 {
        font-family: monospace;
        padding: 1em;
        border: 1pt solid #ddd;
        white-space: pre;
      }
      code .error { font-weight: bold; color: red; }
      code .warning { font-weight: bold; color: darkgoldenrod; }
      code .field { color: blue; }
      code .string { color: cyan; }
    </style>
  </head>
  <body>
    <h1>RCL Playground</h1>
    <h2>Input</h2>
    <p id="input" contenteditable="true" plaintext-only="true">[for x in std.range(0, 3): { id = x, name = f"item-{x}" }]