:root{--bg-primary: #FFFFFF;--bg-soft: #F8FAFC;--surface: #FFFFFF;--text-primary: #1A1A1A;--text-secondary: #4B5563;--text-muted: #6B7280;--border: #E5E7EB;--brand-blue: #4F46E5;--brand-blue-hover: #4338CA;--brand-blue-soft: #EEF0FB;--green-up: #10B981;--red-down: #EF4444;--amber: #F59E0B;--font-display: 'Source Serif 4',Georgia,'Times New Roman',serif;--font-body: 'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif;--font-mono: 'JetBrains Mono','SFMono-Regular',Consolas,monospace;--fs-caption: 12px;--fs-body: 17px;--fs-h3: 21px;--fs-h2: 26px;--fs-h1: 33px;--fs-display: 41px;--lh-tight: 1.1;--lh-heading: 1.25;--lh-snug: 1.3;--lh-body: 1.5;--lh-relaxed: 1.6;--space-1: 4px;--space-2: 8px;--space-3: 16px;--space-4: 24px;--space-5: 32px;--space-6: 40px;--space-7: 48px;--space-8: 64px;--space-9: 96px;--container-max: 1200px;--article-max: 680px;--mobile-margin: 16px;--desktop-margin: 32px;--radius-sm: 8px;--radius: 12px;--radius-pill: 999px;--touch-min: 48px;--header-height: 64px;--bottom-nav-height: 64px;--transition-fast: 150ms ease;--transition: 250ms ease}[data-theme="dark"]{--bg-primary: #0D1117;--bg-soft: #161B22;--surface: #151A23;--text-primary: #E6EDF3;--text-secondary: #9CA3AF;--text-muted: #8B949E;--border: #2A2F3A;--brand-blue: #818CF8;--brand-blue-hover: #A5B4FC;--brand-blue-soft: #1E1B4B;--green-up: #3FD99B;--red-down: #FF6B6B;--amber: #FBBF24}