body {
      font-family: sans-serif;
      margin: 24px;
      background: #f4f6f8;
    }
    canvas {
      border: 2px solid #888;
      background: #fff;
      display: block;
      margin: 0 auto 24px;
    }
    .controls {
      display: flex;
      justify-content: center;
      gap: 40px;
      flex-wrap: wrap;
    }
    .panel {
      background: #fff;
      border: 1px solid #ccc;
      padding: 16px;
      border-radius: 8px;
      width: 220px;
      box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    }
    .panel h3 {
      margin-top: 0;
      color: #0078d4;
    }
    .input-row {
      margin-bottom: 12px;
      text-align: center;
    }


    input[type="number"],
    input[type="checkbox"] {
      font-size: 14px;
    }
    input[type="number"] {
      width: 80px;
      padding: 6px;
      font-size: 14px;
      text-align: center;
      margin-top: 4px;
    }

    .btns {
      display: flex;
      gap: 8px;
      margin-bottom: 12px;
    }
    button {
      flex: 1;
      padding: 6px;
      font-size: 14px;
      background: #0078d4;
      color: white;
      border: none;
      border-radius: 4px;
      cursor: pointer;
    }
    button:hover {
      background: #005a9e;
    }