:root{--color-primary: #0f172a;--color-secondary: #0ea5e9;--color-accent: #f59e0b;--color-accent-glow: #fbbf24;--color-surface: #1e293b;--color-surface-light: #334155;--color-text: #f8fafc;--color-text-muted: #94a3b8;--color-border: #475569;--gradient-cosmic: linear-gradient(135deg, #0f172a 0%, #1e1b4b 50%, #0f172a 100%);--gradient-card: linear-gradient(145deg, #1e293b 0%, #0f172a 100%);--gradient-accent: linear-gradient(135deg, #f59e0b 0%, #ea580c 100%);--gradient-quantum: linear-gradient(135deg, #0ea5e9 0%, #8b5cf6 50%, #ec4899 100%);--font-display: "Noto Serif SC", "Songti SC", serif;--font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;--font-mono: "JetBrains Mono", "Fira Code", monospace;--space-xs: .25rem;--space-sm: .5rem;--space-md: 1rem;--space-lg: 2rem;--space-xl: 4rem;--space-2xl: 6rem;--radius-sm: 4px;--radius-md: 8px;--radius-lg: 16px;--radius-full: 9999px;--shadow-sm: 0 2px 4px rgba(0, 0, 0, .3);--shadow-md: 0 4px 12px rgba(0, 0, 0, .4);--shadow-lg: 0 8px 32px rgba(0, 0, 0, .5);--shadow-glow: 0 0 20px rgba(14, 165, 233, .3);--transition-fast: .15s ease;--transition-base: .25s ease;--transition-slow: .4s ease;--max-width: 1200px;--header-height: 80px}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}html{scroll-behavior:smooth;font-size:16px}body{font-family:var(--font-body);background:var(--gradient-cosmic);color:var(--color-text);line-height:1.6;min-height:100vh;overflow-x:hidden}h1,h2,h3,h4,h5,h6{font-family:var(--font-display);font-weight:700;line-height:1.2;letter-spacing:.02em}h1{font-size:clamp(2.5rem,6vw,4rem)}h2{font-size:clamp(1.75rem,4vw,2.5rem)}h3{font-size:clamp(1.25rem,3vw,1.75rem)}p{color:var(--color-text-muted)}a{color:var(--color-secondary);text-decoration:none;transition:color var(--transition-fast)}a:hover{color:var(--color-accent)}.container{width:100%;max-width:var(--max-width);margin:0 auto;padding:0 var(--space-md)}.hero{position:relative;min-height:100vh;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;padding:var(--space-xl) var(--space-md);overflow:hidden}.hero:before{content:"";position:absolute;inset:0;background-image:radial-gradient(2px 2px at 20px 30px,#fff,transparent),radial-gradient(2px 2px at 40px 70px,rgba(255,255,255,.8),transparent),radial-gradient(1px 1px at 90px 40px,#fff,transparent),radial-gradient(2px 2px at 130px 80px,rgba(255,255,255,.6),transparent),radial-gradient(1px 1px at 160px 120px,#fff,transparent),radial-gradient(2px 2px at 200px 50px,rgba(255,255,255,.7),transparent),radial-gradient(1px 1px at 250px 160px,#fff,transparent),radial-gradient(2px 2px at 300px 90px,rgba(255,255,255,.5),transparent),radial-gradient(1px 1px at 350px 200px,#fff,transparent),radial-gradient(2px 2px at 400px 150px,rgba(255,255,255,.8),transparent);background-size:450px 250px;animation:twinkle 8s ease-in-out infinite;opacity:.6}@keyframes twinkle{0%,to{opacity:.6}50%{opacity:.8}}.hero:after{content:"";position:absolute;top:20%;left:50%;transform:translate(-50%);width:600px;height:600px;background:radial-gradient(circle,rgba(14,165,233,.15) 0%,transparent 70%);pointer-events:none}.hero-content{position:relative;z-index:1}.hero-title{font-size:clamp(3rem,8vw,6rem);background:linear-gradient(135deg,#fff 0%,var(--color-secondary) 50%,var(--color-accent) 100%);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;margin-bottom:var(--space-md);text-shadow:0 0 40px rgba(14,165,233,.3);animation:titleGlow 3s ease-in-out infinite alternate}@keyframes titleGlow{0%{filter:drop-shadow(0 0 20px rgba(14,165,233,.3))}to{filter:drop-shadow(0 0 40px rgba(245,158,11,.4))}}.hero-subtitle{font-family:var(--font-display);font-size:clamp(1rem,2.5vw,1.5rem);color:var(--color-text-muted);margin-bottom:var(--space-xl);font-weight:400}.scroll-indicator{position:absolute;bottom:var(--space-xl);left:50%;transform:translate(-50%);display:flex;flex-direction:column;align-items:center;gap:var(--space-sm);color:var(--color-text-muted);font-size:.875rem;animation:bounce 2s ease-in-out infinite}@keyframes bounce{0%,to{transform:translate(-50%) translateY(0)}50%{transform:translate(-50%) translateY(10px)}}.scroll-indicator svg{width:24px;height:24px}.edifice-section{padding:var(--space-2xl) 0}.edifice-visual{position:relative;max-width:400px;margin:0 auto var(--space-2xl)}.building{display:flex;flex-direction:column;align-items:center;gap:4px}.floor{display:flex;align-items:flex-end;justify-content:center;gap:4px;transition:transform var(--transition-base)}.floor:hover{transform:scale(1.02)}.floor-block{background:var(--gradient-card);border:1px solid var(--color-border);border-radius:var(--radius-sm);display:flex;align-items:center;justify-content:center;font-family:var(--font-display);font-size:.75rem;color:var(--color-text-muted);transition:all var(--transition-base);cursor:pointer}.floor-block:hover{border-color:var(--color-secondary);box-shadow:var(--shadow-glow);color:var(--color-text)}.floor.foundation .floor-block{width:180px;height:40px}.floor.level-1 .floor-block{width:160px;height:50px}.floor.level-2 .floor-block{width:140px;height:50px}.floor.level-3 .floor-block{width:120px;height:50px}.floor.level-4 .floor-block{width:100px;height:50px}.floor.spire .floor-block{width:60px;height:60px;background:var(--gradient-quantum);border:none;border-radius:50% 50% 10% 10%;font-size:1.5rem}.floor:before{content:"";position:absolute;bottom:100%;left:50%;transform:translate(-50%);width:2px;height:20px;background:linear-gradient(to top,var(--color-secondary),transparent)}.floor:first-child:before{display:none}.topics-section{padding:var(--space-2xl) 0}.section-title{text-align:center;margin-bottom:var(--space-xl);color:var(--color-text)}.section-title span{color:var(--color-accent)}.topics-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(320px,1fr));gap:var(--space-lg)}.topic-card{position:relative;background:var(--gradient-card);border:1px solid var(--color-border);border-radius:var(--radius-lg);padding:var(--space-lg);overflow:hidden;transition:all var(--transition-base);cursor:pointer}.topic-card:before{content:"";position:absolute;inset:0;background:linear-gradient(135deg,transparent 0%,rgba(14,165,233,.05) 100%);opacity:0;transition:opacity var(--transition-base)}.topic-card:hover{transform:translateY(-8px);border-color:var(--color-secondary);box-shadow:var(--shadow-lg),var(--shadow-glow)}.topic-card:hover:before{opacity:1}.card-level{position:absolute;top:var(--space-md);right:var(--space-md);background:var(--gradient-accent);color:var(--color-primary);font-family:var(--font-mono);font-size:.75rem;font-weight:700;padding:var(--space-xs) var(--space-sm);border-radius:var(--radius-full)}.card-icon{font-size:3rem;margin-bottom:var(--space-md);display:block}.card-title{font-family:var(--font-display);font-size:1.5rem;color:var(--color-text);margin-bottom:var(--space-xs)}.card-subtitle{font-size:.875rem;color:var(--color-secondary);margin-bottom:var(--space-md);text-transform:uppercase;letter-spacing:.1em}.card-description{font-size:.95rem;line-height:1.7;margin-bottom:var(--space-md)}.card-meta{display:flex;flex-wrap:wrap;gap:var(--space-sm);padding-top:var(--space-md);border-top:1px solid var(--color-border)}.card-tag{font-size:.75rem;color:var(--color-text-muted);background:var(--color-surface);padding:var(--space-xs) var(--space-sm);border-radius:var(--radius-full)}.topic-card.foundation{border-left:4px solid #64748b}.topic-card.electromagnetism{border-left:4px solid #0ea5e9}.topic-card.relativity{border-left:4px solid #8b5cf6}.topic-card.quantum{border-left:4px solid #ec4899}.topic-card.particles{border-left:4px solid #f59e0b}.topic-card.cosmology{border-left:4px solid #10b981}.footer{padding:var(--space-xl) 0;text-align:center;border-top:1px solid var(--color-border);margin-top:var(--space-2xl)}.footer-content{display:flex;flex-direction:column;align-items:center;gap:var(--space-md)}.footer-logo{font-family:var(--font-display);font-size:1.25rem;color:var(--color-text)}.footer-text{font-size:.875rem;color:var(--color-text-muted)}.footer-links{display:flex;gap:var(--space-lg)}@media(max-width:768px){:root{--space-xl: 3rem;--space-2xl: 4rem}.topics-grid{grid-template-columns:1fr}.floor.foundation .floor-block{width:140px}.floor.level-1 .floor-block{width:120px}.floor.level-2 .floor-block{width:100px}.floor.level-3 .floor-block{width:80px}.floor.level-4 .floor-block{width:60px}.floor.spire .floor-block{width:40px;height:40px;font-size:1rem}}@media(max-width:480px){.hero-title{font-size:2.5rem}.topic-card{padding:var(--space-md)}}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}@keyframes fadeInUp{0%{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}.hero-content{animation:fadeInUp 1s ease-out}.topic-card{animation:fadeInUp .6s ease-out backwards}.topic-card:nth-child(1){animation-delay:.1s}.topic-card:nth-child(2){animation-delay:.2s}.topic-card:nth-child(3){animation-delay:.3s}.topic-card:nth-child(4){animation-delay:.4s}.topic-card:nth-child(5){animation-delay:.5s}.topic-card:nth-child(6){animation-delay:.6s}