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

:root {
    --primary-color: #60a5fa;
    --primary-hover: #3b82f6;
    --text-dark: #f9fafb;
    --text-medium: #d1d5db;
    --text-light: #9ca3af;
    --bg-light: #1f2937;
    --bg-white: #111827;
    --border: #374151;
    --accent: #60a5fa;
    --success: #10b981;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background: var(--bg-white);
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
header {
    background: var(--bg-white);
    border-bottom: 1px solid var(--border);
    padding: 20px 0;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
    background: rgba(17, 24, 39, 0.95);
}

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

.logo {
    font-size: 26px;
    font-weight: 300;
    color: var(--primary-color);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 6px;
}

.logo-emoji {
    display: flex;
    align-items: center;
    transform: translateY(2px);
}

.header-link {
    color: var(--text-medium);
    text-decoration: none;
    font-size: 14px;
    padding: 8px 16px;
    border-radius: 6px;
    transition: all 0.2s;
    border: 1px solid var(--border);
}

.header-link:hover {
    background: var(--bg-light);
    border-color: var(--primary-color);
    color: var(--primary-color);
}

/* Hero Section */
.hero {
    padding: 60px 0 40px;
    text-align: center;
}

h1 {
    font-size: 42px;
    font-weight: 800;
    color: var(--text-dark);
    margin-bottom: 16px;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 20px;
    color: var(--text-medium);
    margin-bottom: 24px;
}

.hero-cta {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    margin-top: 32px;
    flex-wrap: wrap;
}

.social-proof {
    color: var(--text-light);
    font-size: 14px;
    display: flex;
    align-items: center;
    gap: 6px;
}

.social-proof svg {
    color: var(--success);
}

/* Stats Section */
.stats {
    background: var(--bg-light);
    border-radius: 12px;
    padding: 40px 32px;
    margin: 40px 0;
}

.stats h2 {
    font-size: 28px;
    margin-bottom: 32px;
    text-align: center;
    color: var(--text-dark);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 24px;
    margin-bottom: 24px;
}

.stat-box {
    text-align: center;
    padding: 24px;
    background: var(--bg-white);
    border-radius: 8px;
    border: 1px solid var(--border);
}

.stat-number {
    font-size: 36px;
    font-weight: 800;
    color: var(--primary-color);
    margin-bottom: 8px;
}

.stat-label {
    font-size: 14px;
    color: var(--text-medium);
    line-height: 1.4;
}

/* Definition Section */
.definition {
    background: var(--bg-light);
    border-radius: 12px;
    padding: 32px;
    margin: 40px 0;
}

.definition h2 {
    font-size: 28px;
    margin-bottom: 16px;
    color: var(--text-dark);
}

.definition p {
    font-size: 17px;
    line-height: 1.8;
    color: var(--text-medium);
    margin-bottom: 16px;
}

.definition-example {
    background: var(--bg-white);
    padding: 20px;
    border-radius: 8px;
    border-left: 4px solid var(--primary-color);
    margin-top: 20px;
}

.definition-example strong {
    color: var(--primary-color);
    font-size: 18px;
}

/* Use Cases */
.use-cases {
    margin: 60px 0;
}

.use-cases h2 {
    font-size: 32px;
    text-align: center;
    margin-bottom: 40px;
    color: var(--text-dark);
}

.use-case-card {
    background: var(--bg-light);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 32px;
    margin-bottom: 24px;
    transition: box-shadow 0.3s, transform 0.3s;
}

.use-case-card:hover {
    box-shadow: 0 10px 30px rgba(96, 165, 250, 0.1);
    transform: translateY(-2px);
    border-color: var(--primary-color);
}

.use-case-card h3 {
    font-size: 22px;
    margin-bottom: 12px;
    color: var(--text-dark);
    display: flex;
    align-items: center;
    gap: 12px;
}

.use-case-card h3 svg {
    flex-shrink: 0;
    color: var(--primary-color);
}

.use-case-card p {
    color: var(--text-medium);
    margin-bottom: 20px;
    font-size: 16px;
    line-height: 1.7;
}

/* Examples Section */
.examples {
    margin: 60px 0;
    background: var(--bg-light);
    padding: 40px 32px;
    border-radius: 12px;
}

.examples h2 {
    font-size: 28px;
    margin-bottom: 24px;
    color: var(--text-dark);
}

.examples-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 16px;
    margin-bottom: 24px;
}

.example-item {
    background: var(--bg-white);
    padding: 16px;
    border-radius: 8px;
    text-align: center;
    border: 1px solid var(--border);
    transition: border-color 0.2s;
}

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

.example-item strong {
    color: var(--primary-color);
    font-size: 16px;
    display: block;
    margin-bottom: 4px;
}

.example-arrow {
    color: var(--text-light);
    margin: 4px 0;
}

/* FAQ Section */
.faq {
    margin: 60px 0;
}

.faq h2 {
    font-size: 32px;
    margin-bottom: 32px;
    text-align: center;
    color: var(--text-dark);
}

.faq-item {
    background: var(--bg-light);
    border: 1px solid var(--border);
    border-radius: 12px;
    margin-bottom: 16px;
    overflow: hidden;
}

.faq-question {
    padding: 24px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background 0.2s;
}

.faq-question:hover {
    background: rgba(96, 165, 250, 0.05);
}

.faq-question h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-dark);
    margin: 0;
    flex: 1;
}

.faq-toggle {
    color: var(--primary-color);
    font-size: 24px;
    font-weight: 300;
    transition: transform 0.3s;
    min-width: 24px;
    text-align: center;
}

.faq-item.active .faq-toggle {
    transform: rotate(45deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
}

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

.faq-answer-content {
    padding: 0 24px 24px 24px;
    color: var(--text-medium);
    line-height: 1.8;
}

.faq-answer-content p {
    margin-bottom: 12px;
}

.faq-answer-content a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
}

.faq-answer-content a:hover {
    text-decoration: underline;
}

/* History Section */
.history {
    margin: 60px 0;
}

.history h2 {
    font-size: 28px;
    margin-bottom: 20px;
    color: var(--text-dark);
}

.history p {
    font-size: 17px;
    line-height: 1.8;
    color: var(--text-medium);
    margin-bottom: 16px;
}

.history-highlight {
    background: var(--bg-light);
    padding: 20px;
    border-radius: 8px;
    margin-top: 20px;
    border-left: 4px solid var(--accent);
}

.history-highlight p {
    margin: 0;
    font-style: italic;
}

/* Uses Section */
.uses {
    margin: 60px 0;
    background: var(--bg-light);
    border-radius: 12px;
    padding: 40px;
}

.uses h2 {
    font-size: 28px;
    margin-bottom: 24px;
    color: var(--text-dark);
}

.uses ul {
    list-style: none;
    padding: 0;
}

.uses li {
    padding: 16px 0;
    border-bottom: 1px solid var(--border);
    font-size: 17px;
    color: var(--text-medium);
    padding-left: 32px;
    position: relative;
}

.uses li:last-child {
    border-bottom: none;
}

.uses li:before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
    font-size: 20px;
}

/* Related Pages */
.related-pages {
    margin: 60px 0;
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 32px;
}

.related-pages h3 {
    font-size: 22px;
    margin-bottom: 20px;
    color: var(--text-dark);
}

.related-links {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 12px;
}

.related-links a {
    color: var(--text-medium);
    text-decoration: none;
    padding: 12px;
    border-radius: 6px;
    border: 1px solid var(--border);
    display: flex;
    align-items: center;
    gap: 8px;
    transition: all 0.2s;
}

.related-links a:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
    background: var(--bg-light);
}

.related-links a:before {
    content: "→";
    color: var(--primary-color);
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 14px 28px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    font-size: 16px;
    transition: all 0.2s;
    border: none;
    cursor: pointer;
}

.btn-primary {
    background: #1d4ed8;
    color: white;
}

.btn-primary:hover {
    background: #1e40af;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(96, 165, 250, 0.3);
}

.btn-secondary {
    background: var(--bg-white);
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

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

/* CTA Section */
.cta {
    text-align: center;
    margin: 80px 0 60px;
    padding: 60px 40px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent) 100%);
    border-radius: 16px;
    color: white;
}

.cta h2 {
    font-size: 32px;
    margin-bottom: 16px;
    color: white;
}

.cta p {
    font-size: 18px;
    margin-bottom: 32px;
    opacity: 0.95;
}

.cta .btn {
    background: white;
    color: #1d4ed8;
    font-size: 18px;
    padding: 16px 36px;
}

.cta .btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(0,0,0,0.2);
}

/* Footer */
footer {
    background: var(--bg-light);
    padding: 40px 0;
    margin-top: 80px;
    border-top: 1px solid var(--border);
}

.footer-content {
    text-align: center;
}

.footer-links {
    margin-bottom: 20px;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 8px 24px;
}

.footer-links a {
    color: var(--text-medium);
    text-decoration: none;
    font-size: 14px;
}

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

.footer-text {
    color: var(--text-light);
    font-size: 14px;
}

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

.footer-text a:hover {
    text-decoration: underline;
}

/* Word Exploration Section */
.word-exploration {
    margin: 60px 0;
    background: var(--bg-light);
    padding: 40px 32px;
    border-radius: 12px;
}

.word-exploration h3 {
    font-size: 24px;
    margin-bottom: 16px;
    color: var(--text-dark);
}

.word-exploration > p {
    color: var(--text-medium);
    margin-bottom: 24px;
    line-height: 1.7;
}

.word-exploration-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 16px;
}

.word-exploration-link {
    color: var(--primary-color);
    text-decoration: none;
    padding: 32px 24px;
    background: var(--bg-white);
    border-radius: 8px;
    border: 1px solid var(--border);
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    min-height: 100px;
    font-size: 16px;
    line-height: 1.4;
}

.word-exploration-link:hover {
    transform: translateY(-1px);
    border-color: var(--primary-color);
    box-shadow: 0 2px 8px rgba(96, 165, 250, 0.15);
}

/* Utility Classes */
.text-center {
    text-align: center;
}

.text-medium {
    color: var(--text-medium);
}

.mb-24 {
    margin-bottom: 24px;
}

.mt-20 {
    margin-top: 20px;
}

.link-primary {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
}

.link-primary:hover {
    text-decoration: underline;
}

/* Responsive */
@media (max-width: 768px) {
    h1 {
        font-size: 32px;
    }
    
    .hero-subtitle {
        font-size: 18px;
    }
    
    .hero-cta {
        flex-direction: column;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .definition,
    .use-case-card,
    .uses,
    .related-pages {
        padding: 24px;
    }
    
    .examples {
        padding: 24px;
    }
    
    .examples-grid {
        grid-template-columns: 1fr;
    }
    
    .cta {
        padding: 40px 24px;
    }
    
    .cta h2 {
        font-size: 26px;
    }
    
    .related-links {
        grid-template-columns: 1fr;
    }
    
    .word-exploration {
        padding: 24px;
    }
    
    .word-exploration-grid {
        grid-template-columns: 1fr;
    }
}