body { margin:0; background:#ffffff; color:#000000; font-family: system-ui, Arial; overflow:hidden; }
    #ui {
      position: absolute; left: 12px; top: 12px; z-index: 20;
      background: rgba(255, 255, 255); padding:10px; border-radius:8px;
      display:flex; gap:10px; align-items:center;
    }
    button { background:#ffffff; color:#000000; border:1px solid #444; padding:8px 10px; border-radius:6px; cursor:pointer; }
    button.active { background:#2a8; color:rgb(255, 255, 255); border-color:#7df; font-weight:600; }
    #status { position:absolute; right:12px; top:12px; z-index:20; background:rgba(255, 255, 255); padding:8px 10px; border-radius:8px; }
    canvas{ display:block; }