* { box-sizing: border-box; }
body { margin: 0; background: #111; overflow: hidden; }
#ui {
  position: absolute; bottom: 20px; left: 20px;
  background: rgba(0,0,0,0.72); border: 1px solid #2a2a2a;
  border-radius: 6px; padding: 12px 14px;
  font: 12px/1.6 monospace; color: #ccc; min-width: 210px;
}
#ui label { display: block; margin-bottom: 2px; color: #888; font-size: 11px; }
#ui input[type=range] { width: 100%; accent-color: #08c; margin: 3px 0 8px; }
#ui button {
  width: 100%; background: #1a3a28; border: 1px solid #2a6040;
  color: #6da; padding: 5px 10px; border-radius: 4px;
  cursor: pointer; font: 12px monospace;
  margin-top: 6px;
}
#ui button:hover { background: #245038; }
#ui button:disabled {
  background: #1b1b1b; border-color: #333; color: #666; cursor: default;
}