/* ===== CSS Variables & Reset ===== */
:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #8b5cf6;
    --accent: #a855f7;
    --bg: #0a0a0f;
    --bg-secondary: #111118;
    --bg-card: #16161f;
    --bg-card-hover: #1c1c28;
    --surface: #1e1e2a;
    --border: #2a2a3a;
    --border-light: #3a3a4a;
    --text: #e4e4e7;
    --text-secondary: #a1a1aa;
    --text-muted: #71717a;
    --white: #ffffff;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --gradient: linear-gradient(135deg, var(--primary), var(--secondary));
    --gradient-text: linear-gradient(135deg, #818cf8, #c084fc);
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
    --shadow: 0 4px 12px rgba(0,0,0,0.4);
    --shadow-lg: 0 12px 40px rgba(0,0,0,0.5);
    --shadow-glow: 0 0 40px rgba(99,102,241,0.15);
    --radius: 12px;
    --radius-lg: 20px;
    --radius-sm: 8px;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --container: 1200px;
    --header-height: 72px;
}

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

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.7;
    font-size: 16px;
    overflow-x: hidden;
}

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

a:hover {
    color: var(--accent);
}

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

ul { list-style: none; }

.container {
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== Header ===== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    z-index: 1000;
    background: rgba(10, 10, 15, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid transparent;
    transition: all var(--transition);
}

.header.scrolled {
    border-bottom-color: var(--border);
    background: rgba(10, 10, 15, 0.95);
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--white);
    font-size: 1.25rem;
    font-weight: 400;
    letter-spacing: -0.02em;
}

.logo:hover { color: var(--white); }

.logo strong {
    font-weight: 700;
    background: var(--gradient-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.logo-icon { display: flex; align-items: center; }

.nav {
    display: flex;
    align-items: center;
    gap: 4px;
}

.nav-link {
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    transition: all var(--transition);
}

.nav-link:hover,
.nav-link.active {
    color: var(--white);
    background: rgba(99, 102, 241, 0.1);
}

.nav-link.active {
    color: var(--primary-light);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text);
    border-radius: 2px;
    transition: all var(--transition);
}

/* ===== Hero ===== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: var(--header-height);
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    overflow: hidden;
}

.hero-grid {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(99, 102, 241, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(99, 102, 241, 0.03) 1px, transparent 1px);
    background-size: 60px 60px;
}

.hero-glow {
    position: absolute;
    top: 20%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 800px;
    height: 600px;
    background: radial-gradient(ellipse, rgba(99, 102, 241, 0.12) 0%, rgba(139, 92, 246, 0.06) 40%, transparent 70%);
    pointer-events: none;
}

.hero-content {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
    padding: 60px 0;
    position: relative;
    z-index: 1;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 20px;
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.2);
    border-radius: 100px;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--primary-light);
    margin-bottom: 32px;
}

.hero-title {
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -0.03em;
    color: var(--white);
    margin-bottom: 24px;
}

.gradient-text {
    background: var(--gradient-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    max-width: 640px;
    margin: 0 auto 40px;
    line-height: 1.8;
}

.hero-cta {
    display: flex;
    justify-content: center;
    gap: 16px;
    margin-bottom: 60px;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 32px;
    border-radius: var(--radius);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: all var(--transition);
    text-decoration: none;
}

.btn-primary {
    background: var(--gradient);
    color: var(--white);
    box-shadow: 0 4px 16px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(99, 102, 241, 0.4);
    color: var(--white);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text);
    border: 1px solid var(--border);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--border-light);
    color: var(--white);
    transform: translateY(-2px);
}

/* Hero Stats */
.hero-stats {
    display: flex;
    justify-content: center;
    gap: 60px;
}

.stat {
    text-align: center;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--white);
    display: inline;
    font-variant-numeric: tabular-nums;
}

.stat-suffix {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-light);
}

.stat-label {
    display: block;
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-top: 4px;
    font-weight: 500;
}

/* ===== Sections ===== */
.section {
    padding: 100px 0;
}

.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 60px;
}

.section-tag {
    display: inline-block;
    padding: 6px 16px;
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.15);
    border-radius: 100px;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--primary-light);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 20px;
}

.section-title {
    font-size: clamp(1.8rem, 4vw, 2.8rem);
    font-weight: 800;
    color: var(--white);
    letter-spacing: -0.02em;
    line-height: 1.2;
    margin-bottom: 16px;
}

.section-subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ===== Category Cards ===== */
.category-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.category-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 36px;
    transition: all var(--transition);
    color: var(--text);
    display: flex;
    flex-direction: column;
}

.category-card:hover {
    background: var(--bg-card-hover);
    border-color: var(--primary);
    transform: translateY(-4px);
    box-shadow: var(--shadow-glow);
    color: var(--text);
}

.category-icon {
    width: 64px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(99, 102, 241, 0.1);
    border-radius: var(--radius);
    margin-bottom: 20px;
    color: var(--primary-light);
}

.category-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 12px;
}

.category-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.7;
    flex-grow: 1;
    margin-bottom: 16px;
}

.category-link {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--primary-light);
    display: flex;
    align-items: center;
    gap: 6px;
}

.category-link span {
    transition: transform var(--transition);
}

.category-card:hover .category-link span {
    transform: translateX(4px);
}

/* ===== Articles ===== */
.articles-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
}

.article-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all var(--transition);
}

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

.article-featured {
    grid-column: 1 / -1;
    display: grid;
    grid-template-columns: 1.2fr 1fr;
}

.article-image-placeholder {
    width: 100%;
    height: 100%;
    min-height: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.article-featured .article-image-placeholder {
    min-height: 300px;
}

.article-content {
    padding: 28px;
    display: flex;
    flex-direction: column;
}

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

.article-category {
    padding: 4px 12px;
    background: rgba(99, 102, 241, 0.1);
    border-radius: 100px;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--primary-light);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.article-read {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.article-content h3 {
    font-size: 1.3rem;
    font-weight: 700;
    line-height: 1.35;
    margin-bottom: 12px;
}

.article-content h3 a {
    color: var(--white);
}

.article-content h3 a:hover {
    color: var(--primary-light);
}

.article-content p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.7;
    flex-grow: 1;
}

.article-footer {
    margin-top: 16px;
}

.article-date {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* ===== Knowledge Hub ===== */
.knowledge-hub {
    background: var(--bg-secondary);
}

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

.knowledge-content .section-title {
    text-align: left;
}

.knowledge-content > p {
    color: var(--text-secondary);
    margin-bottom: 40px;
    font-size: 1.05rem;
    line-height: 1.8;
}

.knowledge-features {
    display: flex;
    flex-direction: column;
    gap: 28px;
}

.knowledge-feature {
    display: flex;
    gap: 16px;
}

.feature-icon {
    width: 48px;
    height: 48px;
    min-width: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(99, 102, 241, 0.1);
    border-radius: var(--radius-sm);
    color: var(--primary-light);
}

.knowledge-feature h4 {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 4px;
}

.knowledge-feature p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Knowledge Visual */
.knowledge-visual {
    display: flex;
    justify-content: center;
}

.visual-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 40px;
    width: 100%;
    max-width: 400px;
}

.visual-chain {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
}

.chain-block {
    width: 100%;
    padding: 20px 24px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    text-align: center;
    transition: all var(--transition);
}

.chain-block.active {
    border-color: var(--primary);
    box-shadow: var(--shadow-glow);
    background: rgba(99, 102, 241, 0.05);
}

.block-label {
    display: block;
    font-weight: 700;
    font-size: 0.95rem;
    color: var(--white);
    margin-bottom: 4px;
}

.block-hash {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    color: var(--text-muted);
}

.chain-link {
    color: var(--primary-light);
    opacity: 0.5;
}

/* ===== Learning Path ===== */
.path-timeline {
    max-width: 700px;
    margin: 0 auto;
    position: relative;
}

.path-timeline::before {
    content: '';
    position: absolute;
    left: 24px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(to bottom, var(--primary), var(--secondary), var(--accent));
    border-radius: 2px;
}

.path-step {
    display: flex;
    gap: 28px;
    padding: 24px 0;
    position: relative;
}

.step-number {
    width: 50px;
    height: 50px;
    min-width: 50px;
    background: var(--gradient);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
    font-size: 1.1rem;
    color: var(--white);
    position: relative;
    z-index: 1;
    box-shadow: 0 0 20px rgba(99, 102, 241, 0.3);
}

.step-content h3 {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 8px;
}

.step-content p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.7;
    margin-bottom: 12px;
}

.step-link {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--primary-light);
}

.step-link:hover {
    color: var(--accent);
}

/* ===== Newsletter ===== */
.newsletter {
    padding: 60px 0;
}

.newsletter-card {
    background: var(--gradient);
    border-radius: var(--radius-lg);
    padding: 60px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.newsletter-card::before {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at top right, rgba(255,255,255,0.1), transparent 60%);
}

.newsletter-content {
    position: relative;
    z-index: 1;
}

.newsletter-content h2 {
    font-size: 2rem;
    font-weight: 800;
    color: var(--white);
    margin-bottom: 12px;
}

.newsletter-content p {
    color: rgba(255, 255, 255, 0.85);
    font-size: 1.05rem;
    margin-bottom: 28px;
}

.newsletter-form {
    display: flex;
    max-width: 500px;
    margin: 0 auto;
    gap: 12px;
    position: relative;
    z-index: 1;
}

.newsletter-form input {
    flex: 1;
    padding: 14px 20px;
    border-radius: var(--radius);
    border: 1px solid rgba(255, 255, 255, 0.2);
    background: rgba(255, 255, 255, 0.15);
    color: var(--white);
    font-size: 0.95rem;
    font-family: inherit;
    outline: none;
    transition: all var(--transition);
}

.newsletter-form input::placeholder {
    color: rgba(255, 255, 255, 0.6);
}

.newsletter-form input:focus {
    border-color: rgba(255, 255, 255, 0.5);
    background: rgba(255, 255, 255, 0.2);
}

.newsletter-form .btn {
    background: var(--white);
    color: var(--primary-dark);
    white-space: nowrap;
}

.newsletter-form .btn:hover {
    background: rgba(255, 255, 255, 0.9);
}

.newsletter-note {
    font-size: 0.8rem;
    color: rgba(255, 255, 255, 0.6);
    margin-top: 16px;
    position: relative;
    z-index: 1;
}

/* ===== FAQ ===== */
.faq {
    background: var(--bg-secondary);
}

.faq-grid {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.faq-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    transition: border-color var(--transition);
}

.faq-item.active {
    border-color: var(--primary);
}

.faq-question {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 24px;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    color: var(--white);
    font-family: inherit;
    text-align: left;
    gap: 16px;
}

.faq-icon {
    color: var(--text-muted);
    transition: transform var(--transition);
    min-width: 20px;
}

.faq-item.active .faq-icon {
    transform: rotate(180deg);
    color: var(--primary-light);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.4s ease;
}

.faq-item.active .faq-answer {
    max-height: 500px;
}

.faq-answer p {
    padding: 0 24px 20px;
    color: var(--text-secondary);
    line-height: 1.8;
    font-size: 0.95rem;
}

.faq-answer a {
    color: var(--primary-light);
    text-decoration: underline;
    text-underline-offset: 3px;
}

/* ===== Footer ===== */
.footer {
    padding: 80px 0 40px;
    border-top: 1px solid var(--border);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 48px;
    margin-bottom: 48px;
}

.footer-brand p {
    color: var(--text-secondary);
    margin-top: 16px;
    font-size: 0.9rem;
    line-height: 1.7;
    max-width: 300px;
}

.footer-links h4 {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--white);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 20px;
}

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

.footer-links a {
    color: var(--text-secondary);
    font-size: 0.9rem;
    transition: color var(--transition);
}

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

.footer-bottom {
    padding-top: 32px;
    border-top: 1px solid var(--border);
}

.footer-bottom p {
    font-size: 0.8rem;
    color: var(--text-muted);
    text-align: center;
    line-height: 1.6;
}

/* ===== Page Styles (for subpages) ===== */
.page-hero {
    padding: 140px 0 60px;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
}

.page-hero h1 {
    font-size: clamp(2rem, 5vw, 3.2rem);
    font-weight: 800;
    color: var(--white);
    letter-spacing: -0.02em;
    margin-bottom: 16px;
}

.page-hero p {
    font-size: 1.15rem;
    color: var(--text-secondary);
    max-width: 700px;
    line-height: 1.8;
}

.page-hero .breadcrumb {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 24px;
    font-size: 0.85rem;
}

.breadcrumb a {
    color: var(--text-muted);
}

.breadcrumb span {
    color: var(--text-muted);
}

.breadcrumb .current {
    color: var(--primary-light);
}

/* Page Content */
.page-content {
    padding: 80px 0;
}

.content-wrapper {
    max-width: 840px;
    margin: 0 auto;
}

.content-wrapper h2 {
    font-size: 1.8rem;
    font-weight: 800;
    color: var(--white);
    margin: 48px 0 20px;
    letter-spacing: -0.01em;
}

.content-wrapper h3 {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--white);
    margin: 36px 0 16px;
}

.content-wrapper h4 {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--white);
    margin: 28px 0 12px;
}

.content-wrapper p {
    color: var(--text-secondary);
    font-size: 1.05rem;
    line-height: 1.85;
    margin-bottom: 20px;
}

.content-wrapper ul,
.content-wrapper ol {
    margin: 16px 0 24px 24px;
    list-style: disc;
}

.content-wrapper ol {
    list-style: decimal;
}

.content-wrapper li {
    color: var(--text-secondary);
    font-size: 1.02rem;
    line-height: 1.8;
    margin-bottom: 8px;
    padding-left: 4px;
}

.content-wrapper strong {
    color: var(--white);
    font-weight: 600;
}

.content-wrapper blockquote {
    border-left: 3px solid var(--primary);
    padding: 16px 24px;
    margin: 24px 0;
    background: rgba(99, 102, 241, 0.05);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.content-wrapper blockquote p {
    color: var(--text);
    font-style: italic;
    margin-bottom: 0;
}

.content-wrapper code {
    font-family: 'JetBrains Mono', monospace;
    background: var(--surface);
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 0.9em;
    color: var(--primary-light);
}

.content-wrapper pre {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    overflow-x: auto;
    margin: 24px 0;
}

.content-wrapper pre code {
    background: none;
    padding: 0;
    font-size: 0.88rem;
    line-height: 1.7;
}

/* Info Box */
.info-box {
    background: rgba(99, 102, 241, 0.08);
    border: 1px solid rgba(99, 102, 241, 0.2);
    border-radius: var(--radius);
    padding: 24px 28px;
    margin: 28px 0;
}

.info-box.warning {
    background: rgba(245, 158, 11, 0.08);
    border-color: rgba(245, 158, 11, 0.2);
}

.info-box.danger {
    background: rgba(239, 68, 68, 0.08);
    border-color: rgba(239, 68, 68, 0.2);
}

.info-box.success {
    background: rgba(16, 185, 129, 0.08);
    border-color: rgba(16, 185, 129, 0.2);
}

.info-box h4 {
    margin-top: 0 !important;
    margin-bottom: 8px !important;
    font-size: 1rem;
}

.info-box p {
    margin-bottom: 0;
    font-size: 0.95rem;
}

/* Table of Contents */
.toc {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 28px 32px;
    margin: 0 0 48px;
}

.toc h3 {
    margin: 0 0 16px !important;
    font-size: 1.1rem;
}

.toc ol {
    margin: 0 0 0 20px !important;
}

.toc li {
    font-size: 0.95rem;
    margin-bottom: 6px;
}

.toc a {
    color: var(--text-secondary);
}

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

/* Comparison Table */
.comparison-table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    margin: 24px 0 32px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
}

.comparison-table th,
.comparison-table td {
    padding: 14px 20px;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

.comparison-table th {
    background: var(--surface);
    font-weight: 700;
    color: var(--white);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.comparison-table td {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.comparison-table tr:last-child td {
    border-bottom: none;
}

.comparison-table tr:hover td {
    background: rgba(99, 102, 241, 0.03);
}

/* Glossary */
.glossary-section {
    margin-bottom: 48px;
}

.glossary-letter {
    font-size: 2rem;
    font-weight: 800;
    color: var(--primary-light);
    margin-bottom: 20px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--border);
}

.glossary-term {
    margin-bottom: 24px;
}

.glossary-term dt {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 6px;
}

.glossary-term dd {
    color: var(--text-secondary);
    font-size: 0.98rem;
    line-height: 1.7;
    padding-left: 16px;
    border-left: 2px solid var(--border);
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
    .category-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .knowledge-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .knowledge-visual {
        order: -1;
    }

    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 36px;
    }
}

@media (max-width: 768px) {
    .nav {
        display: none;
        position: fixed;
        top: var(--header-height);
        left: 0;
        right: 0;
        background: rgba(10, 10, 15, 0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 24px;
        border-bottom: 1px solid var(--border);
    }

    .nav.active {
        display: flex;
    }

    .nav-toggle {
        display: flex;
    }

    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

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

    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(5px, -5px);
    }

    .hero-title {
        font-size: 2.2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .hero-cta {
        flex-direction: column;
        align-items: center;
    }

    .hero-stats {
        flex-direction: column;
        gap: 24px;
    }

    .category-grid {
        grid-template-columns: 1fr;
    }

    .articles-grid {
        grid-template-columns: 1fr;
    }

    .article-featured {
        grid-column: auto;
        grid-template-columns: 1fr;
    }

    .section {
        padding: 60px 0;
    }

    .newsletter-card {
        padding: 40px 24px;
    }

    .newsletter-form {
        flex-direction: column;
    }

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

    .path-timeline::before {
        display: none;
    }

    .step-number {
        width: 40px;
        height: 40px;
        min-width: 40px;
        font-size: 0.95rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

    .hero-title {
        font-size: 1.8rem;
    }

    .section-title {
        font-size: 1.5rem;
    }

    .category-card {
        padding: 24px;
    }

    .btn {
        padding: 12px 24px;
        font-size: 0.9rem;
    }
}

/* ===== Animations ===== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-in {
    animation: fadeInUp 0.6s ease forwards;
    opacity: 0;
}

.animate-in:nth-child(2) { animation-delay: 0.1s; }
.animate-in:nth-child(3) { animation-delay: 0.2s; }
.animate-in:nth-child(4) { animation-delay: 0.3s; }
.animate-in:nth-child(5) { animation-delay: 0.4s; }
.animate-in:nth-child(6) { animation-delay: 0.5s; }

/* Smooth scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg);
}

::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--border-light);
}

/* Selection */
::selection {
    background: rgba(99, 102, 241, 0.3);
    color: var(--white);
}

/* ===== SKIP TO CONTENT ===== */
.skip-link { position: absolute; top: -100%; left: 16px; background: var(--primary); color: #fff; padding: 12px 24px; border-radius: 0 0 8px 8px; font-weight: 700; font-size: 0.9rem; z-index: 9999; transition: top 0.2s; }
.skip-link:focus { top: 0; }

/* ===== READING PROGRESS BAR ===== */
.progress-bar { position: fixed; top: 0; left: 0; height: 3px; background: var(--gradient); z-index: 1001; width: 0%; transition: width 0.1s linear; pointer-events: none; }

/* ===== BACK TO TOP ===== */
.back-to-top { position: fixed; bottom: 32px; right: 32px; width: 48px; height: 48px; border-radius: 50%; background: var(--primary); color: #fff; border: none; cursor: pointer; display: flex; align-items: center; justify-content: center; z-index: 900; opacity: 0; transform: translateY(16px); transition: all 0.3s; box-shadow: 0 4px 16px rgba(99,102,241,0.35); }
.back-to-top.visible { opacity: 1; transform: translateY(0); }
.back-to-top:hover { background: var(--primary-light); transform: translateY(-3px); box-shadow: 0 6px 24px rgba(99,102,241,0.45); }
.back-to-top:focus-visible { outline: 2px solid var(--secondary); outline-offset: 3px; }
.back-to-top svg { width: 20px; height: 20px; fill: none; stroke: currentColor; stroke-width: 2.5; stroke-linecap: round; stroke-linejoin: round; }

/* ===== TABLE OF CONTENTS ===== */
.toc { background: var(--bg-card, var(--surface, rgba(255,255,255,0.03))); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px 28px; margin: 32px 0; }
.toc h3 { font-size: 1rem; text-transform: uppercase; letter-spacing: 1px; color: var(--text-secondary, var(--text-muted)); margin-bottom: 12px; }
.toc ol { padding-left: 20px; }
.toc li { margin-bottom: 6px; }
.toc a { color: var(--primary-light, var(--primary)); font-size: 0.95rem; }
.toc a:hover { color: var(--secondary, var(--accent)); }

/* ===== RELATED GUIDES ===== */
.related-guides { padding: 64px 0; border-top: 1px solid var(--border); }
.related-guides h2 { text-align: center; margin-bottom: 40px; }
.related-guides .guide-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 24px; }
.related-guides .guide-card { background: var(--bg-card, var(--surface, rgba(255,255,255,0.03))); border: 1px solid var(--border); border-radius: var(--radius); padding: 28px; transition: all 0.3s; }
.related-guides .guide-card:hover { border-color: var(--primary); transform: translateY(-4px); box-shadow: var(--shadow-lg, 0 12px 40px rgba(0,0,0,0.3)); }
.related-guides .guide-card h3 { color: var(--primary-light, var(--primary)); margin-bottom: 8px; font-size: 1.15rem; }
.related-guides .guide-card p { color: var(--text-secondary, var(--text-muted)); font-size: 0.95rem; line-height: 1.6; }
.guide-card-link { text-decoration: none; color: inherit; }

/* ===== TABLE WRAPPER ===== */
.table-wrapper { overflow-x: auto; margin: 24px 0; border-radius: var(--radius); border: 1px solid var(--border); }
.table-wrapper table { min-width: 600px; }

/* ===== FOCUS VISIBLE ===== */
*:focus-visible { outline: 2px solid var(--primary-light, var(--primary)); outline-offset: 2px; }
input:focus-visible, textarea:focus-visible, button:focus-visible { outline-offset: 0; }

/* ===== PERFORMANCE ===== */
.faq, .newsletter, .footer { content-visibility: auto; contain-intrinsic-size: auto 500px; }

/* ===== REDUCED MOTION ===== */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; scroll-behavior: auto !important; }
    .reveal, .animate-in { opacity: 1; transform: none; animation: none; }
    .back-to-top { transition: none; }
}

/* ===== HIGH CONTRAST ===== */
@media (prefers-contrast: high) {
    :root { --border: rgba(255,255,255,0.2); }
    .card, .faq-item { border: 1px solid rgba(255,255,255,0.3); }
}

/* ===== PRINT STYLES ===== */
@media print {
    .header, .nav-toggle, .back-to-top, .progress-bar, .newsletter, .footer, .related-guides { display: none !important; }
    body { background: #fff; color: #111; font-size: 12pt; line-height: 1.5; }
    .hero, .page-hero { padding: 20px 0; background: none !important; }
    a[href]::after { content: " (" attr(href) ")"; font-size: 0.85em; color: #666; }
    .card, section { break-inside: avoid; }
}

/* ===== COOKIE CONSENT ===== */
.cookie-banner { position: fixed; bottom: 0; left: 0; right: 0; background: rgba(20,20,30,0.97); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); border-top: 1px solid var(--border); padding: 16px 24px; z-index: 9998; display: flex; align-items: center; justify-content: center; gap: 16px; flex-wrap: wrap; font-size: 0.9rem; transform: translateY(100%); transition: transform 0.4s ease; }
.cookie-banner.visible { transform: translateY(0); }
.cookie-banner p { color: var(--text-secondary, #a1a1aa); max-width: 600px; line-height: 1.5; margin: 0; }
.cookie-banner a { color: var(--primary-light, var(--primary)); text-decoration: underline; }
.cookie-btn { background: var(--primary); color: #fff; border: none; padding: 10px 24px; border-radius: 6px; font-weight: 600; cursor: pointer; font-size: 0.9rem; white-space: nowrap; transition: background 0.2s; }
.cookie-btn:hover { opacity: 0.9; }
.cookie-btn.secondary { background: transparent; border: 1px solid var(--border); color: var(--text-secondary, #a1a1aa); }
.cookie-btn.secondary:hover { border-color: var(--primary); color: var(--primary-light, var(--primary)); }

/* ===== BREADCRUMBS ===== */
.breadcrumbs { padding: 12px 0; font-size: 0.85rem; color: var(--text-muted, var(--text-secondary, #71717a)); }
.breadcrumbs a { color: var(--primary-light, var(--primary)); }
.breadcrumbs a:hover { text-decoration: underline; }
.breadcrumbs .separator { margin: 0 8px; opacity: 0.5; }

/* ===== ARTICLE META (reading time, last updated, share) ===== */
.article-meta { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; padding: 16px 0; margin-bottom: 24px; border-bottom: 1px solid var(--border); font-size: 0.85rem; color: var(--text-muted, var(--text-secondary, #71717a)); }
.article-meta svg { width: 16px; height: 16px; vertical-align: -2px; margin-right: 4px; stroke: currentColor; fill: none; }
.reading-time, .last-updated { display: flex; align-items: center; gap: 4px; }
.share-btn { display: inline-flex; align-items: center; gap: 6px; background: rgba(255,255,255,0.06); border: 1px solid var(--border); color: var(--text-secondary, #a1a1aa); padding: 6px 14px; border-radius: 6px; font-size: 0.85rem; cursor: pointer; transition: all 0.2s; font-family: inherit; }
.share-btn:hover { border-color: var(--primary); color: var(--primary-light, var(--primary)); background: rgba(99,102,241, 0.08); }
.share-btn.copied { border-color: var(--success, #10b981); color: var(--success, #10b981); }
.share-btn svg { width: 14px; height: 14px; }

/* ===== PAGE LOAD ANIMATION ===== */
@keyframes fadeInPage { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }
.page-hero, .hero { animation: fadeInPage 0.5s ease both; }
.content-wrapper { animation: fadeInPage 0.5s ease 0.1s both; }

/* ===== GLOSSARY SEARCH ===== */
.glossary-section { background: rgba(99,102,241,0.03); }
.glossary-search-card { max-width: 700px; margin: 0 auto; }
.glossary-input { width: 100%; padding: 14px 20px 14px 48px; background: rgba(99,102,241,0.06); border: 1px solid var(--border); border-radius: 12px; color: var(--text, #fff); font-size: 1rem; font-family: inherit; background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='20' height='20' viewBox='0 0 24 24' fill='none' stroke='%236366f1' stroke-width='2'%3E%3Ccircle cx='11' cy='11' r='8'/%3E%3Cline x1='21' y1='21' x2='16.65' y2='16.65'/%3E%3C/svg%3E"); background-repeat: no-repeat; background-position: 16px center; }
.glossary-input:focus { outline: none; border-color: var(--primary); }
.glossary-input::placeholder { color: var(--muted, #666); }
.glossary-count { text-align: center; font-size: 0.8rem; color: var(--muted, #888); margin-top: 8px; }
.glossary-list { margin-top: 20px; display: grid; gap: 8px; max-height: 500px; overflow-y: auto; }
.glossary-term { padding: 16px; background: rgba(99,102,241,0.04); border: 1px solid var(--border); border-radius: 10px; transition: all 0.2s; }
.glossary-term:hover { border-color: var(--primary); background: rgba(99,102,241,0.08); }
.glossary-term strong { color: var(--primary); font-size: 1rem; display: block; margin-bottom: 4px; }
.glossary-term span { font-size: 0.85rem; color: var(--muted, #bbb); line-height: 1.5; }
.glossary-term.hidden { display: none; }

/* ===== NEWSLETTER ===== */
.newsletter-section { text-align: center; }
.newsletter-form { display: flex; gap: 10px; max-width: 440px; margin: 0 auto; flex-wrap: wrap; justify-content: center; }
.newsletter-input { flex: 1; min-width: 200px; padding: 14px 20px; border-radius: 8px; border: 1px solid var(--border); background: rgba(99,102,241,0.06); color: var(--text, #fff); font-size: 1rem; font-family: inherit; }
.newsletter-input:focus { outline: none; border-color: var(--primary); }
.newsletter-btn { padding: 14px 28px; background: var(--primary); color: #fff; border: none; border-radius: 8px; font-weight: 600; font-size: 1rem; cursor: pointer; font-family: inherit; transition: opacity 0.2s; }
.newsletter-btn:hover { opacity: 0.9; }
.newsletter-btn:disabled { opacity: 0.7; cursor: default; }