:root {
    --primary-color: #1a365d;
    --primary-light: #2c5282;
    --primary-dark: #0d1f3c;
    --danger-color: #e53e3e;
    --danger-light: #fc8181;
    --warning-color: #dd6b20;
    --success-color: #38a169;
    --bg-light: #f7fafc;
    --bg-white: #ffffff;
    --text-primary: #1a202c;
    --text-secondary: #4a5568;
    --text-muted: #718096;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-light);
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: var(--primary-light);
}

img {
    max-width: 100%;
    height: auto;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--bg-white);
    box-shadow: var(--shadow-md);
    z-index: 1000;
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 20px;
    font-weight: 700;
    color: var(--primary-color);
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 30px;
    list-style: none;
}

.nav-menu a {
    color: var(--text-secondary);
    font-weight: 500;
    padding: 8px 0;
    position: relative;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--primary-color);
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: var(--transition);
}

.nav-menu a:hover::after,
.nav-menu a.active::after {
    width: 100%;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 24px;
    font-size: 14px;
    font-weight: 600;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: white;
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-color));
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-danger {
    background: linear-gradient(135deg, var(--danger-color), #c53030);
    color: white;
}

.btn-danger:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
}

.btn-outline:hover {
    background: var(--primary-color);
    color: white;
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 24px;
    color: var(--primary-color);
    cursor: pointer;
}

.hero {
    margin-top: 70px;
    position: relative;
    height: 400px;
    overflow: hidden;
}

.hero-slider {
    position: relative;
    height: 100%;
}

.hero-slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    transition: opacity 0.8s ease;
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary-color) 50%, var(--primary-light) 100%);
}

.hero-slide.active {
    opacity: 1;
}

.hero-content {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
    color: white;
    z-index: 2;
}

.hero-title {
    font-size: 42px;
    font-weight: 700;
    margin-bottom: 16px;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.hero-subtitle {
    font-size: 20px;
    opacity: 0.9;
    margin-bottom: 30px;
}

.hero-dots {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 10px;
    z-index: 3;
}

.hero-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.4);
    cursor: pointer;
    transition: var(--transition);
}

.hero-dot.active {
    background: white;
    transform: scale(1.2);
}

.section {
    padding: 60px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 40px;
}

.section-title {
    font-size: 32px;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 12px;
}

.section-subtitle {
    font-size: 16px;
    color: var(--text-muted);
}

.fraud-types-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.fraud-card {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    padding: 30px 24px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    cursor: pointer;
}

.fraud-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.fraud-icon {
    width: 70px;
    height: 70px;
    margin: 0 auto 20px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 28px;
}

.fraud-card-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 10px;
}

.fraud-card-desc {
    font-size: 14px;
    color: var(--text-muted);
    line-height: 1.5;
}

.warnings-section {
    background: var(--bg-white);
}

.warnings-container {
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 30px;
}

.warnings-sidebar {
    background: linear-gradient(180deg, var(--danger-color), #c53030);
    border-radius: var(--radius-lg);
    padding: 30px;
    color: white;
}

.warnings-sidebar-title {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 16px;
}

.warnings-sidebar-desc {
    font-size: 14px;
    opacity: 0.9;
    line-height: 1.6;
}

.warnings-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.warning-item {
    background: var(--bg-light);
    border-radius: var(--radius-md);
    padding: 20px;
    border-left: 4px solid var(--danger-color);
    transition: var(--transition);
    cursor: pointer;
}

.warning-item:hover {
    background: var(--bg-white);
    box-shadow: var(--shadow-md);
}

.warning-item-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 10px;
}

.warning-level {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
}

.level-low {
    background: #c6f6d5;
    color: #22543d;
}

.level-medium {
    background: #feebc8;
    color: #744210;
}

.level-high {
    background: #fed7d7;
    color: #742a2a;
}

.level-critical {
    background: var(--danger-color);
    color: white;
}

.warning-date {
    font-size: 12px;
    color: var(--text-muted);
}

.warning-title {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
    line-height: 1.4;
}

.warning-excerpt {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.quick-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.quick-link-card {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    padding: 40px 30px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    cursor: pointer;
}

.quick-link-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.quick-link-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    background: var(--bg-light);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 36px;
    color: var(--primary-color);
    transition: var(--transition);
}

.quick-link-card:hover .quick-link-icon {
    background: var(--primary-color);
    color: white;
}

.quick-link-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.quick-link-desc {
    font-size: 14px;
    color: var(--text-muted);
}

.footer {
    background: var(--primary-dark);
    color: white;
    padding: 50px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand {
    max-width: 300px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 16px;
}

.footer-desc {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.6;
}

.footer-title {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 20px;
}

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

.footer-links li {
    margin-bottom: 12px;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    font-size: 14px;
}

.footer-links a:hover {
    color: white;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 30px;
    text-align: center;
}

.footer-copyright {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.6);
    margin-bottom: 10px;
}

.footer-icp {
    font-size: 12px;
    color: rgba(255, 255, 255, 0.5);
}

.footer-icp a {
    color: rgba(255, 255, 255, 0.5);
}

.detail-page {
    margin-top: 70px;
    padding: 40px 0;
}

.detail-header {
    margin-bottom: 30px;
}

.detail-title {
    font-size: 28px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 16px;
}

.detail-meta {
    display: flex;
    align-items: center;
    gap: 20px;
    color: var(--text-muted);
    font-size: 14px;
}

.detail-content {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    padding: 40px;
    box-shadow: var(--shadow-sm);
}

.detail-content p {
    margin-bottom: 16px;
    line-height: 1.8;
}

.detail-content h3 {
    font-size: 20px;
    font-weight: 600;
    color: var(--primary-color);
    margin: 30px 0 16px;
}

.detail-content ul {
    margin-left: 20px;
    margin-bottom: 16px;
}

.detail-content li {
    margin-bottom: 8px;
    line-height: 1.6;
}

.quiz-page {
    margin-top: 70px;
    padding: 40px 0;
    min-height: calc(100vh - 70px);
}

.quiz-container {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    margin-bottom: 30px;
}

.quiz-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 30px;
    background: var(--bg-light);
    border-bottom: 1px solid var(--border-color);
}

.quiz-title {
    font-size: 24px;
    font-weight: 600;
    color: var(--text-primary);
}

.quiz-info {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 15px 30px;
    background: rgba(26, 54, 93, 0.05);
}

.exam-type {
    padding: 6px 14px;
    background: var(--primary-color);
    color: white;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 500;
}

.exam-status {
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 500;
}

.exam-status.status-active {
    background: #c6f6d5;
    color: #22543d;
}

.exam-status.status-pending {
    background: #feebc8;
    color: #744210;
}

.exam-status.status-ended {
    background: #e2e8f0;
    color: #4a5568;
}

.exam-status.status-disabled {
    background: #fed7d7;
    color: #742a2a;
}

.quiz-iframe {
    width: 100%;
    height: calc(100vh - 250px);
    border: none;
}

.page-header {
    text-align: center;
    margin-bottom: 40px;
}

.page-title {
    font-size: 32px;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 12px;
}

.page-subtitle {
    font-size: 16px;
    color: var(--text-muted);
}

.exam-filters {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 30px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.filter-group {
    display: flex;
    align-items: center;
    gap: 10px;
}

.filter-group label {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-secondary);
}

.filter-group select {
    padding: 10px 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 14px;
    background: var(--bg-white);
    cursor: pointer;
    transition: var(--transition);
}

.filter-group select:focus {
    outline: none;
    border-color: var(--primary-color);
}

.exam-list {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 24px;
    width: 100%;
}

.exam-card {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    padding: 24px;
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.exam-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.exam-card-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    margin-bottom: 12px;
}

.exam-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    line-height: 1.4;
}

.exam-status-badge {
    padding: 4px 10px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 500;
}

.exam-status-badge.status-active {
    background: #c6f6d5;
    color: #22543d;
}

.exam-status-badge.status-pending {
    background: #feebc8;
    color: #744210;
}

.exam-status-badge.status-ended {
    background: #e2e8f0;
    color: #4a5568;
}

.exam-status-badge.status-disabled {
    background: #fed7d7;
    color: #742a2a;
}

.exam-type-tag {
    display: inline-block;
    padding: 4px 12px;
    background: rgba(26, 54, 93, 0.1);
    color: var(--primary-color);
    border-radius: 12px;
    font-size: 12px;
    font-weight: 500;
    margin-bottom: 12px;
}

.exam-description {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.5;
    margin-bottom: 16px;
}

.exam-meta {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-bottom: 20px;
}

.meta-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 13px;
    color: var(--text-muted);
}

.exam-actions {
    display: flex;
    gap: 10px;
}

.exam-actions .btn {
    flex: 1;
    justify-content: center;
}

.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--text-muted);
}

.empty-state svg {
    margin-bottom: 20px;
    opacity: 0.5;
}

.empty-state h3 {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

@media (max-width: 1199px) {
    .fraud-types-grid {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
    
    .exam-list {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (max-width: 991px) {
    .fraud-types-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
    
    .exam-list {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
    
    .warnings-container {
        grid-template-columns: 1fr;
    }
    
    .warnings-sidebar {
        display: none;
    }
    
    .quick-links {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-content {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 767px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--bg-white);
        flex-direction: column;
        padding: 20px;
        gap: 0;
        box-shadow: var(--shadow-lg);
    }
    
    .nav-menu.active {
        display: flex;
    }
    
    .nav-menu li {
        width: 100%;
    }
    
    .nav-menu a {
        display: block;
        padding: 12px 0;
        border-bottom: 1px solid var(--border-color);
    }
    
    .mobile-menu-btn {
        display: block;
    }
    
    .header-inner .btn {
        display: none;
    }
    
    .hero {
        height: 300px;
    }
    
    .hero-title {
        font-size: 28px;
    }
    
    .hero-subtitle {
        font-size: 16px;
    }
    
    .section {
        padding: 40px 0;
    }
    
    .section-title {
        font-size: 24px;
    }
    
    .fraud-types-grid {
        grid-template-columns: 1fr;
    }
    
    .quick-links {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
    
    .detail-content {
        padding: 24px;
    }
    
    .exam-list {
        grid-template-columns: minmax(0, 1fr);
        gap: 16px;
    }
    
    .exam-card {
        padding: 16px;
    }
    
    .exam-card-header {
        flex-direction: column;
        gap: 10px;
    }
    
    .exam-title {
        font-size: 16px;
    }
    
    .exam-meta {
        flex-direction: row;
        flex-wrap: wrap;
        gap: 15px;
        margin-bottom: 16px;
    }
    
    .meta-item {
        font-size: 12px;
    }
    
    .exam-description {
        font-size: 13px;
        margin-bottom: 12px;
    }
    
    .exam-filters {
        flex-direction: column;
        align-items: stretch;
        gap: 12px;
    }
    
    .filter-group {
        justify-content: space-between;
    }
    
    .filter-group select {
        min-width: 150px;
    }
    
    .quiz-header {
        flex-direction: column;
        gap: 12px;
        text-align: center;
    }
    
    .quiz-info {
        flex-direction: column;
        gap: 10px;
        text-align: center;
    }
    
    .quiz-iframe {
        height: 400px;
    }
    
    .page-title {
        font-size: 24px;
    }
    
    .page-subtitle {
        font-size: 14px;
    }
}