@import url("https://fonts.googleapis.com/css2?family=Source+Serif+4:ital,wght@0,400;0,600;0,700;1,400&family=Fira+Code:wght@400;500&display=swap");*{box-sizing:border-box}body,html{margin:0;padding:0;width:100%;height:100%;background:#0d1117;color:var(--text-primary);font-family:var(--font-primary)}:root{--bg-gradient:linear-gradient(150deg,#0d1117,#161b22 50%,#21262d);--text-primary:#e6edf3;--text-secondary:rgba(230,237,243,.7);--font-primary:"Source Serif 4",Georgia,serif;--font-mono:"Fira Code",monospace;--color-primary:#88c0d0;--color-primary-dark:#81a1c1;--color-accent:#b48ead;--color-success:#a3be8c;--color-error:#bf616a;--color-warning:#ebcb8b;--title-gradient:linear-gradient(135deg,#88c0d0,#81a1c1 50%,#b48ead);--container-max-width:900px;--container-padding:40px 20px}.viz-page-container{min-height:100vh;background:var(--bg-gradient);font-family:var(--font-primary);color:var(--text-primary);padding:var(--container-padding)}.viz-content-container{max-width:var(--container-max-width);margin:0 auto}.viz-title{font-size:2.5rem;font-weight:700;text-align:center;margin-bottom:8px;background:var(--title-gradient);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.viz-subtitle{text-align:center;opacity:.7;margin-bottom:32px;font-size:1.1rem}.math{background:rgba(136,192,208,.15);padding:2px 6px;border-radius:4px}.math,.math-text{font-family:var(--font-mono);font-size:.9em}.proof-box{background:linear-gradient(135deg,rgba(136,192,208,.1),rgba(129,140,248,.1));border:1px solid rgba(136,192,208,.3);border-radius:12px;padding:24px;margin:20px 0}.definition-box{background:hsla(0,0%,100%,.05);border-left:4px solid var(--color-primary);padding:20px 24px;margin:24px 0;border-radius:0 8px 8px 0}.visualization-container{background:rgba(0,0,0,.4);border-radius:16px;padding:32px 24px;margin-top:24px}.btn{background:linear-gradient(135deg,var(--color-primary) 0,var(--color-primary-dark) 100%);border:none;color:#0d1117;padding:12px 24px;border-radius:8px;font-family:inherit;font-weight:600;font-size:.95rem;cursor:pointer;transition:all .3s ease;margin:4px}.btn:hover{transform:translateY(-2px);box-shadow:0 8px 24px rgba(136,192,208,.3)}.btn.secondary{background:transparent;border:2px solid rgba(136,192,208,.5);color:var(--color-primary)}.btn.secondary:hover{background:hsla(0,0%,100%,.1);border-color:rgba(136,192,208,.7)}.btn:disabled{opacity:.5;cursor:not-allowed;transform:none}.btn.active{background:linear-gradient(135deg,var(--color-primary) 0,var(--color-primary-dark) 100%);color:#0d1117}.step-nav{display:flex;gap:4px;justify-content:center;flex-wrap:wrap;margin:20px 0}.step-btn{width:36px;height:36px;border-radius:50%;border:2px solid rgba(136,192,208,.4);background:transparent;color:var(--color-primary);font-family:var(--font-mono);font-size:.85rem;cursor:pointer;transition:all .3s ease}.step-btn:hover{background:rgba(136,192,208,.2);transform:scale(1.1)}.step-btn.active{background:var(--color-primary);color:#0d1117;border-color:var(--color-primary)}.step-indicator{display:flex;gap:8px;justify-content:center;margin:20px 0}.step-dot{width:12px;height:12px;border-radius:50%;background:hsla(0,0%,100%,.2);cursor:pointer;transition:all .3s ease}.step-dot.active{background:var(--color-primary);transform:scale(1.3)}.card{background:hsla(0,0%,100%,.05);border-radius:12px;padding:24px;transition:all .3s ease;cursor:pointer;border:2px solid transparent}.card:hover{background:hsla(0,0%,100%,.08);transform:translateY(-4px);box-shadow:0 8px 24px rgba(0,0,0,.3)}.card.open-card{border-color:var(--color-primary)}.card.closed-card{border-color:var(--color-error)}.card.neither-card{border-color:var(--color-accent)}.legend-box{display:inline-flex;align-items:center;gap:8px;background:rgba(0,0,0,.3);padding:6px 12px;border-radius:6px;margin:4px;font-size:.85rem}@keyframes fadeIn{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}@keyframes pulse{0%,to{transform:scale(1);opacity:1}50%{transform:scale(1.2);opacity:.8}}@keyframes pulseOpacity{0%,to{opacity:.6}50%{opacity:1}}@keyframes slideIn{0%{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}@keyframes shrink{0%{stroke-dashoffset:0}to{stroke-dashoffset:100}}.interval-animate{animation:fadeIn .5s ease forwards}.point-pulse{animation:pulse 1.5s ease-in-out infinite}.pulse{animation:pulseOpacity 2s ease-in-out infinite}.slide-in{animation:slideIn .5s ease-out}svg{width:100%;height:auto}svg .grid-pattern{fill:url(#grid)}.text-center{text-align:center}.text-gray-700,.text-gray-800{color:var(--text-primary)}.text-gray-600{color:var(--text-secondary)}.text-gray-500{color:rgba(148,163,184,.9)}.text-xs{font-size:.75rem}.text-sm{font-size:.875rem}.font-semibold{font-weight:600}.fill-gray-600{fill:#e5e7eb}.fill-gray-500{fill:#9ca3af}.fill-gray-400{fill:#cbd5f5}.fill-blue-600{fill:#60a5fa}.fill-purple-600{fill:#a855f7}.fill-amber-600{fill:#d97706}.fill-green-600{fill:#16a34a}.fill-red-600{fill:#dc2626}.fill-cyan-600{fill:#0891b2}.fill-cyan-700{fill:#0e7490}.text-primary{color:var(--color-primary)}.text-success{color:var(--color-success)}.text-error{color:var(--color-error)}.text-warning{color:var(--color-warning)}.opacity-70{opacity:.7}.opacity-80{opacity:.8}