:root{--bg: #0f0f1a;--bg-card: #1a1a2e;--bg-surface: #16213e;--text: #e0e0e0;--text-muted: #8888aa;--primary: #6c63ff;--primary-hover: #5a52d5;--accent: #ff6584;--win: #4ecca3;--lose: #ff6b6b;--draw: #ffd93d;--border: #2a2a4a}*,*:before,*:after{box-sizing:border-box;margin:0}body{background:var(--bg);color:var(--text);font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;min-height:100vh;display:flex;align-items:center;justify-content:center}#app{max-width:960px;width:100%;padding:2rem}.screen{display:none}.screen.active{display:flex;flex-direction:column;align-items:center;gap:1.5rem}.screen-title{font-size:2.5rem;font-weight:800;background:linear-gradient(135deg,var(--primary),var(--accent));-webkit-background-clip:text;background-clip:text;color:transparent}.screen-subtitle{color:var(--text-muted);font-size:1.1rem}.btn{padding:.75rem 2rem;border-radius:12px;border:none;font-size:1rem;font-weight:600;cursor:pointer;transition:all .2s;background:var(--primary);color:#fff}.btn:hover{background:var(--primary-hover);transform:translateY(-2px)}.btn:active{transform:translateY(0)}.btn--secondary{background:transparent;border:2px solid var(--border);color:var(--text)}.btn--small{padding:.4rem 1rem;font-size:.85rem}.webcam-container{position:relative;width:640px;max-width:100%;aspect-ratio:4 / 3;border-radius:16px;overflow:hidden;border:2px solid var(--border);background:#000}.webcam-container video{width:100%;height:100%;object-fit:cover;transform:scaleX(-1)}.webcam-container canvas{position:absolute;top:0;left:0;width:100%;height:100%;transform:scaleX(-1)}.gesture-label{position:absolute;bottom:1rem;left:50%;transform:translate(-50%);background:#000000b3;color:#fff;padding:.5rem 1.5rem;border-radius:8px;font-size:1.2rem;font-weight:600}.game-area{display:grid;grid-template-columns:1fr 200px 1fr;gap:1.5rem;align-items:center;width:100%}.player-side,.ai-side{display:flex;flex-direction:column;align-items:center;gap:1rem}.vs-area{display:flex;flex-direction:column;align-items:center;gap:.5rem}.scoreboard{display:flex;gap:2rem;justify-content:center;background:var(--bg-card);padding:1rem 2rem;border-radius:12px;border:1px solid var(--border)}.score-item{text-align:center}.score-value{font-size:2rem;font-weight:800}.score-label{font-size:.8rem;color:var(--text-muted);text-transform:uppercase}.countdown-display{font-size:5rem;font-weight:900;color:var(--primary);animation:countdownPulse .8s ease;text-align:center}@keyframes countdownPulse{0%{transform:scale(1.3);opacity:.5}to{transform:scale(1);opacity:1}}.ai-hand{font-size:6rem;transition:transform .3s;text-align:center}.ai-hand--reveal{animation:aiReveal .5s ease-out}@keyframes aiReveal{0%{transform:scale(0) rotate(-180deg)}to{transform:scale(1) rotate(0)}}.result-banner{font-size:3rem;font-weight:900;padding:1rem 3rem;border-radius:16px;animation:resultAppear .4s ease-out}.result-banner--win{background:var(--win);color:#000}.result-banner--lose{background:var(--lose);color:#fff}.result-banner--draw{background:var(--draw);color:#000}@keyframes resultAppear{0%{transform:scale(.5);opacity:0}to{transform:scale(1);opacity:1}}.flash-overlay{position:fixed;top:0;left:0;width:100%;height:100%;pointer-events:none;z-index:100;animation:flash .5s ease-out forwards}.flash-overlay--win{background-color:#4ecca34d}.flash-overlay--lose{background-color:#ff6b6b4d}@keyframes flash{0%{opacity:1}to{opacity:0}}.mode-select{display:flex;gap:.5rem;flex-wrap:wrap;justify-content:center}.mode-select .btn{min-width:120px}.calibration-cards{display:flex;gap:1.5rem;flex-wrap:wrap;justify-content:center}.calibration-card{background:var(--bg-card);border:2px solid var(--border);border-radius:12px;padding:1.5rem;text-align:center;min-width:150px;transition:all .3s}.calibration-card--detected{border-color:var(--win);box-shadow:0 0 20px #4ecca34d}.calibration-card .gesture-emoji{font-size:4rem}.calibration-card .gesture-name{font-weight:600;margin-top:.5rem}.audio-controls{position:fixed;top:1rem;right:1rem;display:flex;align-items:center;gap:.5rem;background:var(--bg-card);padding:.5rem 1rem;border-radius:8px;border:1px solid var(--border);z-index:50}.volume-slider{width:80px;accent-color:var(--primary)}.mute-btn{background:none;border:none;color:var(--text);cursor:pointer;font-size:1.2rem}.round-history{display:flex;gap:.25rem;justify-content:center}.round-dot{width:12px;height:12px;border-radius:50%}.round-dot--win{background:var(--win)}.round-dot--lose{background:var(--lose)}.round-dot--draw{background:var(--draw)}.modal-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:#000000b3;display:flex;align-items:center;justify-content:center;z-index:200}.modal{background:var(--bg-card);border-radius:16px;padding:2rem;max-width:500px;width:90%;max-height:80vh;overflow-y:auto;border:1px solid var(--border)}.modal h2{margin-bottom:1rem}.modal p{color:var(--text-muted);margin-bottom:.75rem;line-height:1.6}.stats-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(120px,1fr));gap:1rem;width:100%}.stat-card{background:var(--bg-surface);border-radius:8px;padding:1rem;text-align:center}.stat-card .stat-value{font-size:1.8rem;font-weight:800;color:var(--primary)}.stat-card .stat-label{font-size:.75rem;color:var(--text-muted);text-transform:uppercase}@media (prefers-reduced-motion: reduce){*,*:before,*:after{animation-duration:.01ms!important;transition-duration:.01ms!important}}@media (prefers-contrast: more){:root{--bg: #000;--text: #fff;--border: #fff}}@media (max-width: 768px){.game-area{grid-template-columns:1fr}.webcam-container{width:100%}}