-size: 0.875rem;
    color: var(--primary);
    font-weight: 600;
    margin: 0;
}

.lesson-page .theory-content {
    padding: 24px;
    color: var(--text);
    line-height: 1.8;
	text-align: justify;
}

.lesson-page .theory-content p {
    margin: 0 0 16px 0;
}

.lesson-page .theory-content p:last-child {
    margin-bottom: 0;
}

.lesson-page .theory-content ul,
.lesson-page .theory-content ol {
    margin: 0 0 16px 0;
    padding-left: 24px;
}

.lesson-page .theory-content li {
    margin-bottom: 8px;
}

.lesson-page .theory-content h2,
.lesson-page .theory-content h3,
.lesson-page .theory-content h4 {
    color: var(--text);
    font-weight: 700;
    margin: 24px 0 12px 0;
}

.lesson-page .theory-content strong {
    color: var(--primary);
    font-weight: 700;
}

.lesson-page .lessons-box {
    background: white;
    border: 2px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.lesson-page .lessons-header {
    background: linear-gradient(135deg, #FFF7ED 0%, #FFEDD5 100%);
    padding: 20px 24px;
    display: flex;
    align-items: center;
    gap: 12px;
    border-bottom: 2px solid var(--border-light);
}

.lesson-page .lessons-header h2 {
    font-size: 1.125rem;
    font-weight: 800;
    color: var(--primary);
    margin: 0;
}

.lesson-page .lessons-list-box {
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.lesson-page .lesson-item-card {
    background: #FAFBFC;
    border: 2px solid var(--border);
    border-radius: var(--radius);
    padding: 16px 20px;
    display: flex;
    align-items: center;
    gap: 16px;
    transition: var(--transition);
}

.lesson-page .lesson-number {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.125rem;
    font-weight: 800;
    flex-shrink: 0;
}

.lesson-page .lesson-info {
    flex: 1;
}

.lesson-page .lesson-card-title {
    font-size: 1rem;
    font-weight: 700;
    margin: 0 0 8px 0;
}

.lesson-page .lesson-card-title a {
    color: var(--text);
    text-decoration: none;
    transition: var(--transition);
}

.lesson-page .lesson-meta-row {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.lesson-page .meta-item-small {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: 0.8125rem;
    color: var(--text-muted);
    font-weight: 600;
}

.lesson-page .current-quizzes-section .container {
    max-width: 1500px;
    margin: 0 auto;
    padding: 0 32px;
}

.lesson-page .section-heading {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text);
    margin: 0 0 28px 0;
    display: flex;
    align-items: center;
    gap: 12px;
}

.lesson-page .current-quizzes-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.lesson-page .quiz-card-item {
    background: white;
    border: 2px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    transition: var(--transition);
}

.lesson-page .difficulty-badge {
    display: inline-block;
    padding: 6px 14px;
    border-radius: 50px;
    font-size: 0.75rem;
    font-weight: 700;
}

.lesson-page .difficulty-easy {
    background: #D1FAE5;
    color: #059669;
}

.lesson-page .difficulty-medium {
    background: #FEF3C7;
    color: #D97706;
}

.lesson-page .difficulty-hard {
    background: #FED7AA;
    color: #EA580C;
}

.lesson-page .difficulty-very-hard {
    background: #FEE2E2;
    color: #DC2626;
}

.lesson-page .preview-section .container {
    max-width: 1500px;
    margin: 0 auto;
    padding: 0 32px;
}

.lesson-page .questions-container {
    background: white;
    border: 2px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.lesson-page .question-item {
    padding: 20px 24px;
}

.lesson-page .question-num {
    display: inline-block;
    background: var(--primary);
    color: white;
    padding: 4px 12px;
    border-radius: 50px;
    font-size: 0.8125rem;
    font-weight: 700;
}

.lesson-page .question-text {
    font-size: 0.9375rem;
    font-weight: 600;
    color: var(--text);
    line-height: 1.6;
    margin-top: 8px;
	text-align: justify;
}

.lesson-page .question-options,
.lesson-page .question-statements {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.lesson-page .question-option,
.lesson-page .question-statement {
    background: var(--bg-light);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 10px 12px;
    display: flex;
    gap: 10px;
}

.lesson-page .opt-key,
.lesson-page .stmt-key {
    font-weight: 700;
    color: var(--accent);
    flex-shrink: 0;
    min-width: 20px;
}

.lesson-page .opt-text,
.lesson-page .stmt-text {
    color: var(--text);
    line-height: 1.5;
    flex: 1;
}

.lesson-page .question-separator {
    height: 1px;
    background: var(--border-light);
    margin: 20px 0;
}

.lesson-page .questions-footer {
    background: #EFF6FF;
    border-top: 1px solid var(--border-light);
    padding: 16px 24px;
    display: flex;
    align-items: center;
    gap: 10px;
    color: #1E40AF;
    font-size: 0.875rem;
}

.lesson-page img {
	display:block;
}

/* ========================================
   RESPONSIVE - PAGES
======================================== */

@media (max-width: 1024px) {
    .course-page .lessons-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .lesson-page .current-quizzes-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 20px;
    }
    
    .grade-page .page-header,
    .course-page .course-header,
    .lesson-page .lesson-header {
        padding: 32px 20px;
    }
    
    .grade-page .page-title,
    .course-page .course-title {
        font-size: 1.5rem;
    }
    
    .grade-page .courses-grid-section,
    .course-page .chapters-section {
        padding: 60px 20px;
    }
    
    .grade-page .courses-grid {
        grid-template-columns: 1fr;
    }
    
    .course-page .subject-tabs-section {
        top: 70px;
    }
    
    .course-page .subject-tabs {
        padding: 16px 20px;
    }
    
    .course-page .lessons-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .lesson-page .lesson-main-content {
        display: flex !important;
        flex-direction: column !important;
        gap: 0 !important;
        padding: 40px 20px;
    }
    
    .lesson-page .theory-section {
        order: 1 !important;
    }
    
    .lesson-page .current-quizzes-section {
        order: 2 !important;
        padding: 40px 20px;
    }
    
    .lesson-page .preview-section {
        order: 3 !important;
        padding: 40px 20px;
    }
    
    .lesson-page .lessons-section {
        order: 4 !important;
    }
    
    .lesson-page .theory-column {
        position: static;
    }
    
    .lesson-page .current-quizzes-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .course-page .lessons-grid {
        grid-template-columns: 1fr;
    }
}

/* ========================================
   THÊM PHẦN CSS CÒN THIẾU - COPY NGUYÊN GỐC
======================================== */

/* Lesson Page - Continue */
.lesson-page .quiz-card-title {
    margin: 0;
    font-size: 1.125rem;
    font-weight: 700;
    line-height: 1.4;
    min-height: 48px;
}

.lesson-page .quiz-card-title a {
    color: var(--text);
    text-decoration: none;
    transition: var(--transition);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.lesson-page .quiz-card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.lesson-page .quiz-card-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    padding-top: 12px;
    border-top: 1px solid var(--border-light);
}

.lesson-page .quiz-card-meta .meta-item {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.8125rem;
    color: var(--text-muted);
    font-weight: 600;
}

.lesson-page .quiz-card-meta .meta-item svg {
    opacity: 0.7;
    flex-shrink: 0;
}

.lesson-page .btn-start-quiz {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    background: var(--primary);
    color: white;
    border-radius: var(--radius);
    font-size: 0.9375rem;
    font-weight: 700;
    text-decoration: none;
    transition: var(--transition);
    margin-top: auto;
}

.lesson-page .related-quizzes-section {
    padding: 60px 32px;
    background: white;
}

.lesson-page .related-quizzes-section .container {
    max-width: 1500px;
    margin: 0 auto;
}

.lesson-page .related-quizzes-title {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text);
    margin: 0 0 32px 0;
    display: flex;
    align-items: center;
    gap: 12px;
}

.lesson-page .related-quizzes-title svg {
    color: var(--primary);
    flex-shrink: 0;
}

.lesson-page .related-quiz-item {
    background: white;
    border: 2px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 24px;
    margin-bottom: 20px;
    transition: var(--transition);
}

.lesson-page .related-quiz-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 16px;
}

.lesson-page .quiz-number-badge {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 8px 16px;
    border-radius: 50px;
    font-size: 0.875rem;
    font-weight: 700;
}

.lesson-page .related-quiz-title {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--text);
    margin: 0 0 12px 0;
}

.lesson-page .related-quiz-meta {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
}

.lesson-page .quiz-meta-item {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.875rem;
    color: var(--text-muted);
    font-weight: 500;
}

.lesson-page .quiz-meta-item svg {
    opacity: 0.7;
}

.lesson-page .quiz-action-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    background: var(--primary);
    color: white;
    border-radius: var(--radius);
    font-weight: 700;
    font-size: 0.9375rem;
    text-decoration: none;
    transition: var(--transition);
}

.lesson-page .lessons-column {
    min-width: 450px;
}

.lesson-page .theory-column {
    min-width: 500px;
}

.lesson-page .lesson-main-content {
    grid-template-columns: 500px 1fr;
    gap: 40px;
}

@media (max-width: 1500px) {
    .lesson-page .lesson-main-content {
        grid-template-columns: 450px 1fr;
        gap: 32px;
    }
}

@media (max-width: 1200px) {
    .lesson-page .lesson-main-content {
        grid-template-columns: 400px 1fr;
        gap: 28px;
    }
    
    .lesson-page .theory-column {
        min-width: auto;
    }
    
    .lesson-page .lessons-column {
        min-width: auto;
    }
}

@media (max-width: 1024px) {
    .lesson-page .lesson-main-content {
        display: flex !important;
        flex-direction: column !important;
    }
    
    .lesson-page .container,
    .lesson-page .current-quizzes-section .container,
    .lesson-page .preview-section .container,
    .lesson-page .related-quizzes-section .container {
        max-width: 100%;
        padding: 0 32px;
    }
    
    .lesson-page .lesson-main-content {
        padding: 40px 24px;
    }
}

@media (max-width: 768px) {
    .lesson-page .container,
    .lesson-page .current-quizzes-section .container,
    .lesson-page .preview-section .container,
    .lesson-page .related-quizzes-section .container {
        padding: 0 20px;
    }
    
    .lesson-page .lesson-main-content,
    .lesson-page .current-quizzes-section,
    .lesson-page .preview-section,
    .lesson-page .related-quizzes-section {
        padding: 32px 20px;
    }
}

.lesson-page .question-input-placeholder {
    margin-top: 12px;
}

.lesson-page .question-input-placeholder input {
    width: 100%;
    max-width: 600px;
    padding: 12px 16px;
    border: 2px solid var(--border);
    border-radius: var(--radius);
    font-size: 1rem;
    font-family: inherit;
    background: white;
    color: var(--text);
    cursor: not-allowed;
    transition: var(--transition);
}

.lesson-page .question-input-placeholder input:focus {
    outline: none;
    border-color: var(--primary);
}

.lesson-page .current-quizzes-grid {
    grid-template-columns: repeat(4, 1fr) !important;
    gap: 24px;
}

.lesson-page .related-quiz-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 32px;
    padding: 28px 32px;
}

.lesson-page .related-quiz-content {
    flex: 1;
}

.lesson-page .quiz-action-btn {
    flex-shrink: 0;
    white-space: nowrap;
}

@media (max-width: 1024px) {
    .container {
        padding: 0 20px !important;
    }
    
    .header-container {
        padding: 0 20px !important;
        gap: 20px;
    }
    
    .grade-choose,
    .quiz-latest,
    .steps-section,
    .stats-section,
    .documents-section,
    .feedback-section {
        padding: 60px 20px !important;
    }
    
    .hero-main {
        padding: 60px 20px 80px !important;
    }
    
    .site-footer {
        padding: 60px 20px 32px !important;
    }
    
    .footer-bottom-inner {
        padding: 0 20px !important;
    }
    
    .quiz-grid {
        grid-template-columns: repeat(2, 1fr) !important;
        gap: 20px;
    }
    
    .steps-features {
        grid-template-columns: 1fr !important;
    }
    
    .lesson-page .current-quizzes-grid {
        grid-template-columns: repeat(3, 1fr) !important;
    }
}

@media (max-width: 768px) {
    .header-container {
        height: 70px;
        padding: 0 16px !important;
    }
    
    .logo-text {
        font-size: 1.25rem;
    }
    
    .logo-icon {
        width: 36px;
        height: 36px;
        font-size: 1.125rem;
    }
    
    .mobile-menu-toggle {
        display: block;
    }
    
    .header-nav {
        display: none;
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: white;
        border-bottom: 1px solid #E5E7EB;
        box-shadow: 0 4px 12px rgba(0,0,0,0.1);
        padding: 16px !important;
        z-index: 999;
        max-height: calc(100vh - 70px);
        overflow-y: auto;
    }
    
    .header-nav.active {
        display: block;
    }
    
    .main-menu {
        flex-direction: column;
        gap: 8px;
    }
    
    .main-menu > li > a {
        width: 100%;
        justify-content: space-between;
    }
    
    .sub-menu {
        position: static;
        box-shadow: none;
        border: none;
        background: var(--bg-light);
        margin-top: 8px;
    }
    
    .menu-item-has-children .sub-menu {
        display: none;
    }
    
    .menu-item-has-children.active .sub-menu {
        display: block;
    }
    
    .header-auth {
        flex-direction: column;
        width: 100%;
        margin-top: 16px;
        padding-top: 16px;
        border-top: 1px solid #E5E7EB;
    }
    
    .btn-login,
    .btn-register {
        width: 100%;
        text-align: center;
        justify-content: center;
        display: block;
    }
    
    .container {
        padding: 0 16px !important;
    }
    
    .grade-choose,
    .quiz-latest,
    .steps-section,
    .stats-section,
    .documents-section,
    .feedback-section {
        padding: 50px 16px !important;
    }
    
    .hero-main {
        padding: 50px 16px 70px !important;
    }
    
    .hero-title {
        font-size: 2.25rem;
    }
    
    .hero-layout,
    .steps-bottom,
    .doc-layout {
        grid-template-columns: 1fr !important;
        gap: 40px;
    }
    
    .hero-image {
        order: -1;
    }
    
    .grade-grid,
    .quiz-grid,
    .steps-top,
    .stats-grid,
    .doc-list,
    .feedback-grid,
    .footer-grid {
        grid-template-columns: 1fr !important;
        gap: 20px;
    }
    
    .grade-card {
        flex-direction: column;
        align-items: flex-start;
        padding: 28px !important;
    }
    
    .grade-card-btn {
        width: 100%;
        justify-content: center;
    }
    
    .section-header {
        flex-direction: column;
        gap: 16px;
        align-items: flex-start;
    }
    
    .site-footer {
        padding: 50px 16px 28px !important;
    }
    
    .footer-bottom-inner {
        padding: 0 16px !important;
        flex-direction: column;
        gap: 16px;
        text-align: center;
    }
    
    .grade-page .page-header,
    .grade-page .courses-grid-section {
        padding: 32px 16px !important;
    }
    
    .grade-page .page-title {
        font-size: 1.5rem;
    }
    
    .grade-page .courses-grid {
        grid-template-columns: 1fr !important;
    }
    
    .course-page .subject-tabs-section {
        top: 70px;
    }
    
    .course-page .subject-tabs {
        padding: 16px 20px;
        gap: 8px;
    }
	.course-page .subject-tab {
        min-width: 90px;
        padding: 12px 16px;
    }
    
	.course-page .tab-icon {
        width: 48px;
        height: 48px;
    }
	.course-page .tab-name {
        font-size: 0.8125rem;
    }
	.course-page .subject-tabs-scroll::-webkit-scrollbar {
        height: 4px;
    }
	
    .course-page .course-header,
    .course-page .chapters-section {
        padding: 32px 16px !important;
    }
    
    .course-page .course-title {
        font-size: 1.5rem;
    }
    
    .course-page .lessons-grid {
        grid-template-columns: repeat(2, 1fr) !important;
        gap: 16px;
    }
    
    .lesson-page .lesson-header {
        padding: 32px 16px !important;
    }
    
    .lesson-page .lesson-page-title {
        font-size: 1.5rem;
    }
    
    .lesson-page .lesson-main-content {
        display: flex !important;
        flex-direction: column !important;
        gap: 0 !important;
        padding: 32px 16px !important;
    }
    
    .lesson-page .theory-section {
        order: 1 !important;
        padding-bottom: 32px;
    }
    
    .lesson-page .current-quizzes-section {
        order: 2 !important;
        padding: 32px 16px !important;
    }
    
    .lesson-page .preview-section {
        order: 3 !important;
        padding: 32px 16px !important;
    }
    
    .lesson-page .lessons-section {
        order: 4 !important;
        padding-top: 32px;
    }
    
    .lesson-page .related-quizzes-section {
        padding: 32px 16px !important;
    }
    
    .lesson-page .theory-column {
        position: static;
    }
    
    .lesson-page .current-quizzes-grid {
        grid-template-columns: 1fr !important;
        gap: 16px;
    }
    
    .lesson-page .question-item {
        padding: 20px 16px !important;
    }
    
    .lesson-page .question-input-placeholder input {
        max-width: 100%;
    }
    
    .lesson-page .related-quiz-item {
        flex-direction: column;
        align-items: flex-start;
        padding: 20px 16px !important;
        gap: 16px;
    }
    
    .lesson-page .quiz-action-btn {
        width: 100%;
        justify-content: center;
    }
    
    .lesson-page .container,
    .lesson-page .current-quizzes-section .container,
    .lesson-page .preview-section .container,
    .lesson-page .related-quizzes-section .container {
        padding: 0 16px !important;
    }
}

@media (max-width: 480px) {
    .course-page .lessons-grid {
        grid-template-columns: 1fr !important;
    }
    
    .container,
    .header-container,
    .footer-bottom-inner {
        padding: 0 12px !important;
    }
    
    .grade-choose,
    .quiz-latest,
    .steps-section,
    .stats-section,
    .documents-section,
    .feedback-section,
    .hero-main,
    .site-footer {
        padding-left: 12px !important;
        padding-right: 12px !important;
    }
	.course-page .subject-tabs {
        padding: 12px 16px;
        gap: 6px;
    }
    
    .course-page .subject-tab {
        min-width: 75px;
        padding: 10px 12px;
    }
    
    .course-page .tab-icon {
        width: 40px;
        height: 40px;
    }
    
    .course-page .tab-name {
        font-size: 0.75rem;
    }
}

html {
    overflow-y: scroll !important;
    height: 100%;
}

body {
    overflow-x: hidden !important;
    overflow-y: auto !important;
    min-height: 100vh;
    height: auto !important;
}

html::-webkit-scrollbar {
    width: 12px;
}

html::-webkit-scrollbar-track {
    background: #f1f1f1;
}

html::-webkit-scrollbar-thumb {
    background: #c1c1c1;
    border-radius: 6px;
}

html {
    scrollbar-width: auto;
    scrollbar-color: #c1c1c1 #f1f1f1;
}

.site-header,
.hero-main,
.grade-choose,
.quiz-latest,
.steps-section,
.stats-section,
.documents-section,
.feedback-section,
.site-footer,
.grade-page,
.course-page,
.lesson-page {
    overflow: visible !important;
}

.container,
.header-container {
    overflow: visible !important;
}

.breadcrumb-section {
    background: white;
    border-bottom: 1px solid #E5E7EB;
    padding: 16px 0;
}

.breadcrumb-section .container {
    max-width: 1500px;
    margin: 0 auto;
    padding: 0 32px;
}

.rank-math-breadcrumb {
    font-size: 0.875rem;
    font-weight: 500;
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 8px;
}

.rank-math-breadcrumb p {
    margin: 0;
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 8px;
}

.rank-math-breadcrumb a {
    color: #9CA3AF !important;
    text-decoration: none;
    transition: all 0.3s;
    display: inline-flex;
    align-items: center;
    font-weight: 500;
}

.rank-math-breadcrumb span:last-child {
    color: #111827 !important;
    font-weight: 700 !important;
}

.rank-math-breadcrumb strong {
    color: #111827 !important;
    font-weight: 700 !important;
}

.rank-math-breadcrumb .separator {
    content: '›';
    color: #D1D5DB;
    margin: 0 6px;
    font-weight: 400;
}

.rank-math-breadcrumb > span:not(:last-child)::after {
    content: '›';
    color: #D1D5DB;
    margin: 0 0 0 8px;
    font-weight: 400;
}

.rank-math-breadcrumb > span:last-child::after {
    display: none !important;
}

.rank-math-breadcrumb svg {
    width: 14px;
    height: 14px;
    margin-right: 4px;
    opacity: 0.6;
}

.home-page .breadcrumb-section {
    display: none;
}

.grade-page .breadcrumb-section {
    background: white;
}

.course-page .breadcrumb-section {
    background: white;
}

.lesson-page .breadcrumb-section {
    background: white;
}

.quiz-page .breadcrumb-section {
    background: white;
}

.archive .breadcrumb-section,
.search .breadcrumb-section {
    background: white;
}

@media (max-width: 768px) {
    .breadcrumb-section {
        padding: 12px 0;
    }
    
    .breadcrumb-section .container {
        padding: 0 16px;
    }
    
    .rank-math-breadcrumb {
        font-size: 0.8125rem;
        gap: 6px;
    }
    
    .rank-math-breadcrumb p {
        gap: 6px;
    }
    
    .rank-math-breadcrumb {
        overflow-x: auto;
        white-space: nowrap;
        -webkit-overflow-scrolling: touch;
        scrollbar-width: none;
    }
    
    .rank-math-breadcrumb::-webkit-scrollbar {
        display: none;
    }
}

@media (max-width: 480px) {
    .breadcrumb-section {
        padding: 10px 0;
    }
    
    .breadcrumb-section .container {
        padding: 0 12px;
    }
    
    .rank-math-breadcrumb {
        font-size: 0.75rem;
    }
}

/* KẾT THÚC FILE - GHÉ P VỚI PART 1 */

/* ========================================
   ARCHIVE QUIZ PAGE - ONLY
   Copy nguyên từ file gốc
   CHỈ CSS của archive-quiz.php, KHÔNG CÓ duplicate
======================================== */

/* Archive Page Header */
.archive-quiz-page .archive-page-header {
    background: linear-gradient(135deg, #1E40AF 0%, #1E3A8A 100%);
    padding: 48px 32px;
    position: relative;
    overflow: hidden;
}

.archive-quiz-page .archive-page-header::before {
    content: '';
    position: absolute;
    inset: 0;
    background: 
        radial-gradient(circle at 25% 50%, rgba(255,255,255,0.1) 0%, transparent 50%),
        radial-gradient(circle at 75% 60%, rgba(255,255,255,0.08) 0%, transparent 50%);
}

.archive-quiz-page .archive-page-header .container {
    max-width: 1500px;
    margin: 0 auto;
    position: relative;
    z-index: 2;
}

.archive-quiz-page .archive-page-title {
    font-size: 2.25rem;
    font-weight: 900;
    color: white;
    margin: 0 0 12px 0;
    letter-spacing: -0.02em;
}

.archive-quiz-page .archive-page-subtitle {
    font-size: 1.125rem;
    color: rgba(255,255,255,0.95);
    margin: 0;
    font-weight: 500;
}

/* Archive Content Section */
.archive-quiz-page .archive-content-section {
    padding: 60px 32px;
    background: #FAFBFC;
}

.archive-quiz-page .archive-content-section .container {
    max-width: 1500px;
    margin: 0 auto;
}

/* Archive Layout - 2 Columns */
.archive-quiz-page .archive-layout {
    display: grid;
    grid-template-columns: 1fr 380px;
    gap: 40px;
    align-items: start;
}

/* ===== LEFT COLUMN - QUIZZES LIST ===== */

.archive-quiz-page .archive-main-content {
    display: flex;
    flex-direction: column;
    gap: 28px;
}

/* Stats Bar */
.archive-quiz-page .archive-stats-bar {
    background: white;
    border: 2px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 20px 28px;
    display: flex;
    gap: 32px;
    align-items: center;
    box-shadow: var(--shadow-sm);
}

.archive-quiz-page .archive-stats-bar .stats-item {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-light);
    font-weight: 600;
    font-size: 0.9375rem;
}

.archive-quiz-page .archive-stats-bar .stats-item svg {
    color: var(--primary);
    flex-shrink: 0;
}

/* Quizzes Grid */
.archive-quiz-page .archive-quizzes-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

/* Quiz Card */
.archive-quiz-page .archive-quiz-card {
    background: white;
    border: 2px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 28px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

/* Quiz Card Header */
.archive-quiz-page .quiz-card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.archive-quiz-page .quiz-difficulty-badge {
    display: inline-block;
    padding: 6px 14px;
    border-radius: 50px;
    font-size: 0.75rem;
    font-weight: 700;
}

.archive-quiz-page .quiz-difficulty-badge.difficulty-easy {
    background: #D1FAE5;
    color: #059669;
}

.archive-quiz-page .quiz-difficulty-badge.difficulty-medium {
    background: #FEF3C7;
    color: #D97706;
}

.archive-quiz-page .quiz-difficulty-badge.difficulty-hard {
    background: #FED7AA;
    color: #EA580C;
}

.archive-quiz-page .quiz-difficulty-badge.difficulty-very-hard {
    background: #FEE2E2;
    color: #DC2626;
}

/* Quiz Card Title */
.archive-quiz-page .quiz-card-title {
    margin: 0;
    font-size: 1.125rem;
    font-weight: 700;
    line-height: 1.5;
    min-height: 54px;
}

.archive-quiz-page .quiz-card-title a {
    color: var(--text);
    text-decoration: none;
    transition: var(--transition);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* Quiz Card Lesson */
.archive-quiz-page .quiz-card-lesson {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 14px;
    background: #EFF6FF;
    border-radius: var(--radius);
    border: 1px solid #DBEAFE;
}

.archive-quiz-page .quiz-card-lesson svg {
    color: var(--accent);
    flex-shrink: 0;
}

.archive-quiz-page .quiz-card-lesson span {
    color: var(--accent);
    font-size: 0.875rem;
    font-weight: 600;
    line-height: 1.4;
}

/* Quiz Card Meta */
.archive-quiz-page .quiz-card-meta {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 12px;
    padding-top: 12px;
    border-top: 1px solid var(--border-light);
}

.archive-quiz-page .quiz-card-meta .meta-item {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.875rem;
    color: var(--text-muted);
    font-weight: 600;
}

.archive-quiz-page .quiz-card-meta .meta-item svg {
    opacity: 0.7;
    flex-shrink: 0;
}

.archive-quiz-page .quiz-card-meta .meta-divider {
    color: var(--border);
    font-weight: 400;
}

/* Quiz Card Actions */
.archive-quiz-page .quiz-card-actions {
    margin-top: auto;
}

.archive-quiz-page .btn-start-quiz {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    width: 100%;
    padding: 12px 24px;
    background: var(--primary);
    color: white;
    border-radius: var(--radius);
    font-size: 0.9375rem;
    font-weight: 700;
    text-decoration: none;
    transition: var(--transition);
}

.archive-quiz-page .btn-start-quiz svg {
    flex-shrink: 0;
}

/* Pagination */
.archive-quiz-page .archive-pagination {
    margin-top: 40px;
}

.archive-quiz-page .pagination {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.archive-quiz-page .pagination .nav-links {
    display: flex;
    align-items: center;
    gap: 8px;
}

.archive-quiz-page .pagination a,
.archive-quiz-page .pagination .current {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 44px;
    height: 44px;
    padding: 0 16px;
    background: white;
    border: 2px solid var(--border);
    border-radius: var(--radius);
    color: var(--text);
    font-weight: 700;
    font-size: 0.9375rem;
    text-decoration: none;
    transition: var(--transition);
}

.archive-quiz-page .pagination .current {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

.archive-quiz-page .pagination .prev,
.archive-quiz-page .pagination .next {
    gap: 6px;
}

.archive-quiz-page .pagination svg {
    flex-shrink: 0;
}

/* No Quizzes Found */
.archive-quiz-page .no-quizzes-found {
    background: white;
    border: 2px solid var(--border);
    border-radius: var(--radius-xl);
    padding: 60px 40px;
    text-align: center;
}

.archive-quiz-page .no-results-icon {
    margin-bottom: 24px;
}

.archive-quiz-page .no-results-icon svg {
    color: var(--text-muted);
    opacity: 0.5;
}

.archive-quiz-page .no-quizzes-found h3 {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text);
    margin: 0 0 12px 0;
}

.archive-quiz-page .no-quizzes-found p {
    color: var(--text-light);
    font-size: 1rem;
    margin: 0 0 24px 0;
}

.archive-quiz-page .btn-back-home {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 32px;
    background: var(--primary);
    color: white;
    border-radius: var(--radius);
    font-weight: 700;
    font-size: 1rem;
    text-decoration: none;
    transition: var(--transition);
}

/* ===== RIGHT SIDEBAR - GRADES ===== */

.archive-quiz-page .archive-sidebar {
    position: sticky;
    top: 100px;
}

/* Sidebar Widget */
.archive-quiz-page .sidebar-widget {
    background: white;
    border: 2px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.archive-quiz-page .widget-title {
    background: linear-gradient(135deg, #EFF6FF 0%, #DBEAFE 100%);
    padding: 20px 24px;
    margin: 0;
    font-size: 1.125rem;
    font-weight: 800;
    color: var(--accent);
    display: flex;
    align-items: center;
    gap: 10px;
    border-bottom: 2px solid var(--border-light);
}

.archive-quiz-page .widget-title svg {
    flex-shrink: 0;
}

/* Grades List */
.archive-quiz-page .grades-list {
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.archive-quiz-page .grade-item {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 16px 18px;
    background: #FAFBFC;
    border: 2px solid var(--border);
    border-radius: var(--radius);
    text-decoration: none;
    transition: var(--transition);
}

.archive-quiz-page .grade-item.active {
    background: linear-gradient(135deg, rgba(249,115,22,0.05) 0%, rgba(234,88,12,0.05) 100%);
    border-color: var(--primary);
    box-shadow: var(--shadow-sm);
}

.archive-quiz-page .grade-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, #FFF7ED 0%, #FFEDD5 100%);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.archive-quiz-page .grade-icon svg {
    color: var(--primary);
}

.archive-quiz-page .grade-item.active .grade-icon {
    background: var(--primary);
}

.archive-quiz-page .grade-item.active .grade-icon svg {
    color: white;
}

.archive-quiz-page .grade-info {
    flex: 1;
}

.archive-quiz-page .grade-name {
    font-size: 1rem;
    font-weight: 700;
    color: var(--text);
}

.archive-quiz-page .grade-item.active .grade-name {
    color: var(--primary);
}

.archive-quiz-page .grade-arrow {
    color: var(--text-muted);
    flex-shrink: 0;
    opacity: 0;
    transform: translateX(-4px);
    transition: var(--transition);
}

.archive-quiz-page .grade-item.active .grade-arrow {
    opacity: 1;
    transform: translateX(0);
    color: var(--primary);
}

.archive-quiz-page .no-grades {
    padding: 24px;
    text-align: center;
}

.archive-quiz-page .no-grades p {
    margin: 0;
    color: var(--text-muted);
    font-size: 0.9375rem;
}

/* ========================================
   RESPONSIVE - DESKTOP & LAPTOP
======================================== */

@media (max-width: 1200px) {
    .archive-quiz-page .archive-layout {
        grid-template-columns: 1fr 340px;
        gap: 32px;
    }
    
    .archive-quiz-page .archive-quizzes-grid {
        grid-template-columns: 1fr;
    }
}

/* ========================================
   RESPONSIVE - TABLET
======================================== */

@media (max-width: 1024px) {
    .archive-quiz-page .archive-layout {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .archive-quiz-page .archive-sidebar {
        position: static;
    }
    
    .archive-quiz-page .archive-quizzes-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* ========================================
   RESPONSIVE - MOBILE
======================================== */

@media (max-width: 768px) {
    .archive-quiz-page .archive-page-header {
        padding: 36px 16px;
    }
    
    .archive-quiz-page .archive-page-title {
        font-size: 1.75rem;
    }
    
    .archive-quiz-page .archive-page-subtitle {
        font-size: 1rem;
    }
    
    .archive-quiz-page .archive-content-section {
        padding: 40px 16px;
    }
    
    .archive-quiz-page .archive-stats-bar {
        flex-direction: column;
        align-items: flex-start;
        gap: 16px;
        padding: 20px;
    }
    
    .archive-quiz-page .archive-quizzes-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .archive-quiz-page .archive-quiz-card {
        padding: 24px 20px;
    }
    
    .archive-quiz-page .archive-sidebar {
        position: static;
        max-width: 100%;
        margin: 0;
    }
    
    .archive-quiz-page .sidebar-widget {
        width: 100%;
    }
    
    .archive-quiz-page .grades-list {
        padding: 12px;
    }
    
    .archive-quiz-page .grade-item {
        padding: 14px 16px;
        width: 100%;
    }
}

/* ========================================
   RESPONSIVE - SMALL MOBILE
======================================== */

@media (max-width: 480px) {
    .archive-quiz-page .archive-page-header {
        padding: 32px 12px;
    }
    
    .archive-quiz-page .archive-page-title {
        font-size: 1.5rem;
    }
    
    .archive-quiz-page .archive-content-section {
        padding: 32px 12px;
    }
    
    .archive-quiz-page .archive-quiz-card {
        padding: 20px 16px;
    }
    
    .archive-quiz-page .quiz-card-title {
        font-size: 1rem;
    }
    
    .archive-quiz-page .btn-start-quiz {
        padding: 10px 20px;
        font-size: 0.875rem;
    }
    
    .archive-quiz-page .grades-list {
        padding: 10px;
    }
    
    .archive-quiz-page .grade-item {
        padding: 12px 14px;
    }
    
    .archive-quiz-page .grade-icon {
        width: 36px;
        height: 36px;
    }
    
    .archive-quiz-page .grade-name {
        font-size: 0.9375rem;
    }
}

/* ========================================
   THPT & ĐGNL PAGES CSS
   Dùng cho: single-thpt_subject.php & single-dgnl_subject.php
   Cả 2 file đều dùng class="course-page"
   KHÔNG CÓ HOVER
======================================== */

/* Subject Tabs Section */
.course-page .course-tabs-section {
    background: #fff;
    border-bottom: 1px solid #E5E7EB;
    position: sticky;
    top: 80px;
    z-index: 100;
    box-shadow: 0 2px 4px rgba(0,0,0,0.02);
}

.course-page .course-tabs-section .container {
    max-width: 1500px;
    margin: 0 auto;
}

.course-page .course-tabs {
    display: flex;
    gap: 15px;
    padding: 20px 0;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
}

.course-page .course-tabs::-webkit-scrollbar {
    display: none;
}

.course-page .course-tab {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    padding: 10px 15px;
    text-decoration: none;
    color: #666;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.2s;
    border-radius: 8px;
    min-width: 80px;
    flex-shrink: 0;
}

.course-page .course-tab img {
    width: 48px;
    height: 48px;
    object-fit: contain;
}

.course-page .course-tab span {
	font-weight: 700;
    text-align: center;
    white-space: nowrap;
}

.course-page .course-tab.active {
    color: #ff6b35;
    border-bottom: 3px solid #ff6b35;
}

/* Course Hero */
.course-page .course-hero {
    background: linear-gradient(135deg, #4461c5 0%, #2d3e91 100%);
    color: #fff;
    padding: 50px 20px;
}

.course-page .course-hero .container {
    max-width: 1500px;
    margin: 0 auto;
}

.course-page .course-hero h1 {
    font-size: 36px;
    font-weight: 700;
    margin: 0;
    text-align: left;
}

/* Content Wrapper */
.course-page .course-content-wrapper {
    background: #fff;
    padding: 30px 0 50px 0;
}

.course-page .course-content-wrapper .container {
    max-width: 1500px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Course Intro */
.course-page .course-intro {
    margin-bottom: 30px;
    padding: 20px;
    background: #f9f9f9;
    border-radius: 8px;
}

.course-page .course-intro p {
    margin: 0;
    line-height: 1.6;
}

/* Chapter Title */
.course-page .chapter-title {
    font-size: 20px;
    font-weight: 800;
    color: #1e3a8a;
    margin: 40px 0 25px 0;
    padding-left: 15px;
    border-left: 4px solid #ff6b35;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.course-page .chapter-title:first-of-type {
    margin-top: 0;
}

.course-page .chapter-intro {
    margin-bottom: 25px;
    color: #666;
    line-height: 1.6;
}

/* Quiz Cards Grid */
.course-page .quiz-cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 24px;
    margin-bottom: 40px;
}

/* Quiz Item Card */
.course-page .quiz-item-card {
    background: #fff;
    border: 1px solid #e8e8e8;
    border-radius: 16px;
    padding: 24px;
    padding-top: 50px;
    transition: all 0.3s ease;
    position: relative;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
	display: flex;
    flex-direction: column;
}

/* Quiz Badge */
.course-page .quiz-badge {
    position: absolute;
    top: 16px;
    left: 16px;
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.course-page .quiz-badge.easy {
    background: #d4f4dd;
    color: #2d7a4a;
}

.course-page .quiz-badge.medium {
    background: #fff3cd;
    color: #856404;
}

.course-page .quiz-badge.hard {
    background: #ffe5d9;
    color: #d63801;
}

.course-page .quiz-badge.very-hard {
    background: #ffe0e0;
    color: #c62828;
}

/* Quiz Title */
.course-page .quiz-item-title {
    font-size: 16px;
    font-weight: 800;
    margin: 8px 0 16px 0;
    line-height: 1.5;
    min-height: 48px;
	flex: 1;
}

.course-page .quiz-item-title a {
    color: #1a1a1a;
	font-weight: 700;
    text-decoration: none;
    transition: color 0.2s;
}

/* Quiz Meta */
.course-page .quiz-item-meta {
    display: flex;
    gap: 16px;
    margin-bottom: 20px;
    padding: 16px 0;
    border-top: 1px solid #f0f0f0;
    border-bottom: 1px solid #f0f0f0;
    flex-wrap: wrap;
}

.course-page .quiz-item-meta span {
    display: flex;
    align-items: center;
    gap: 6px;
    color: #666;
    font-size: 14px;
    font-weight: 500;
}

.course-page .quiz-questions:before {
    content: "📝";
    font-size: 16px;
}

.course-page .quiz-time:before {
    content: "⏱";
    font-size: 16px;
}

.course-page .quiz-date:before {
    content: "📅";
    font-size: 16px;
}

/* Quiz Start Button */
.course-page .quiz-start-btn {
    display: block;
    width: 100%;
    background: linear-gradient(135deg, #ff6b35 0%, #e55a2b 100%);
    color: #fff;
    text-align: center;
    padding: 14px 24px;
    border-radius: 10px;
    text-decoration: none;
    font-weight: 700;
    font-size: 15px;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(255, 107, 53, 0.2);
	margin-top: auto;
}

.course-page .quiz-start-btn:before {
    content: "▶";
    margin-right: 8px;
    font-size: 12px;
}

/* No Categories */
.course-page .no-categories {
    text-align: center;
    padding: 40px 20px;
}

.course-page .no-categories p {
    color: #999;
    margin: 0;
}

.course-page .no-categories a {
    color: #ff6b35;
    text-decoration: underline;
}

/* ========================================
   THPT ARCHIVE PAGE
======================================== */

.thpt-archive {
    background: #f5f5f5;
    min-height: 100vh;
}

.thpt-archive .page-header {
    background: linear-gradient(135deg, #4461c5 0%, #2d3e91 100%);
    color: #fff;
    padding: 60px 20px;
    text-align: center;
}

.thpt-archive .page-header h1 {
    font-size: 36px;
    font-weight: 700;
    margin: 0 0 10px 0;
}

.thpt-archive .page-header p {
    font-size: 18px;
    margin: 0;
    opacity: 0.9;
}

.thpt-archive .subjects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
    padding: 40px 0;
}

.thpt-archive .subject-card {
    background: #fff;
    border-radius: 8px;
    padding: 30px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    transition: transform 0.2s, box-shadow 0.2s;
}

.thpt-archive .subject-card h3 {
    font-size: 20px;
    font-weight: 600;
    margin: 0 0 20px 0;
    color: #1a1a1a;
}

.thpt-archive .btn-subject {
    display: block;
    background: #ff6b35;
    color: #fff;
    text-align: center;
    padding: 14px 20px;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    font-size: 15px;
    transition: background 0.2s;
}

/* ========================================
   ĐGNL ARCHIVE PAGE
======================================== */

.dgnl-archive {
    background: #f5f5f5;
    min-height: 100vh;
}

.dgnl-archive .page-header {
    background: linear-gradient(135deg, #4461c5 0%, #2d3e91 100%);
    color: #fff;
    padding: 60px 20px;
    text-align: center;
}

.dgnl-archive .page-header h1 {
    font-size: 36px;
    font-weight: 700;
    margin: 0 0 10px 0;
}

.dgnl-archive .page-header p {
    font-size: 18px;
    margin: 0;
    opacity: 0.9;
}

.dgnl-archive .subjects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
    padding: 40px 0;
}

.dgnl-archive .subject-card {
    background: #fff;
    border-radius: 8px;
    padding: 30px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    transition: transform 0.2s, box-shadow 0.2s;
}

.dgnl-archive .subject-card h3 {
    font-size: 20px;
    font-weight: 600;
    margin: 0 0 20px 0;
    color: #1a1a1a;
}

.dgnl-archive .btn-subject {
    display: block;
    background: #ff6b35;
    color: #fff;
    text-align: center;
    padding: 14px 20px;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    font-size: 15px;
    transition: background 0.2s;
}

/* ========================================
   RESPONSIVE
======================================== */

@media (max-width: 768px) {
    .course-page .course-hero {
        padding: 40px 20px;
    }
    
    .course-page .course-hero h1 {
        font-size: 26px;
    }
    
    .course-page .course-tabs-section {
        padding: 15px 0;
        top: 70px;
    }
    
    .course-page .course-tabs {
        gap: 10px;
        padding: 0 15px;
    }
    
    .course-page .course-tab {
        min-width: 70px;
        padding: 8px 10px;
    }
    
    .course-page .course-tab img {
        width: 40px;
        height: 40px;
    }
    
    .course-page .course-tab span {
        font-size: 12px;
    }
    
    .course-page .course-content-wrapper {
        padding: 20px 0 40px 0;
    }
    
    .course-page .chapter-title {
        font-size: 18px;
        margin: 30px 0 20px 0;
    }
    
    .course-page .quiz-cards-grid {
        grid-template-columns: 1fr;
        gap: 20px;
        margin-bottom: 30px;
    }
    
    .course-page .quiz-item-card {
        padding: 20px;
        padding-top: 46px;
    }
    
    .course-page .quiz-badge {
        top: 12px;
        left: 12px;
        font-size: 11px;
        padding: 5px 12px;
    }
    
    .course-page .quiz-item-meta {
        gap: 12px;
    }
    
    .thpt-archive .page-header,
    .dgnl-archive .page-header {
        padding: 40px 20px;
    }
    
    .thpt-archive .page-header h1,
    .dgnl-archive .page-header h1 {
        font-size: 28px;
    }
    
    .thpt-archive .page-header p,
    .dgnl-archive .page-header p {
        font-size: 16px;
    }
    
    .thpt-archive .subjects-grid,
    .dgnl-archive .subjects-grid {
        grid-template-columns: 1fr;
        padding: 20px 0;
    }
    
    .thpt-archive .subject-card,
    .dgnl-archive .subject-card {
        padding: 20px;
    }
}

/* ============================================
   404 ERROR PAGE - COMPLETE STYLES
   Thêm vào style.css
   ============================================ */

.error-404-page {
    min-height: 80vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px 20px;
    background: linear-gradient(135deg, #f9fafb 0%, #ffffff 100%);
}

.error-container {
    max-width: 800px;
    width: 100%;
    text-align: center;
}

/* Error Animation */
.error-animation {
    margin-bottom: 40px;
}

.error-number {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 20px;
    margin-bottom: 20px;
}

.digit {
    font-size: 120px;
    font-weight: 900;
    color: #f97316;
    line-height: 1;
}

.digit.searching {
    position: relative;
    width: 120px;
    height: 120px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.magnifier {
    stroke: #f97316;
    animation: rotate404 3s linear infinite;
}

@keyframes rotate404 {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.error-title {
    font-size: 32px;
    font-weight: 700;
    color: #1f2937;
    margin-bottom: 10px;
}

.error-description {
    font-size: 18px;
    color: #6b7280;
    margin: 0 0 40px 0;
}

/* Search Section */
.error-search-section {
    margin: 40px 0;
}

.search-prompt {
    font-size: 16px;
    color: #4b5563;
    margin-bottom: 16px;
}

/* Error Actions */
.error-actions {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
    margin: 40px 0;
}

.btn-primary,
.btn-secondary {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.2s;
}

.btn-primary {
    background: #f97316;
    color: white;
}

.btn-primary:hover {
    background: #ea580c;
    transform: translateY(-2px);
}

.btn-secondary {
    background: white;
    color: #1f2937;
    border: 2px solid #e5e7eb;
}

.btn-secondary:hover {
    border-color: #f97316;
    color: #f97316;
}

/* Popular Section */
.popular-section {
    margin-top: 60px;
}

.popular-section h2 {
    font-size: 24px;
    font-weight: 700;
    color: #1f2937;
    margin-bottom: 24px;
}

.popular-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 16px;
}

.popular-item {
    background: white;
    padding: 20px;
    border-radius: 12px;
    border: 2px solid #e5e7eb;
    text-decoration: none;
    transition: all 0.2s;
}

.popular-item:hover {
    border-color: #f97316;
    transform: translateY(-4px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
}

.popular-item h3 {
    font-size: 16px;
    font-weight: 600;
    color: #1f2937;
    margin: 0 0 8px 0;
}

.popular-item p {
    font-size: 14px;
    color: #6b7280;
    margin: 0;
}

/* ============================================
   RESPONSIVE
   ============================================ */

@media (max-width: 768px) {
    .digit {
        font-size: 80px;
    }
    
    .digit.searching {
        width: 80px;
        height: 80px;
    }
    
    .magnifier {
        width: 80px;
        height: 80px;
    }
    
    .error-title {
        font-size: 24px;
    }
    
    .error-description {
        font-size: 16px;
    }
    
    .error-actions {
        flex-direction: column;
    }
    
    .btn-primary,
    .btn-secondary {
        width: 100%;
        justify-content: center;
    }
    
    .popular-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .error-404-page {
        padding: 30px 16px;
    }
    
    .digit {
        font-size: 60px;
    }
    
    .digit.searching {
        width: 60px;
        height: 60px;
    }
    
    .error-title {
        font-size: 20px;
    }
}

/* ============================================
   CUSTOM LOGO STYLES
   ============================================ */

/* Logo Container */
.site-logo {
    display: flex;
    align-items: center;
    flex-shrink: 0;
}

.site-logo > a {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    color: inherit;
}

/* Custom Logo Image - TĂNG KÍCH THƯỚC */
.custom-logo-link {
    display: inline-flex;
    align-items: center;
    line-height: 0;
}

.custom-logo {
    max-height: 80px;  /* Tăng từ 50px lên 80px */
    width: auto;
    height: auto;
    vertical-align: middle;
    transition: opacity 0.2s;
}

.custom-logo:hover {
    opacity: 0.8;
}

/* Fallback Logo (Icon + Text) khi chưa upload logo */
.logo-icon {
    width: 50px;  /* Tăng từ 40px */
    height: 50px; /* Tăng từ 40px */
    background: linear-gradient(135deg, #f97316 0%, #ea580c 100%);
    color: white;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;  /* Tăng từ 20px */
    font-weight: 700;
    flex-shrink: 0;
}

.logo-text {
    font-size: 20px;  /* Tăng từ 18px */
    font-weight: 700;
    color: #1f2937;
    white-space: nowrap;
}

/* Khi có custom logo - ẩn text fallback */
.custom-logo-link ~ .logo-text {
    display: none;
}

/* Responsive */
@media (max-width: 1024px) {
    .custom-logo {
        max-height: 70px;  /* Tablet: 70px */
    }
}

@media (max-width: 768px) {
    .custom-logo {
        max-height: 60px;  /* Mobile: 60px thay vì 40px */
    }
    
    .logo-icon {
        width: 45px;
        height: 45px;
        font-size: 22px;
    }
    
    .logo-text {
        font-size: 18px;
    }
}

@media (max-width: 480px) {
    .custom-logo {
        max-height: 50px;  /* Mobile nhỏ: 50px thay vì 35px */
    }
    
    .logo-icon {
        width: 40px;
        height: 40px;
        font-size: 20px;
    }
    
    .logo-text {
        font-size: 16px;
        display: none; /* Ẩn text trên mobile nhỏ */
    }
}

/* Nếu muốn logo CỰC TO cho desktop lớn */
@media (min-width: 1400px) {
    .custom-logo {
        max-height: 75px;  /* Desktop lớn: 100px */
    }
}

/* ============================================
   AJAX SEARCH BOX STYLES
   Thêm vào CUỐI file style.css
   ============================================ */

/* Search Wrapper */
.ajax-search-wrapper {
    position: relative;
    width: 100%;
    max-width: 500px;
}

.ajax-search-hero {
    max-width: 100%;
}

.ajax-search-404 {
    max-width: 600px;
    margin: 0 auto;
}

/* Search Input Group */
.ajax-search-input-group {
    position: relative;
    display: flex;
    align-items: center;
    background: white;
    border: 2px solid #e5e7eb;
    border-radius: 12px;
    transition: all 0.3s;
    padding: 0 12px;
}

.ajax-search-input-group:focus-within {
    border-color: #f97316;
    box-shadow: 0 0 0 3px rgba(249, 115, 22, 0.1);
}

/* Hero Search Styling */
.search-hero-input {
    background: white;
    padding: 8px 16px;
    border-radius: 16px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.15);
}

/* Search Icon */
.ajax-search-icon {
    color: #9ca3af;
    flex-shrink: 0;
    pointer-events: none;
    z-index: 1;
}

/* Search Input Field */
.ajax-search-input {
    flex: 1;
    border: none;
    background: transparent;
    padding: 12px 12px;
    font-size: 15px;
    color: #1f2937;
    outline: none;
    width: 100%;
}

.ajax-search-input::placeholder {
    color: #9ca3af;
}

.search-field-hero {
    font-size: 16px;
    padding: 12px;
}

/* Clear Button */
.ajax-search-clear {
    background: none;
    border: none;
    color: #9ca3af;
    cursor: pointer;
    padding: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 4px;
    transition: all 0.2s;
    flex-shrink: 0;
}

.ajax-search-clear:hover {
    background: #f3f4f6;
    color: #6b7280;
}

/* Dropdown Container */
.ajax-search-dropdown {
    position: absolute;
    top: calc(100% + 8px);
    left: 0;
    right: 0;
    background: white;
    border-radius: 12px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.15);
    max-height: 400px;
    overflow-y: auto;
    z-index: 1000;
    border: 1px solid #e5e7eb;
}

.ajax-search-dropdown::-webkit-scrollbar {
    width: 6px;
}

.ajax-search-dropdown::-webkit-scrollbar-thumb {
    background: #d1d5db;
    border-radius: 3px;
}

.ajax-search-dropdown::-webkit-scrollbar-track {
    background: #f9fafb;
}

/* Results Container */
.search-results-container {
    padding: 8px;
}

/* Result Item */
.search-result-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px;
    border-radius: 8px;
    text-decoration: none;
    color: #1f2937;
    transition: all 0.2s;
    cursor: pointer;
}

.search-result-item:hover {
    background: #f9fafb;
}

.search-result-item.result-type-lesson:hover {
    background: #eff6ff;
}

.search-result-item.result-type-quiz:hover {
    background: #fffbeb;
}

.search-result-item.result-type-course:hover {
    background: #f0fdf4;
}

/* Result Icon */
.result-icon {
    flex-shrink: 0;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    background: #f3f4f6;
}

.result-type-lesson .result-icon {
    background: #dbeafe;
    color: #1e40af;
}

.result-type-quiz .result-icon {
    background: #fef3c7;
    color: #b45309;
}

.result-type-course .result-icon {
    background: #dcfce7;
    color: #166534;
}

/* Result Content */
.result-content {
    flex: 1;
    min-width: 0;
}

.result-title {
    font-size: 14px;
    font-weight: 600;
    color: #1f2937;
    margin-bottom: 2px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.result-title mark {
    background: #fef3c7;
    color: #b45309;
    padding: 2px 4px;
    border-radius: 3px;
    font-weight: 700;
}

.result-meta {
    font-size: 12px;
    color: #6b7280;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* Result Arrow */
.result-arrow {
    flex-shrink: 0;
    color: #d1d5db;
    transition: all 0.2s;
}

.search-result-item:hover .result-arrow {
    color: #f97316;
    transform: translateX(4px);
}

/* Loading State */
.search-loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 40px 20px;
    gap: 12px;
}

.loading-spinner {
    width: 32px;
    height: 32px;
    border: 3px solid #f3f4f6;
    border-top-color: #f97316;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.search-loading span {
    font-size: 14px;
    color: #6b7280;
}

/* No Results State */
.search-no-results {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 40px 20px;
    gap: 12px;
}

.search-no-results svg {
    color: #d1d5db;
}

.search-no-results p {
    font-size: 14px;
    color: #6b7280;
    margin: 0;
}

/* ============================================
   RESPONSIVE
   ============================================ */

@media (max-width: 768px) {
    .ajax-search-wrapper {
        max-width: 100%;
    }
    
    .ajax-search-dropdown {
        max-height: 300px;
    }
    
    .ajax-search-input {
        font-size: 14px;
        padding: 10px;
    }
    
    .result-title {
        font-size: 13px;
    }
    
    .result-meta {
        font-size: 11px;
    }
    
    .result-icon {
        width: 32px;
        height: 32px;
    }
}

@media (max-width: 480px) {
    .ajax-search-input {
        padding: 10px 8px;
    }
}

/* ============================================
   HEADER SEARCH (giữa logo và menu)
   ============================================ */

.site-header .ajax-search-wrapper {
    flex: 1;
    max-width: 400px;
    margin: 0 20px;
}

@media (max-width: 1024px) {
    .site-header .ajax-search-wrapper {
        max-width: 300px;
        margin: 0 16px;
    }
}

@media (max-width: 768px) {
    .site-header .ajax-search-wrapper {
        display: none; /* Ẩn trên mobile */
    }
}

/* ============================================
   MENU RESPONSIVE - FULL VERSION
   BỔ SUNG + HIỆU ỨNG - GIỮ WRAP
   Thêm vào CUỐI style.css (XÓA 2 file cũ nếu đã paste)
   ============================================ */

/* ===== SỬA LẠI HEADER CONTAINER - Cho phép menu wrap ===== */
.header-container {
    min-height: 80px !important;
    flex-wrap: nowrap !important;
}

/* ===== SỬA LẠI MAIN MENU - Cho phép wrap xuống dòng ===== */
.main-menu {
    flex-wrap: wrap !important;
    max-width: 100%;
}

/* ===== SỬA LẠI MENU ITEMS - Giới hạn width + Hiệu ứng ===== */
@media (min-width: 769px) {
    .main-menu > li > a {
        max-width: 200px !important;
        overflow: hidden;
        text-overflow: ellipsis;
        position: relative;
    }
    
    /* Underline animation khi hover */
    .main-menu > li > a::before {
        content: '';
        position: absolute;
        bottom: 0;
        left: 50%;
        width: 0;
        height: 2px;
        background: linear-gradient(90deg, #f97316, #ea580c);
        transform: translateX(-50%);
        transition: width 0.3s ease;
        z-index: 1;
    }
    
    .main-menu > li > a:hover::before,
    .main-menu > li.current-menu-item > a::before {
        width: 80%;
    }
}

/* ===== BỔ SUNG: MOBILE MENU TOGGLE ===== */
.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    padding: 8px;
    cursor: pointer;
    z-index: 1001;
}

.mobile-menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: #1f2937;
    margin: 5px 0;
    transition: all 0.3s ease;
    border-radius: 2px;
    transform-origin: center;
}

.mobile-menu-toggle:active span {
    transform: scale(0.95);
}

.mobile-menu-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
}

.mobile-menu-toggle.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* ===== DROPDOWN MENU - Hiệu ứng ===== */
@media (min-width: 769px) {
    .sub-menu {
        animation: slideDown 0.25s ease !important;
    }
    
    @keyframes slideDown {
        0% {
            opacity: 0;
            transform: translateY(-10px);
        }
        100% {
            opacity: 1;
            transform: translateY(0);
        }
    }
    
    /* Dropdown items xuất hiện lần lượt */
    .sub-menu li {
        opacity: 0;
        animation: fadeInItem 0.3s ease forwards;
    }
    
    .sub-menu li:nth-child(1) { animation-delay: 0.05s; }
    .sub-menu li:nth-child(2) { animation-delay: 0.1s; }
    .sub-menu li:nth-child(3) { animation-delay: 0.15s; }
    .sub-menu li:nth-child(4) { animation-delay: 0.2s; }
    .sub-menu li:nth-child(5) { animation-delay: 0.25s; }
    
    @keyframes fadeInItem {
        to { opacity: 1; }
    }
    
    /* Hover effect cho submenu items */
    .sub-menu li a {
        position: relative;
        transition: all 0.2s ease, padding-left 0.3s ease !important;
    }
    
    .sub-menu li a::before {
        content: '';
        position: absolute;
        left: 0;
        top: 50%;
        transform: translateY(-50%);
        width: 0;
        height: 0;
        border-left: 4px solid #f97316;
        border-top: 4px solid transparent;
        border-bottom: 4px solid transparent;
        opacity: 0;
        transition: all 0.3s ease;
    }
    
    .sub-menu li a:hover::before {
        opacity: 1;
        width: 4px;
    }
    
    .sub-menu li a:hover {
        padding-left: 20px !important;
    }
}

/* ===== AUTH BUTTONS - Hiệu ứng ===== */
.btn-login {
    position: relative;
    overflow: hidden;
}

.btn-login::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(249,115,22,0.1);
    transform: translate(-50%, -50%);
    transition: width 0.4s ease, height 0.4s ease;
    z-index: 0;
}

.btn-login:hover::before {
    width: 200px;
    height: 200px;
}

.btn-register {
    position: relative;
    overflow: hidden;
}

.btn-register::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 50%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
    transition: left 0.5s ease;
    z-index: 0;
}

.btn-register:hover::before {
    left: 150%;
}

/* ===== LOGO HOVER ===== */
.site-logo a {
    transition: all 0.3s ease;
}

.site-logo a:hover {
    transform: translateY(-2px);
}

.logo-icon {
    transition: all 0.3s ease !important;
}

.site-logo a:hover .logo-icon {
    box-shadow: 0 4px 12px rgba(249,115,22,0.3);
    transform: rotate(-5deg);
}

.custom-logo {
    transition: all 0.3s ease !important;
}

.site-logo a:hover .custom-logo {
    transform: scale(1.05);
}

/* ===== MENU ARROW ROTATION ===== */
.menu-item-has-children > a::after {
    transition: all 0.3s ease !important;
}

@media (min-width: 769px) {
    .menu-item-has-children:hover > a::after {
        transform: rotate(225deg) !important;
    }
}

/* ===== BODY LOCK khi menu mở ===== */
body.menu-open {
    overflow: hidden !important;
}

/* ===== RESPONSIVE MOBILE < 768px ===== */
@media (max-width: 768px) {
    .header-container {
        min-height: 70px !important;
        padding: 0 20px !important;
        gap: 16px !important;
    }
    
    .custom-logo {
        max-height: 50px !important;
    }
    
    .logo-icon {
        width: 44px !important;
        height: 44px !important;
        font-size: 20px !important;
    }
    
    .logo-text {
        font-size: 18px !important;
    }
    
    .mobile-menu-toggle {
        display: block !important;
    }
    
    .header-nav {
        position: fixed !important;
        top: 70px !important;
        left: 0 !important;
        right: 0 !important;
        bottom: 0 !important;
        background: white !important;
        z-index: 999 !important;
        
        display: none !important;
        flex-direction: column !important;
        align-items: stretch !important;
        gap: 0 !important;
        flex-wrap: nowrap !important;
        
        padding: 0 !important;
        overflow-y: auto !important;
        overflow-x: hidden !important;
        -webkit-overflow-scrolling: touch !important;
        
        opacity: 0;
        transform: translateY(-20px);
        transition: all 0.3s ease;
    }
    
    .header-nav.active {
        display: flex !important;
        opacity: 1 !important;
        transform: translateY(0) !important;
    }
    
    .main-menu {
        flex-direction: column !important;
        gap: 0 !important;
        width: 100% !important;
        flex-wrap: nowrap !important;
        padding: 24px 20px !important;
    }
    
    .main-menu > li {
        width: 100% !important;
        border-bottom: 1px solid #F3F4F6 !important;
        opacity: 0;
    }
    
    .header-nav.active .main-menu > li {
        animation: slideInLeft 0.3s ease forwards;
    }
    
    .header-nav.active .main-menu > li:nth-child(1) { animation-delay: 0.05s; }
    .header-nav.active .main-menu > li:nth-child(2) { animation-delay: 0.1s; }
    .header-nav.active .main-menu > li:nth-child(3) { animation-delay: 0.15s; }
    .header-nav.active .main-menu > li:nth-child(4) { animation-delay: 0.2s; }
    .header-nav.active .main-menu > li:nth-child(5) { animation-delay: 0.25s; }
    .header-nav.active .main-menu > li:nth-child(6) { animation-delay: 0.3s; }
    .header-nav.active .main-menu > li:nth-child(7) { animation-delay: 0.35s; }
    
    @keyframes slideInLeft {
        from {
            opacity: 0;
            transform: translateX(-20px);
        }
        to {
            opacity: 1;
            transform: translateX(0);
        }
    }
    
    .main-menu > li:last-child {
        border-bottom: none !important;
    }
    
    .main-menu > li > a {
        width: 100% !important;
        padding: 16px 0 !important;
        border-radius: 0 !important;
        font-size: 16px !important;
        display: flex !important;
        justify-content: space-between !important;
        align-items: center !important;
    }
    
    .main-menu > li > a:hover {
        background: transparent !important;
        color: #f97316 !important;
    }
    
    .sub-menu {
        position: static !important;
        box-shadow: none !important;
        border: none !important;
        background: #FAFBFC !important;
        border-radius: 8px !important;
        margin: 8px 0 12px 0 !important;
        padding: 8px 0 !important;
        display: none !important;
    }
    
    .menu-item-has-children:hover > .sub-menu {
        display: none !important;
    }
    
    .menu-item-has-children.active > .sub-menu {
        display: block !important;
        animation: expandDown 0.3s ease;
    }
    
    @keyframes expandDown {
        from {
            max-height: 0;
            opacity: 0;
        }
        to {
            max-height: 500px;
            opacity: 1;
        }
    }
    
    .sub-menu li {
        border: none !important;
    }
    
    .sub-menu li a {
        padding: 12px 20px !important;
        border-radius: 6px !important;
        font-size: 15px !important;
    }
    
    .header-auth {
        flex-direction: column !important;
        gap: 12px !important;
        width: 100% !important;
        margin: 0 !important;
        padding: 24px 20px !important;
        border-top: 2px solid #F3F4F6 !important;
        opacity: 0;
    }
    
    .header-nav.active .header-auth {
        animation: fadeInUp 0.3s ease 0.4s forwards;
    }
    
    @keyframes fadeInUp {
        from {
            opacity: 0;
            transform: translateY(10px);
        }
        to {
            opacity: 1;
            transform: translateY(0);
        }
    }
    
    .btn-login,
    .btn-register {
        width: 100% !important;
        text-align: center !important;
        padding: 14px 24px !important;
        font-size: 16px !important;
        font-weight: 700 !important;
    }
    
    body.menu-open::after {
        content: '';
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        bottom: 0;
        background: rgba(0, 0, 0, 0.4);
        z-index: 998;
        animation: fadeIn 0.3s ease;
    }
    
    @keyframes fadeIn {
        from { opacity: 0; }
        to { opacity: 1; }
    }
    
    .menu-item-has-children > a::after {
        transition: transform 0.3s ease !important;
    }
    
    .menu-item-has-children.active > a::after {
        transform: rotate(225deg) !important;
    }
    
    .header-nav::-webkit-scrollbar {
        width: 6px;
    }
    
    .header-nav::-webkit-scrollbar-track {
        background: #F9FAFB;
    }
    
    .header-nav::-webkit-scrollbar-thumb {
        background: #D1D5DB;
        border-radius: 3px;
    }
    
    .header-nav::-webkit-scrollbar-thumb:hover {
        background: #9CA3AF;
    }
    
    .header-nav {
        scrollbar-width: thin;
        scrollbar-color: #D1D5DB #F9FAFB;
    }
}

/* ===== MOBILE NHỎ < 480px ===== */
@media (max-width: 480px) {
    .header-container {
        padding: 0 16px !important;
    }
    
    .custom-logo {
        max-height: 45px !important;
    }
    
    .logo-icon {
        width: 40px !important;
        height: 40px !important;
        font-size: 18px !important;
    }
    
    .logo-text {
        font-size: 16px !important;
    }
    
    .main-menu,
    .header-auth {
        padding-left: 16px !important;
        padding-right: 16px !important;
    }
}

/* ============================================
   FOOTER 4 CỘT - BỔ SUNG CSS
   Thêm vào CUỐI style.css
   Tận dụng CSS footer cũ, chỉ thêm phần thiếu
   ============================================ */

/* ===== LOGO FOOTER ===== */
.footer-logo {
    max-width: 180px;
    height: auto;
    margin-bottom: 20px;
    display: block;
}

/* ===== CONTACT INFO ===== */
.footer-contact {
    margin-top: 20px;
}

.footer-contact p {
    margin: 0 0 10px 0;
    font-size: 0.9375rem;
    line-height: 1.6;
    color: #D1D5DB;
}

.footer-contact strong {
    color: white;
    font-weight: 600;
}

/* ===== FOOTER GRID - Sửa lại 4 cột ===== */
.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1fr !important; /* 4 cột: Logo rộng hơn */
    gap: 60px;
    max-width: 1500px;
    margin: 0 auto 48px;
}

/* ===== SOCIAL GRID - 2x2 ===== */
.footer-social-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
}

.social-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    background: rgba(255,255,255,0.1);
    border-radius: 8px;
    text-decoration: none;
    transition: all 0.3s;
}

.social-item:hover {
    background: rgba(255,255,255,0.15);
    transform: translateX(4px);
}

.social-item img {
    width: 24px;
    height: 24px;
    flex-shrink: 0;
}

.social-item span {
    color: #D1D5DB;
    font-size: 0.875rem;
    font-weight: 500;
}

/* ===== FOOTER BOTTOM - Căn giữa ===== */
.footer-bottom-inner {
    max-width: 1500px;
    margin: 0 auto;
    padding: 0 32px;
    display: flex;
    justify-content: center !important; /* Căn giữa */
    align-items: center;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
    .footer-grid {
        grid-template-columns: 1fr 1fr !important; /* 2 cột */
        gap: 40px;
    }
    
    .footer-social-grid {
        grid-template-columns: repeat(4, 1fr); /* 4 cột ngang */
    }
}

@media (max-width: 768px) {
    .footer-grid {
        grid-template-columns: 1fr !important; /* 1 cột */
        gap: 32px;
    }
    
    .footer-logo {
        max-width: 150px;
    }
    
    .footer-social-grid {
        grid-template-columns: repeat(2, 1fr); /* Giữ 2x2 */
    }
    
    .footer-bottom-inner {
        padding: 0 20px;
    }
}

@media (max-width: 480px) {
    .footer-social-grid {
        grid-template-columns: 1fr; /* 1 cột mobile nhỏ */
    }
    
    .social-item {
        justify-content: flex-start;
    }
}