/* ========================================
   优学智考官方网站样式
   响应式设计 | 移动优先 | SEO 友好
   ======================================== */

/* CSS Variables */
:root {
    --primary: #4F6EF7;
    --primary-dark: #3D56D4;
    --primary-light: #EEF0FF;
    --danger: #FF4757;
    --text: #1a1a2e;
    --text-secondary: #555;
    --text-muted: #888;
    --bg: #f8f9fc;
    --white: #ffffff;
    --border: #e8ecf1;
    --radius: 12px;
    --radius-lg: 20px;
    --shadow: 0 2px 16px rgba(0,0,0,.06);
    --max-width: 1200px;
    --transition: .25s ease;
}

/* Reset */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Helvetica Neue", sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--primary-dark); }

.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

.container.narrow { max-width: 800px; }

/* ===== Header / Navigation ===== */
.site-header {
    background: rgba(255,255,255,.92);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
}

.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 20px;
    font-weight: 700;
    color: var(--text) !important;
    letter-spacing: -.5px;
}

.logo-icon { font-size: 28px; }

.nav-links {
    display: flex;
    gap: 32px;
}

.nav-links a {
    color: var(--text-secondary);
    font-size: 15px;
    font-weight: 500;
    position: relative;
    padding: 4px 0;
}

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

.nav-links a.active::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary);
    border-radius: 1px;
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px 4px;
}

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

/* ===== Hero ===== */
.hero {
    padding: 80px 0 100px;
    background: linear-gradient(135deg, #f0f4ff 0%, #fff 50%, #f8f6ff 100%);
    overflow: hidden;
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-content h1 {
    font-size: 48px;
    font-weight: 800;
    line-height: 1.2;
    color: var(--text);
    letter-spacing: -1px;
    margin-bottom: 20px;
}

.hero-content h1 .highlight {
    background: linear-gradient(135deg, var(--primary), #8B5CF6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 18px;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 32px;
    max-width: 480px;
}

.hero-cta {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
    margin-bottom: 32px;
}

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

.hero-badges span {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: 20px;
    padding: 6px 16px;
    font-size: 14px;
    color: var(--text-secondary);
    font-weight: 500;
}

/* Hero mockup */
.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-mockup {
    perspective: 1000px;
}

.mockup-screen {
    width: 320px;
    background: var(--white);
    border-radius: 28px;
    box-shadow: 0 20px 60px rgba(79,110,247,.15), 0 4px 16px rgba(0,0,0,.08);
    overflow: hidden;
    transform: rotateY(-6deg) rotateX(3deg);
    border: 3px solid #e0e0e0;
}

.mockup-statusbar {
    height: 36px;
    background: #f0f0f0;
}

.mockup-content {
    padding: 20px;
}

.mockup-icon {
    font-size: 36px;
    margin-bottom: 8px;
}

.mockup-title {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 12px;
}

.mockup-question {
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 12px;
    line-height: 1.5;
}

.mockup-options { display: flex; flex-direction: column; gap: 8px; }

.mockup-opt {
    font-size: 13px;
    padding: 10px 14px;
    border-radius: 10px;
    background: var(--bg);
    color: var(--text-secondary);
    transition: var(--transition);
}

.mockup-opt.correct {
    background: #EEF7EE;
    color: #2E7D32;
    border: 1px solid #C8E6C9;
}

/* ===== Buttons ===== */
.btn-primary {
    display: inline-block;
    background: var(--primary);
    color: #fff !important;
    padding: 14px 36px;
    border-radius: var(--radius);
    font-weight: 600;
    font-size: 16px;
    transition: all var(--transition);
    border: none;
    cursor: pointer;
    text-align: center;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(79,110,247,.3);
}

.btn-outline {
    display: inline-block;
    background: var(--white);
    color: var(--primary) !important;
    padding: 14px 36px;
    border-radius: var(--radius);
    font-weight: 600;
    font-size: 16px;
    border: 2px solid var(--border);
    transition: all var(--transition);
}

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

/* ===== Stats Bar ===== */
.stats-bar {
    padding: 40px 0;
    margin-top: -30px;
    position: relative;
    z-index: 2;
}

.stats-bar .container {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0;
    background: var(--white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    padding: 32px 0;
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    border-right: 1px solid var(--border);
    padding: 0 24px;
}

.stat-item:last-child { border-right: none; }

.stat-number {
    font-size: 36px;
    font-weight: 800;
    color: var(--primary);
    line-height: 1;
}

.stat-label {
    font-size: 15px;
    color: var(--text-muted);
}

/* ===== Sections ===== */
.section {
    padding: 80px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 56px;
}

.section-header h2 {
    font-size: 36px;
    font-weight: 800;
    letter-spacing: -.5px;
    margin-bottom: 12px;
}

.section-desc {
    font-size: 17px;
    color: var(--text-muted);
    max-width: 500px;
    margin: 0 auto;
}

/* Page hero (sub pages) */
.page-hero {
    padding: 60px 0 40px;
    text-align: center;
    background: linear-gradient(135deg, #f0f4ff 0%, #fff 100%);
}

.page-hero h1 {
    font-size: 40px;
    font-weight: 800;
}

.page-subtitle {
    font-size: 17px;
    color: var(--text-muted);
    margin-top: 12px;
}

/* ===== Features Grid ===== */
.features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

.feature-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 32px 24px;
    transition: transform var(--transition), box-shadow var(--transition);
    border: 1px solid var(--border);
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow);
}

.feature-icon {
    font-size: 40px;
    margin-bottom: 16px;
}

.feature-card h3 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 8px;
}

.feature-card p {
    font-size: 14px;
    color: var(--text-muted);
    line-height: 1.7;
}

/* ===== Feature Detail Grid (features page) ===== */
.feature-detail-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px 60px;
}

.feature-detail h2 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 12px;
}

.feature-detail p {
    font-size: 16px;
    color: var(--text-secondary);
    line-height: 1.8;
}

/* ===== Workflow ===== */
.workflow-section { background: var(--white); }

.workflow-steps {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 40px;
}

.workflow-step {
    text-align: center;
    max-width: 240px;
}

.step-number {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: var(--primary);
    color: #fff;
    font-size: 24px;
    font-weight: 800;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 16px;
}

.workflow-step h3 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 8px;
}

.workflow-step p {
    font-size: 14px;
    color: var(--text-muted);
}

.workflow-arrow {
    font-size: 28px;
    color: var(--text-muted);
    flex-shrink: 0;
}

/* ===== Scenarios ===== */
.scenarios-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}

.scenario-item {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    text-align: center;
    font-size: 15px;
    font-weight: 600;
    color: var(--text-secondary);
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}

.scenario-item:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.scenario-icon { font-size: 32px; }

/* ===== CTA ===== */
.cta-section {
    text-align: center;
    background: linear-gradient(135deg, var(--primary), #6C5CE7);
    color: #fff;
    padding: 80px 0;
}

.cta-section h2 {
    font-size: 36px;
    font-weight: 800;
    margin-bottom: 12px;
}

.cta-section p {
    font-size: 17px;
    opacity: .9;
    margin-bottom: 32px;
}

.cta-section .btn-primary {
    background: #fff;
    color: var(--primary) !important;
}

.cta-section .btn-primary:hover {
    background: #f0f0f0;
}

/* ===== Footer ===== */
.site-footer {
    background: #1a1a2e;
    color: rgba(255,255,255,.7);
    padding: 56px 0 0;
    font-size: 14px;
}

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

.footer-grid h3 { color: #fff; font-size: 18px; margin-bottom: 16px; }
.footer-grid h4 { color: #fff; font-size: 15px; margin-bottom: 12px; }

.footer-grid p { line-height: 1.7; margin-bottom: 6px; }

.footer-links a,
.footer-legal a {
    display: block;
    color: rgba(255,255,255,.6);
    margin-bottom: 8px;
    transition: color var(--transition);
}

.footer-links a:hover,
.footer-legal a:hover { color: #fff; }

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,.1);
    padding: 20px 0;
    text-align: center;
    font-size: 13px;
}

.footer-bottom a { color: rgba(255,255,255,.5); }

/* ===== Contact ===== */
.contact-cards {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
    margin-bottom: 20px;
}

.contact-card {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 40px 32px;
    text-align: center;
}

.contact-icon { font-size: 48px; margin-bottom: 16px; }
.contact-card h3 { font-size: 20px; margin-bottom: 8px; }
.contact-card p { font-size: 15px; color: var(--text-secondary); }
.contact-hint { font-size: 13px !important; color: var(--text-muted) !important; margin-top: 4px; }

/* ===== FAQ ===== */
.faq-list { margin-top: 24px; }

.faq-item {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    margin-bottom: 12px;
    padding: 20px 24px;
}

.faq-item summary {
    font-weight: 600;
    cursor: pointer;
    font-size: 16px;
    list-style: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.faq-item summary::-webkit-details-marker { display: none; }

.faq-item summary::after {
    content: '+';
    font-size: 20px;
    color: var(--primary);
    transition: transform var(--transition);
}

.faq-item[open] summary::after {
    content: '−';
}

.faq-item p {
    padding-top: 12px;
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ===== About Page ===== */
.about-features {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-top: 24px;
}

.about-feat {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 28px 24px;
}

.about-feat h3 { font-size: 18px; margin-bottom: 8px; }
.about-feat p { font-size: 14px; color: var(--text-muted); line-height: 1.7; }

/* ===== Legal Content ===== */
.legal-content h2 {
    font-size: 22px;
    margin-top: 32px;
    margin-bottom: 12px;
}

.legal-content h2:first-of-type { margin-top: 0; }

.legal-content p {
    margin-bottom: 12px;
    color: var(--text-secondary);
    line-height: 1.8;
}

.legal-content ul {
    padding-left: 20px;
    margin-bottom: 12px;
}

.legal-content li {
    margin-bottom: 6px;
    color: var(--text-secondary);
}

/* ===== Article List ===== */
.article-grid {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.article-card {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    transition: transform var(--transition), box-shadow var(--transition);
}

.article-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.article-card-link {
    display: flex;
    align-items: stretch;
    color: inherit !important;
    text-decoration: none;
}

.article-cover {
    font-size: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 120px;
    flex-shrink: 0;
    background: var(--primary-light);
    border-radius: var(--radius-lg) 0 0 var(--radius-lg);
}

.article-card-body {
    padding: 24px;
    flex: 1;
    min-width: 0;
}

.article-meta {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 8px;
    font-size: 13px;
}

.article-category {
    background: var(--primary-light);
    color: var(--primary);
    padding: 2px 10px;
    border-radius: 12px;
    font-weight: 600;
    font-size: 12px;
}

.article-date {
    color: var(--text-muted);
}

.article-card-title {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 8px;
    line-height: 1.4;
}

.article-card-desc {
    font-size: 14px;
    color: var(--text-muted);
    line-height: 1.6;
    margin-bottom: 12px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.article-read-more {
    font-size: 14px;
    font-weight: 600;
    color: var(--primary);
}

/* ===== Article Detail ===== */
.article-detail .page-hero h1 {
    font-size: 32px;
    line-height: 1.3;
    margin-top: 12px;
}

.article-meta-top {
    justify-content: center;
    font-size: 14px;
}

.article-body {
    font-size: 16px;
}

.article-body h2 {
    font-size: 24px;
    font-weight: 700;
    margin: 36px 0 16px;
    color: var(--text);
    padding-bottom: 8px;
    border-bottom: 2px solid var(--primary-light);
}

.article-body h2:first-of-type {
    margin-top: 0;
}

.article-body h3 {
    font-size: 20px;
    font-weight: 700;
    margin: 24px 0 12px;
}

.article-body p {
    margin-bottom: 16px;
    color: var(--text-secondary);
    line-height: 1.9;
}

.article-body ul {
    padding-left: 24px;
    margin-bottom: 16px;
}

.article-body li {
    margin-bottom: 8px;
    color: var(--text-secondary);
    line-height: 1.8;
}

.article-body strong {
    color: var(--text);
}

/* Comparison Table */
.comparison-table {
    overflow-x: auto;
    margin-bottom: 20px;
}

.comparison-table table {
    width: 100%;
    border-collapse: collapse;
    font-size: 14px;
}

.comparison-table th {
    background: var(--primary);
    color: #fff;
    padding: 12px 16px;
    text-align: left;
    font-weight: 600;
}

.comparison-table th:first-child { border-radius: 8px 0 0 0; }
.comparison-table th:last-child { border-radius: 0 8px 0 0; }

.comparison-table td {
    padding: 12px 16px;
    border-bottom: 1px solid var(--border);
}

.comparison-table tr:nth-child(even) td {
    background: var(--bg);
}

/* Article CTA */
.article-cta {
    margin-top: 40px;
    padding: 32px;
    background: linear-gradient(135deg, var(--primary), #6C5CE7);
    border-radius: var(--radius-lg);
    text-align: center;
    color: #fff;
}

.article-cta p {
    color: rgba(255,255,255,.9) !important;
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 20px;
}

.article-cta .btn-primary {
    background: #fff;
    color: var(--primary) !important;
}

.article-cta .btn-primary:hover {
    background: #f0f0f0;
}

/* Article Nav */
.article-nav {
    margin-top: 40px;
    padding-top: 20px;
    border-top: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
}

/* ===== Question List ===== */
.question-grid {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.question-card {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    transition: transform var(--transition), box-shadow var(--transition);
}

.question-card:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow);
}

.question-card-link {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 16px 20px;
    color: inherit !important;
    text-decoration: none;
}

.question-type-badge {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    min-width: 52px;
    flex-shrink: 0;
}

.q-type-icon {
    font-size: 24px;
    color: var(--primary);
}

.q-type-label {
    font-size: 11px;
    color: var(--text-muted);
    font-weight: 600;
}

.question-card-body {
    flex: 1;
    min-width: 0;
}

.question-card-title {
    font-size: 16px;
    font-weight: 600;
    color: var(--text);
    line-height: 1.5;
    margin-bottom: 4px;
}

.question-bank-tag {
    font-size: 12px;
    color: var(--text-muted);
}

.question-card-arrow {
    font-size: 24px;
    color: var(--border);
    flex-shrink: 0;
}

/* ===== Pagination ===== */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 8px;
    margin-top: 40px;
    flex-wrap: wrap;
}

.page-btn, .page-num {
    display: inline-block;
    padding: 8px 18px;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    color: var(--text-secondary);
    background: var(--white);
    border: 1px solid var(--border);
    transition: all var(--transition);
}

.page-btn:hover, .page-num:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.page-num.active {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

.page-btn.disabled, .page-num.disabled {
    color: var(--border);
    cursor: not-allowed;
}

.page-ellipsis {
    padding: 8px 4px;
    color: var(--text-muted);
}

/* ===== Question Detail ===== */
.passage-block {
    background: var(--primary-light);
    border: 1px solid #dde0ff;
    border-radius: var(--radius);
    padding: 20px 24px;
    margin-bottom: 24px;
}

.passage-content {
    font-size: 15px;
    line-height: 2;
    color: var(--text-secondary);
}

.question-options {
    margin-bottom: 24px;
}

.option-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 18px;
    margin-bottom: 8px;
    background: var(--bg);
    border-radius: 10px;
    border: 1px solid var(--border);
    transition: var(--transition);
}

.option-item.correct {
    background: #EEF7EE;
    border-color: #C8E6C9;
}

.option-key {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: var(--white);
    border: 1px solid var(--border);
    font-size: 14px;
    font-weight: 700;
    color: var(--text-secondary);
    flex-shrink: 0;
}

.option-item.correct .option-key {
    background: #2E7D32;
    color: #fff;
    border-color: #2E7D32;
}

.option-content {
    flex: 1;
    font-size: 15px;
    color: var(--text-secondary);
}

.option-item.correct .option-content {
    color: #2E7D32;
    font-weight: 600;
}

.option-mark {
    color: #2E7D32;
    font-size: 18px;
    font-weight: 700;
    flex-shrink: 0;
}

/* 连线题 */
.match-options {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.match-column h3 {
    font-size: 16px;
    margin-bottom: 8px;
    color: var(--text);
}

.match-item {
    padding: 10px 14px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    margin-bottom: 6px;
    font-size: 14px;
}

/* 答案区域 */
.answer-block {
    background: #EEF7EE;
    border: 1px solid #C8E6C9;
    border-radius: var(--radius);
    padding: 16px 20px;
    margin-bottom: 24px;
    font-size: 16px;
    color: #2E7D32;
}

/* 解析区域 */
.analysis-block {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px 24px;
    font-size: 15px;
    line-height: 1.9;
    color: var(--text-secondary);
}

/* ===== 相关题目推荐 ===== */
.related-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
    margin-bottom: 24px;
}

.related-card {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 14px 16px;
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: 10px;
    color: var(--text) !important;
    text-decoration: none;
    transition: border-color var(--transition);
    overflow: hidden;
}

.related-card:hover {
    border-color: var(--primary);
}

.related-badge {
    display: inline-block;
    padding: 2px 8px;
    background: var(--primary-light);
    color: var(--primary);
    font-size: 12px;
    font-weight: 600;
    border-radius: 6px;
    flex-shrink: 0;
}

.related-title {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-secondary);
    line-height: 1.4;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* ===== 蜘蛛抓取区域（1px，仅搜索引擎可见） ===== */
.spider-links {
    position: fixed;
    left: 0;
    bottom: 0;
    width: 1px;
    height: 1px;
    overflow: hidden;
    font-size: 0;
    line-height: 0;
}

.spider-links a {
    color: transparent;
    font-size: 0;
    line-height: 0;
    display: inline;
}

/* ===== Animations ===== */
.fade-in {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity .6s ease, transform .6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ========================================
   RESPONSIVE - TABLET (<= 1024px)
   ======================================== */
@media (max-width: 1024px) {
    .hero .container {
        grid-template-columns: 1fr;
        gap: 48px;
        text-align: center;
    }

    .hero-content h1 { font-size: 38px; }
    .hero-subtitle { max-width: 100%; }
    .hero-cta { justify-content: center; }
    .hero-badges { justify-content: center; }

    .hero-visual { display: none; }

    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .scenarios-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .workflow-steps {
        flex-direction: column;
        gap: 20px;
    }

    .workflow-arrow {
        transform: rotate(90deg);
    }

    .feature-detail-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }

    .about-features {
        grid-template-columns: 1fr;
    }

    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 32px;
    }
}

/* ========================================
   RESPONSIVE - MOBILE (<= 768px)
   ======================================== */
@media (max-width: 768px) {
    html { font-size: 15px; }

    /* Mobile nav */
    .nav-links {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: var(--white);
        border-bottom: 1px solid var(--border);
        flex-direction: column;
        padding: 16px 20px;
        gap: 4px;
        box-shadow: var(--shadow);
    }

    .nav-links.open { display: flex; }

    .nav-links a {
        padding: 12px 0;
        font-size: 16px;
    }

    .nav-links a.active::after { display: none; }

    .mobile-menu-btn { display: flex; }

    /* Hero */
    .hero { padding: 48px 0 64px; }
    .hero-content h1 { font-size: 30px; }

    .hero-subtitle { font-size: 16px; }

    .btn-primary,
    .btn-outline {
        padding: 12px 24px;
        font-size: 15px;
    }

    /* Stats */
    .stats-bar .container {
        grid-template-columns: repeat(2, 1fr);
        padding: 24px 0;
    }

    .stat-item {
        border-right: 1px solid var(--border);
        border-bottom: 1px solid var(--border);
        padding: 16px;
    }

    .stat-item:nth-child(2) { border-right: none; }
    .stat-item:nth-child(3) { border-bottom: none; }
    .stat-item:nth-child(4) { border-bottom: none; }

    .stat-number { font-size: 28px; }

    /* Sections */
    .section { padding: 56px 0; }
    .section-header h2 { font-size: 28px; }
    .section-header { margin-bottom: 40px; }
    .page-hero h1 { font-size: 30px; }

    /* Features */
    .features-grid {
        grid-template-columns: 1fr;
        gap: 12px;
    }

    .feature-card { padding: 24px 20px; }

    /* Scenarios */
    .scenarios-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    /* Contact */
    .contact-cards {
        grid-template-columns: 1fr;
    }

    /* CTA */
    .cta-section h2 { font-size: 26px; }

    /* Footer */
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 24px;
    }
}

/* ========================================
   RESPONSIVE - SMALL MOBILE (<= 480px)
   ======================================== */
@media (max-width: 480px) {
    .hero-content h1 { font-size: 26px; }
    .section-header h2 { font-size: 24px; }
    .page-hero h1 { font-size: 26px; }

    .stat-number { font-size: 24px; }
    .stat-label { font-size: 13px; }

    .hero-cta { flex-direction: column; }
    .btn-primary, .btn-outline { width: 100%; }

    .scenarios-grid { grid-template-columns: 1fr 1fr; }
    .scenario-item { padding: 16px; font-size: 13px; }
    .scenario-icon { font-size: 26px; }

    .feature-detail h2 { font-size: 20px; }
    .feature-detail p { font-size: 15px; }

    /* Article cards on mobile */
    .article-card-link {
        flex-direction: column;
    }

    .article-cover {
        width: 100%;
        height: 100px;
        border-radius: var(--radius-lg) var(--radius-lg) 0 0;
        font-size: 40px;
    }

    .article-card-title { font-size: 18px; }
    .article-detail .page-hero h1 { font-size: 24px; }
    .article-body { font-size: 15px; }
    .article-body h2 { font-size: 20px; }
    .article-cta { padding: 24px 20px; }
    .article-cta p { font-size: 16px; }

    /* Question on mobile */
    .question-card-link { padding: 14px 16px; gap: 12px; }
    .question-card-title { font-size: 14px; }
    .option-item { padding: 12px 14px; }
    .match-options { grid-template-columns: 1fr; }
    .related-grid { grid-template-columns: 1fr; }
}