:root {
    --primary: #3B82F6;
    --secondary: #10B981;
    --accent: #F59E0B;
    --danger: #EF4444;
    --background: #F9FAFB;
    --surface: #FFFFFF;
    --text-primary: #1F2937;
    --text-secondary: #6B7280;
    --border: #E5E7EB;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', sans-serif;
    background-color: var(--background);
    color: var(--text-primary);
}

.font-mono {
    font-family: 'JetBrains Mono', 'Fira Code', monospace;
}

.navbar {
    backdrop-filter: blur(10px);
    background: rgba(255, 255, 255, 0.95);
}

.section-fade {
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.6s ease;
}

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

.timeline-dot {
    transition: all 0.3s ease;
}

.timeline-item:hover .timeline-dot {
    transform: scale(1.1);
}

.bar-fill {
    transition: width 1.5s ease;
}

.scroll-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 3rem;
    height: 3rem;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 50%;
    font-size: 1.25rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 1000;
}

.scroll-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.scroll-to-top:hover {
    background: #2563EB;
    transform: translateY(-2px);
}

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

.faq-item.expanded .faq-answer {
    max-height: 1000px;
}

.source-card {
    transition: all 0.3s ease;
}

.source-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}