*{box-sizing:border-box}html,body{height:100%;margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,Helvetica Neue,Arial}#canvas-container{position:fixed;top:0;right:0;bottom:0;left:0}canvas{display:block;width:100%;height:100%}#ui{position:fixed;left:12px;top:12px;z-index:3}.topbar{background:#0a0a0cb3;color:#fff;padding:10px;border-radius:8px}.topbar h1{margin:0 0 6px;font-size:16px}.controls{display:flex;gap:8px;align-items:center}.controls input{width:80px}