/* =========================================
   1. CSS CỐT LÕI (BASE)
   ========================================= */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

:root {
    --primary-color: #0d6efd;
    --secondary-color: #0a58ca;
    --dark-color: #1e293b;
    --gray-light: #f8fafc;
    --gray-text: #64748b;
    --accent-color: #ff9800;
    --white: #ffffff;
    --radius: 12px;
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box; /* Cực kỳ quan trọng để padding không cộng dồn vào width */
    font-family: 'Inter', sans-serif;
}

/* KHẮC PHỤC LỖI TRÀN VIỀN NGANG (HORIZONTAL OVERFLOW) */
html, body {
    width: 100%;
    max-width: 100%;
    overflow-x: hidden !important; /* Ép buộc ẩn mọi thứ tràn sang 2 bên */
    position: relative;
    -webkit-text-size-adjust: 100%;
}

body {
    background-color: var(--gray-light);
    color: var(--dark-color);
    line-height: 1.6;
    word-break: break-word; /* Tránh chữ quá dài làm bể khung trên mobile */
}

a {
    text-decoration: none;
}

/* Đảm bảo ảnh/video trên các bài viết không bao giờ bị tràn khung */
img, video, iframe {
    max-width: 100%;
    height: auto;
}

/* ==========================================================================
   2. RE-DESIGN HEADER & MOBILE MENU (FIXED LAYOUT OVERFLOW)
   ========================================================================== */
.site-header {
    background: #ffffff !important;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
    position: fixed;
    top: 0;
    left: 0;
    right: 0; /* Khóa chặt 2 đầu trái phải thay vì chỉ dùng width: 100% */
    width: 100%;
    max-width: 100%;
    z-index: 1000;
    height: 70px;
    display: flex;
    align-items: center;
}

.nav-container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 24px;
    font-weight: 700;
    color: var(--primary-color, #0d6efd) !important;
    display: flex;
    align-items: center;
    gap: 8px;
    white-space: nowrap;
}

.nav-links.desktop-menu {
    display: flex;
    align-items: center;
}

.nav-links.desktop-menu a {
    color: var(--dark-color, #1e293b) !important;
    margin: 0 18px;
    font-weight: 600;
    font-size: 15px;
    position: relative;
    padding: 5px 0;
    transition: color 0.3s ease;
}

.nav-links.desktop-menu a:hover {
    color: var(--primary-color, #0d6efd) !important;
}

.auth-buttons.desktop-menu {
    display: flex;
    align-items: center;
    gap: 12px;
}

.btn-register, .btn-user-profile, .btn-logout {
    white-space: nowrap;
}

.btn-register {
    background: linear-gradient(135deg, var(--primary-color, #0d6efd) 0%, var(--secondary-color, #0a58ca) 100%) !important;
    border: none !important;
    color: #ffffff !important;
    padding: 10px 24px;
    border-radius: 8px;
    font-weight: 600;
    font-size: 14px;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    box-shadow: 0 4px 12px rgba(13, 110, 253, 0.2);
    transition: all 0.3s ease;
}

.btn-register:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 18px rgba(13, 110, 253, 0.35);
}

.btn-user-profile {
    background: rgba(13, 110, 253, 0.06) !important;
    border: 1px solid rgba(13, 110, 253, 0.2) !important;
    color: var(--primary-color, #0d6efd) !important;
    padding: 10px 20px;
    border-radius: 8px;
    font-weight: 600;
    font-size: 14px;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    transition: all 0.3s ease;
}

.btn-user-profile:hover {
    background: var(--primary-color, #0d6efd) !important;
    color: #ffffff !important;
}

.btn-logout {
    background: linear-gradient(135deg, #dc3545 0%, #b21f2d 100%) !important;
    border: none !important;
    color: #ffffff !important;
    padding: 10px 20px;
    border-radius: 8px;
    font-weight: 600;
    font-size: 14px;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    box-shadow: 0 4px 12px rgba(220, 53, 69, 0.15);
    transition: all 0.3s ease;
}

.btn-logout:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 18px rgba(220, 53, 69, 0.3);
}

.mobile-only {
    display: none;
    background: #f1f5f9;
    border: none;
    width: 42px;
    height: 42px;
    border-radius: 8px;
    font-size: 20px;
    color: var(--primary-color, #0d6efd);
    cursor: pointer;
    align-items: center;
    justify-content: center;
}

/* Thêm đoạn này để ẩn Menu Mobile trên giao diện máy tính */
.mobile-menu-overlay {
    display: none;
}

/* ==========================================================================
   XỬ LÝ ĐÁP ỨNG DI ĐỘNG CHUẨN (ẨN TUYỆT ĐỐI KHÔNG GÂY TRÀN)
   ========================================================================== */
@media (max-width: 991px) {
    .desktop-menu {
        display: none !important;
    }
    
    .mobile-only {
        display: flex;
    }

    .mobile-menu-overlay {
        display: block;
        position: fixed;
        top: 70px;
        right: 0;
        width: 100%; /* KHẮC PHỤC: Đổi 100vw thành 100% để không tính thanh cuộn */
        max-width: 100%;
        height: calc(100vh - 70px);
        background: #ffffff;
        z-index: 999;
        visibility: hidden;
        opacity: 0;
        transform: translateX(100%);
        transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
        padding: 40px 24px;
        overflow-y: auto;
    }

    .mobile-menu-overlay.active {
        visibility: visible;
        opacity: 1;
        transform: translateX(0);
    }

    .mobile-menu-content {
        display: flex;
        flex-direction: column;
        gap: 8px;
    }

    .mobile-menu-content > a {
        display: block;
        padding: 16px;
        color: var(--dark-color, #1e293b) !important;
        font-size: 17px;
        font-weight: 600;
        border-bottom: 1px solid #f1f5f9;
        text-align: left;
    }

    .mobile-menu-content > a:active {
        color: var(--primary-color, #0d6efd) !important;
        background: #f8fafc;
    }

    .mobile-auth {
        margin-top: 24px;
        padding: 0 16px;
    }
    
    .mobile-auth .btn-register {
        width: 100%;
        padding: 14px;
        justify-content: center;
        font-size: 16px;
    }

    .mobile-user-box {
        display: flex;
        flex-direction: column;
        align-items: center;
        width: 100%;
    }

    .mobile-phone-display {
        font-size: 18px;
        font-weight: 700;
        color: var(--primary-color, #0d6efd);
        margin-bottom: 10px;
    }
}

/* ==========================================================================
   CSS FOOTER (CHÂN TRANG CHUYÊN NGHIỆP 4 CỘT)
   ========================================================================== */
.site-footer {
    background: #0f172a; 
    color: #94a3b8;
    padding: 70px 20px 20px 20px;
    margin-top: 80px;
    border-top: 1px solid #1e293b;
    font-size: 15px;
    width: 100%;
    overflow: hidden; /* Cắt phần dư nếu có */
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    /* KHẮC PHỤC TRÀN GRID: Dùng min(100%, 260px) để tự động thu nhỏ nếu màn hình điện thoại bé hơn 260px */
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 260px), 1fr));
    gap: 40px;
}

.footer-logo {
    font-size: 26px;
    font-weight: 700;
    color: var(--white);
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 15px;
}

.footer-logo i {
    color: var(--primary-color);
}

.footer-desc {
    line-height: 1.7;
    margin-bottom: 20px;
}

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

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background: rgba(255, 255, 255, 0.05);
    color: var(--white);
    border-radius: 50%;
    transition: all 0.3s ease;
}

.social-links a:hover {
    background: var(--primary-color);
    transform: translateY(-3px);
}

.footer-col h4 {
    color: var(--white);
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 25px;
    position: relative;
    padding-bottom: 10px;
}

.footer-col h4::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 40px;
    height: 3px;
    background: var(--primary-color);
    border-radius: 2px;
}

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

.footer-links li {
    margin-bottom: 15px;
}

.footer-links a {
    color: #cbd5e1;
    display: flex;
    align-items: center;
    gap: 8px;
}

.footer-links a i {
    font-size: 12px;
    color: var(--primary-color);
    transition: transform 0.3s ease;
}

.footer-links a:hover {
    color: var(--primary-color);
}

.footer-links a:hover i {
    transform: translateX(4px);
}

.contact-info {
    list-style: none;
}

.contact-info li {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    margin-bottom: 18px;
    line-height: 1.6;
}

.contact-info i {
    color: var(--primary-color);
    font-size: 16px;
    margin-top: 4px;
}

.contact-info strong {
    color: #e2e8f0;
}

.footer-bottom {
    margin-top: 60px;
    border-top: 1px solid #1e293b;
    padding-top: 25px;
}

.footer-bottom-inner {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 15px;
}

.footer-bottom p {
    color: #64748b;
    margin: 0;
}

.footer-bottom a {
    color: var(--primary-color);
    font-weight: 600;
}

.payment-methods {
    display: flex;
    gap: 15px;
    font-size: 24px;
    color: #64748b;
}

.payment-methods i:hover {
    color: var(--white);
    cursor: pointer;
}

@media (max-width: 768px) {
    .footer-container {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    .footer-bottom-inner {
        flex-direction: column;
        text-align: center;
    }
}

/* ========================================================= */
/* CSS NÂNG CẤP DÀNH RIÊNG CHO TRANG CHỦ MỚI                 */
/* ========================================================= */
:root {
    --primary: #0d6efd;
    --primary-hover: #0b5ed7;
    --dark: #0f172a;
    --text-main: #334155;
    --text-muted: #64748b;
    --bg-light: #f8fafc;
    --success: #10b981;
}

body {
    font-family: 'Inter', sans-serif;
    color: var(--text-main);
    line-height: 1.6;
    background: #fff;
}

/* HERO SECTION */
.hero-enhanced {
    background: linear-gradient(135deg, #f0f7ff 0%, #ffffff 100%);
    padding: 80px 20px 60px;
    text-align: center;
    border-bottom: 1px solid #e2e8f0;
}

.hero-content {
    max-width: 900px;
    margin: 0 auto;
}

.hero-content .badge {
    background: rgba(13, 110, 253, 0.1);
    color: var(--primary);
    padding: 6px 16px;
    border-radius: 50px;
    font-weight: 600;
    font-size: 14px;
    display: inline-block;
    margin-bottom: 20px;
    border: 1px solid rgba(13, 110, 253, 0.2);
}

.hero-content h1 {
    font-size: 46px;
    color: var(--dark);
    font-weight: 800;
    line-height: 1.3;
    margin-bottom: 20px;
    letter-spacing: -1px;
}

.hero-content h1 .highlight {
    color: var(--primary);
}

.hero-content p {
    font-size: 18px;
    color: var(--text-muted);
    margin-bottom: 35px;
    max-width: 750px;
    margin-inline: auto;
}

.hero-actions {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin-bottom: 40px;
    flex-wrap: wrap;
}

.btn-cta {
    background: var(--primary);
    color: #fff;
    padding: 15px 32px;
    border-radius: 8px;
    font-weight: 700;
    font-size: 16px;
    text-decoration: none;
    transition: 0.3s;
    box-shadow: 0 4px 15px rgba(13, 110, 253, 0.3);
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.btn-cta:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(13, 110, 253, 0.4);
}

.btn-outline {
    background: #fff;
    color: var(--dark);
    padding: 15px 32px;
    border-radius: 8px;
    font-weight: 700;
    font-size: 16px;
    text-decoration: none;
    transition: 0.3s;
    border: 1px solid #cbd5e1;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.btn-outline:hover {
    background: #f1f5f9;
    border-color: #94a3b8;
}

.trust-indicators {
    display: flex;
    justify-content: center;
    gap: 30px;
    flex-wrap: wrap;
    font-size: 15px;
    font-weight: 600;
    color: var(--dark);
}

.trust-indicators span i {
    color: var(--success);
    margin-right: 6px;
    font-size: 18px;
}

/* VÌ SAO CHỌN CHÚNG TÔI (FEATURES) */
.features-section {
    padding: 80px 20px;
    background: #fff;
}

.section-header {
    text-align: center;
    margin-bottom: 50px;
}

.section-header h2 {
    font-size: 32px;
    color: var(--dark);
    font-weight: 800;
    margin-bottom: 15px;
}

.section-header p {
    font-size: 16px;
    color: var(--text-muted);
    max-width: 650px;
    margin: 0 auto;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    max-width: 1200px;
    margin: 0 auto;
}

.feature-card {
    background: #fff;
    padding: 35px 25px;
    border-radius: 16px;
    border: 1px solid #e2e8f0;
    transition: 0.3s;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.02);
    text-align: left;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.08);
    border-color: #bae6fd;
}

.feature-icon {
    width: 60px;
    height: 60px;
    background: rgba(13, 110, 253, 0.1);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    font-size: 28px;
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 20px;
    color: var(--dark);
    margin-bottom: 12px;
    font-weight: 700;
}

.feature-card p {
    font-size: 15px;
    color: var(--text-muted);
    line-height: 1.6;
    margin: 0;
}

/* LỢI ÍCH (BENEFITS) */
.benefits-section {
    padding: 80px 20px;
    background: var(--bg-light);
}

.benefits-wrapper {
    max-width: 1100px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 40px;
}

.benefit-row {
    display: flex;
    align-items: center;
    gap: 40px;
    background: #fff;
    padding: 40px;
    border-radius: 16px;
    border: 1px solid #e2e8f0;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.03);
}

.benefit-row:nth-child(even) {
    flex-direction: row-reverse;
}

.benefit-content {
    flex: 1;
}

.benefit-content h3 {
    font-size: 24px;
    color: var(--dark);
    font-weight: 800;
    margin-bottom: 15px;
}

.benefit-content p {
    font-size: 16px;
    color: var(--text-muted);
    margin-bottom: 20px;
}

.benefit-content ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.benefit-content ul li {
    font-size: 15.5px;
    color: var(--dark);
    margin-bottom: 10px;
    display: flex;
    align-items: flex-start;
    gap: 10px;
    font-weight: 500;
}

.benefit-content ul li i {
    color: var(--success);
    margin-top: 4px;
}

.benefit-visual {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
}

.benefit-visual .visual-box {
    width: 100%;
    max-width: 350px;
    aspect-ratio: 4/3;
    background: linear-gradient(135deg, #e0f2fe 0%, #bae6fd 100%);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 60px;
    color: var(--primary);
    box-shadow: 0 10px 25px rgba(13, 110, 253, 0.15);
}

/* THỐNG KÊ (STATS) */
.stats-section {
    padding: 60px 20px;
    background: var(--dark);
    color: #fff;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 30px;
    max-width: 1000px;
    margin: 0 auto;
    text-align: center;
}

.stat-item h3 {
    font-size: 42px;
    color: #38bdf8;
    font-weight: 800;
    margin: 0 0 5px 0;
}

.stat-item p {
    font-size: 16px;
    color: #94a3b8;
    margin: 0;
    font-weight: 500;
}

/* FAQ SECTION */
.faq-section {
    padding: 80px 20px;
    background: #fff;
}

.faq-container {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    border: 1px solid #e2e8f0;
    border-radius: 10px;
    margin-bottom: 15px;
    overflow: hidden;
    transition: 0.3s;
}

.faq-item:hover {
    border-color: #cbd5e1;
}

.faq-question {
    padding: 20px;
    background: #f8fafc;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.faq-question h4 {
    margin: 0;
    font-size: 16px;
    color: var(--dark);
    font-weight: 600;
}

.faq-question i {
    color: var(--text-muted);
}

.faq-answer {
    padding: 0 20px 20px;
    background: #f8fafc;
    font-size: 15px;
    color: var(--text-muted);
    line-height: 1.6;
    border-top: 1px dashed #e2e8f0;
    margin-top: 5px;
}

@media (max-width: 768px) {
    .hero-content h1 {
        font-size: 32px;
    }

    .hero-actions {
        flex-direction: column;
    }

    .btn-cta,
    .btn-outline {
        width: 100%;
        justify-content: center;
    }

    .trust-indicators {
        flex-direction: column;
        gap: 15px;
        align-items: flex-start;
        margin: 0 auto;
        width: max-content;
    }

    .benefit-row,
    .benefit-row:nth-child(even) {
        flex-direction: column;
        padding: 25px;
    }
}

.visual-box {
    /* Giả sử bạn muốn khung này có kích thước cố định, hãy đặt ở đây */
    width: 100%; 
    max-width: 400px; /* Hoặc kích thước mong muốn của bạn */
    overflow: hidden;
}

.full-img {
    width: 100%;
    height: 100%;
    object-fit: cover; /* Giúp ảnh không bị méo, tự động cắt theo khung */
    display: block;    /* Loại bỏ khoảng hở thừa dưới ảnh */
}

/* ==========================================================================
   5. BỘ CSS CHUẨN MỰC CHO NỘI DUNG SEO (Áp dụng cho mọi trang)
   ========================================================================== */
.seo-article {
    max-width: 900px;
    margin: 60px auto;
    padding: 50px;
    background: var(--white);
    border-radius: var(--radius);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.03);
    font-size: 17px;
    line-height: 1.8;
    color: #334155;
}

.seo-article h2 {
    font-size: 28px;
    color: var(--primary-color);
    margin: 50px 0 20px 0;
    padding-bottom: 12px;
    border-bottom: 2px solid #e2e8f0;
    font-weight: 700;
    position: relative;
}

.seo-article h2::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 60px;
    height: 2px;
    background-color: var(--accent-color);
}

.seo-article h3 {
    font-size: 22px;
    color: var(--dark-color);
    margin: 35px 0 15px 0;
    font-weight: 700;
    padding-left: 15px;
    border-left: 4px solid var(--primary-color);
}

.seo-article h4 {
    font-size: 19px;
    color: var(--dark-color);
    margin: 25px 0 10px 0;
    font-weight: 600;
}

.seo-article p {
    margin-bottom: 20px;
}

.seo-article a {
    color: var(--primary-color);
    font-weight: 600;
    text-decoration: none;
    border-bottom: 1px dashed var(--primary-color);
    transition: all 0.3s ease;
}

.seo-article a:hover {
    color: var(--accent-color);
    border-bottom-color: var(--accent-color);
    background: rgba(255, 152, 0, 0.05);
}

.seo-article strong, .seo-article b {
    color: var(--dark-color);
    font-weight: 700;
}

.seo-article ul, .seo-article ol {
    margin-bottom: 25px;
    padding-left: 20px;
}

.seo-article li {
    margin-bottom: 12px;
    position: relative;
}

.seo-article ul {
    list-style-type: none;
}

.seo-article ul li::before {
    content: '✓';
    position: absolute;
    left: -25px;
    color: #10b981;
    font-weight: bold;
    font-size: 16px;
}

.seo-article ol {
    list-style-type: decimal;
}

.seo-article ol li::marker {
    color: var(--primary-color);
    font-weight: 700;
}

.seo-article figure {
    margin: 35px 0;
    text-align: center;
}

.seo-article img {
    max-width: 100%;
    height: auto;
    border-radius: 10px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.08);
    display: block;
    margin: 0 auto;
}

.seo-article figcaption {
    margin-top: 12px;
    font-size: 14.5px;
    color: #64748b;
    font-style: italic;
}

.seo-article table {
    width: 100%;
    border-collapse: collapse;
    margin: 30px 0;
    display: block;
    overflow-x: auto;
    max-width: 100%;
    -webkit-overflow-scrolling: touch;
    border-radius: 8px;
    border: 1px solid #e2e8f0;
}

.seo-article th, .seo-article td {
    padding: 16px;
    border: 1px solid #e2e8f0;
    text-align: left;
    min-width: 220px; 
    line-height: 1.6;
    vertical-align: top;
}

.seo-article th {
    background: var(--primary-color);
    color: var(--white);
    font-weight: 600;
}

.seo-article tr:nth-child(even) {
    background-color: #f8fafc;
}

.seo-article tr:hover td {
    background-color: #f1f5f9;
}

.seo-article table::-webkit-scrollbar {
    height: 8px;
}

.seo-article table::-webkit-scrollbar-track {
    background: #f1f5f9;
    border-radius: 0 0 8px 8px;
}

.seo-article table::-webkit-scrollbar-thumb {
    background: #cbd5e1;
    border-radius: 4px;
}

.seo-article table::-webkit-scrollbar-thumb:hover {
    background: #94a3b8;
}

.seo-article blockquote, .seo-quote {
    font-size: 18px;
    font-style: italic;
    color: var(--secondary-color);
    background: rgba(13, 110, 253, 0.05);
    padding: 25px 30px;
    border-left: 5px solid var(--primary-color);
    margin: 35px 0;
    border-radius: 0 8px 8px 0;
    position: relative;
}

.seo-alert-warning {
    background: rgba(245, 158, 11, 0.1);
    border: 1px solid #f59e0b;
    border-left: 5px solid #f59e0b;
    padding: 20px;
    border-radius: 8px;
    margin: 25px 0;
    color: #92400e;
}

.seo-alert-success {
    background: rgba(16, 185, 129, 0.1);
    border: 1px solid #10b981;
    border-left: 5px solid #10b981;
    padding: 20px;
    border-radius: 8px;
    margin: 25px 0;
    color: #065f46;
}

.table-of-contents {
    background: #f8fafc;
    padding: 30px;
    border-radius: 12px;
    border: 1px solid #e2e8f0;
    margin-bottom: 45px;
    box-shadow: inset 0 2px 4px rgba(0,0,0,0.02);
}

.table-of-contents h3 {
    margin-top: 0;
    margin-bottom: 20px;
    border: none;
    padding-left: 0;
    color: var(--primary-color);
    font-size: 20px;
}

.table-of-contents ul {
    list-style-type: none;
    padding-left: 0;
    margin-bottom: 0;
}

.table-of-contents ul li::before {
    display: none;
}

.table-of-contents ul li {
    margin-bottom: 12px;
    padding-left: 20px;
    position: relative;
}

.table-of-contents ul li::after {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--accent-color);
}

.table-of-contents a {
    color: var(--dark-color);
    border-bottom: none;
    font-weight: 500;
}

.table-of-contents a:hover {
    color: var(--primary-color);
    background: transparent;
    padding-left: 5px;
}

@media (max-width: 768px) {
    .seo-article { 
        padding: 25px 20px; 
        margin: 30px 15px; 
    }
    
    /* Thu nhỏ Text trên mobile để không bung giao diện */
    .hero h1 { font-size: 28px; }
    .hero p { font-size: 16px; }
    .hero-enhanced { padding-top: 100px; }

    .seo-article h2 { font-size: 24px; }
    .seo-article h3 { font-size: 20px; }
    
    .seo-quote, .seo-alert-warning, .seo-alert-success {
        padding: 15px 20px;
        font-size: 16px;
    }
}

/* =========================================
   6. BỔ SUNG GIAO DIỆN MỚI (HERO ENHANCED & FAQ)
   ========================================= */
.hero-enhanced {
    background: linear-gradient(135deg, #0f172a 0%, #1e3a8a 100%);
    padding: 120px 20px 80px 20px;
}

.hero-enhanced .badge {
    background: rgba(255, 255, 255, 0.1);
    color: #93c5fd;
    padding: 8px 16px;
    border-radius: 50px;
    font-size: 14px;
    font-weight: 600;
    letter-spacing: 1px;
    text-transform: uppercase;
    display: inline-block;
    margin-bottom: 20px;
    border: 1px solid rgba(147, 197, 253, 0.3);
}

.hero-enhanced .highlight {
    color: var(--accent-color);
}

.hero-actions {
    margin-top: 35px;
    display: flex;
    justify-content: center;
    gap: 15px;
    flex-wrap: wrap;
}

.btn-outline {
    background: transparent;
    color: var(--white);
    border: 2px solid rgba(255, 255, 255, 0.3);
    padding: 15px 30px;
    font-weight: 700;
    border-radius: 8px;
    transition: var(--transition);
    white-space: nowrap;
}

.btn-outline:hover {
    border-color: var(--white);
    background: rgba(255, 255, 255, 0.1);
}

.trust-indicators {
    margin-top: 40px;
    display: flex;
    justify-content: center;
    gap: 30px;
    color: #cbd5e1;
    font-size: 15px;
    flex-wrap: wrap;
}

.trust-indicators i {
    color: #4ade80;
    margin-right: 5px;
}

.icon-wrapper {
    width: 70px;
    height: 70px;
    background: rgba(13, 110, 253, 0.08);
    color: var(--primary-color);
    font-size: 30px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px auto;
}

.faq-section {
    background: var(--white);
    padding: 80px 20px;
}

.faq-container {
    max-width: 800px;
    margin: 0 auto;
}

.faq-title {
    text-align: center;
    font-size: 32px;
    color: var(--dark-color);
    margin-bottom: 10px;
}

.faq-subtitle {
    text-align: center;
    color: var(--gray-text);
    margin-bottom: 40px;
}

.faq-item {
    border: 1px solid #e2e8f0;
    border-radius: 10px;
    margin-bottom: 15px;
    overflow: hidden;
    transition: var(--transition);
}

.faq-item:hover {
    border-color: var(--primary-color);
    box-shadow: 0 4px 15px rgba(13, 110, 253, 0.05);
}

.faq-question {
    padding: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    background: var(--white);
}

.faq-question h4 {
    font-size: 17px;
    color: var(--dark-color);
    font-weight: 600;
}

.faq-question i {
    color: var(--primary-color);
    transition: transform 0.3s ease;
}

.faq-answer {
    padding: 0 20px;
    max-height: 0;
    overflow: hidden;
    background: #f8fafc;
    transition: max-height 0.3s ease, padding 0.3s ease;
}

.faq-answer p {
    color: #475569;
    font-size: 15px;
    line-height: 1.7;
    margin-bottom: 0;
}

.faq-item.active .faq-answer {
    padding: 20px;
    max-height: 300px; 
    border-top: 1px solid #e2e8f0;
}

.faq-item.active .faq-question i {
    transform: rotate(180deg);
}

@media (max-width: 768px) {
    .trust-indicators { gap: 15px; flex-direction: column; align-items: center; }
}

/* ==========================================================================
   7. CSS CHO TRANG ĐĂNG NHẬP / ĐĂNG KÝ (AUTH)
   ========================================================================== */
.auth-page-wrapper {
    min-height: calc(100vh - 100px);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 120px 20px 60px 20px;
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
}

.auth-box {
    background: var(--white);
    width: 100%;
    max-width: 480px;
    border-radius: 16px;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.05);
    padding: 40px;
    position: relative;
    overflow: hidden;
}

.auth-tabs {
    display: flex;
    margin-bottom: 30px;
    background: #f1f5f9;
    border-radius: 10px;
    padding: 5px;
}

.tab-btn {
    flex: 1;
    background: transparent;
    border: none;
    padding: 12px;
    font-size: 16px;
    font-weight: 600;
    color: var(--gray-text);
    cursor: pointer;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.tab-btn.active {
    background: var(--white);
    color: var(--primary-color);
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.auth-form-content {
    display: none;
    animation: fadeIn 0.4s ease;
}

.auth-form-content.active {
    display: block;
}

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

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--dark-color);
    font-size: 14.5px;
}

.input-with-icon {
    position: relative;
}

.input-with-icon input {
    width: 100%;
    padding: 14px 45px;
    border: 1px solid #cbd5e1;
    border-radius: 8px;
    font-size: 15px;
    outline: none;
    transition: all 0.3s ease;
    color: var(--dark-color);
}

.input-with-icon input:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(13, 110, 253, 0.1);
}

.input-icon {
    position: absolute;
    left: 15px;
    top: 50%;
    transform: translateY(-50%);
    color: #94a3b8;
}

.toggle-password {
    position: absolute;
    right: 15px;
    top: 50%;
    transform: translateY(-50%);
    color: #94a3b8;
    cursor: pointer;
    transition: color 0.3s;
}

.toggle-password:hover {
    color: var(--primary-color);
}

.role-selector {
    display: flex;
    gap: 15px;
}

.role-option {
    flex: 1;
    cursor: pointer;
}

.role-option input {
    display: none;
}

.role-card {
    border: 2px solid #cbd5e1;
    border-radius: 10px;
    padding: 15px 10px;
    text-align: center;
    transition: all 0.3s ease;
    color: var(--gray-text);
}

.role-card i {
    font-size: 24px;
    display: block;
    margin-bottom: 8px;
}

.role-card span {
    font-size: 14px;
    font-weight: 600;
}

.role-option input:checked + .role-card {
    border-color: var(--primary-color);
    background: rgba(13, 110, 253, 0.05);
    color: var(--primary-color);
}

.btn-auth-submit {
    width: 100%;
    background: var(--primary-color);
    color: var(--white);
    border: none;
    padding: 15px;
    font-size: 16px;
    font-weight: 700;
    border-radius: 8px;
    cursor: pointer;
    margin-top: 10px;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(13, 110, 253, 0.2);
}

.btn-auth-submit:hover {
    background: var(--secondary-color);
    transform: translateY(-2px);
}

.alert {
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 20px;
    font-size: 14.5px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.alert-danger {
    background: #fef2f2;
    color: #dc2626;
    border: 1px solid #f87171;
}

.alert-success {
    background: #ecfdf5;
    color: #059669;
    border: 1px solid #34d399;
}

@media (max-width: 480px) {
    .auth-box { padding: 30px 20px; }
    .role-selector { flex-direction: column; gap: 10px; }
}