ke-width: 6px;
        fill: none;
        opacity: 0.6;
      }
      .message {
        fill: #00ffff;
        filter: drop-shadow(0 0 4px rgba(0, 255, 255, 0.7));
        opacity: 0;
      }
    </style>
  </head>
  <body>
    <svg id="dataflow" width="800" height="400"></svg>
    <script>
      const svg = d3.select("#dataflow");
      const width = 800;
      const height = 400;

      // Create grid
      const gridSize = 20;
      const xGrid = d3.range(0, width, gridSize);
      const yGrid = d3.ran