:root {
          color-scheme: dark;
      }

      * {
          box-sizing: border-box;
      }

      html,
      body {
          height: 100%;
          margin: 0;
      }

      body {
          font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
          background: #0b0d10;
          color: #e6edf3;
      }

      header {
          display: flex;
          gap: .75rem;
          align-items: center;
          padding: .75rem 1rem;
          border-bottom: 1px solid #1f2328;
          background: #0f1216;
          position: sticky;
          top: 0;
          z-index: 10;
      }

      header h1 {
          margin: 0;
          font-size: 1.1rem;
          font-weight: 600;
      }

      .spacer {
          flex: 1;
      }

      .btn {
          background: #1f6feb;
          border: none;
          color: white;
          padding: .45rem .7rem;
          border-radius: .5rem;
          cursor: pointer;
      }

      .btn:disabled {
          opacity: .6;
          cursor: default;
      }

      .muted {
          color: #9aa5b1;
          font-size: .9rem;
      }

      input[type="number"] {
          background: #0b0d10;
          border: 1px solid #30363d;
          color: #e6edf3;
          border-radius: .4rem;
          padding: .2rem .4rem;
      }

      input[type="range"] {
          width: 12rem;
      }

      #root {
          height: calc(100% - 54px);
      }

      #stage {
          width: 100%;
          height: 100%;
      }

      canvas {
          display: block;
             width: 100%;
      }