*,:before,:after{box-sizing:border-box;margin:0;padding:0}html,body{width:100%;height:100%;font-family:Segoe UI,system-ui,sans-serif;overflow:hidden}#app{color:#eee;background:#1a1a2e;flex-direction:column;width:100vw;height:100vh;display:flex}#topbar{z-index:10;background:#16213e;flex-shrink:0;justify-content:space-between;align-items:center;padding:8px 16px;display:flex}#topbar h1{font-size:18px;font-weight:600}#btnBack{cursor:pointer;font-size:14px}#timerDisplay{font-variant-numeric:tabular-nums;color:gold;font-size:18px;font-weight:700}.btn{cursor:pointer;border:none;border-radius:6px;padding:8px 20px;font-size:14px;transition:all .2s}.btn-primary{color:#fff;background:#e94560;font-weight:600}.btn-primary:hover{background:#d63850}.btn-text{color:#aaa;background:0 0}.btn-text:hover{color:#fff}.stage{flex:1;justify-content:center;align-items:center;display:flex;position:relative;overflow:hidden}#sceneCanvas{width:100%;height:100%}#sceneCanvas canvas{display:block;width:100%!important;height:100%!important}#loadingIndicator{color:#888;z-index:5;font-size:16px;position:absolute;top:50%;left:50%;transform:translate(-50%,-50%)}#controls,#puzzleControls{background:#16213e;flex-wrap:wrap;flex-shrink:0;justify-content:center;align-items:center;gap:16px;padding:12px 16px;display:flex}#difficultyGroup{gap:8px;display:flex}.diff-option{cursor:pointer;-webkit-user-select:none;user-select:none;background:#0f3460;border-radius:20px;padding:6px 14px;font-size:13px;transition:all .2s}.diff-option.selected{color:#fff;background:#e94560}.diff-option input{display:none}#puzzleCanvas{cursor:pointer;border-radius:4px;max-width:80vmin;max-height:80vmin;display:block}.overlay{z-index:100;background:#0009;justify-content:center;align-items:center;display:flex;position:fixed;inset:0}.overlay-content{text-align:center;background:#16213e;border-radius:12px;max-width:360px;padding:32px 40px}.overlay-content h2{color:gold;margin-bottom:8px;font-size:22px}.overlay-content p{color:#aaa;margin-bottom:20px;font-size:14px}.overlay-content .btn{margin:0 6px}.fail-overlay{z-index:200;background:#000000d9;justify-content:center;align-items:center;animation:1.5s fadeIn;display:flex;position:fixed;inset:0}.fail-text{color:#e94560;text-shadow:0 0 40px #e9456080;letter-spacing:4px;font-size:36px;font-weight:700}@keyframes fadeIn{0%{opacity:0}to{opacity:1}}