index.html

<html>
    <head>
        <meta name="viewport" content="width=device-width, initial-scale=1">
        <title>Sorting visualization</title>
        <meta charset="utf-8">
        <link href="font-awesome.min.css" rel="stylesheet" type="text/css">
        <link href="main.css" rel="stylesheet" type="text/css">
    </head>
    <body>
        <div style="display:flex; align-items: top; margin: 20px;">
          <div>
            <canvas id="canvas">Your browser doesn't supports canvas.</canvas>
          </div>
          <div style="margin-left:20px;">
              <canvas id="canvas-2">Your browser doesn't supports canvas.</canvas>
              <div style="margin-top:10px">
                <a id="canvas-2-dl" href="#" download="canvas.png">Download</a>
              </div>
          </div>
        </div>
        <input type="file" id="image_upload" accept="image/*" style="visibility:hidden">
        <script src="https://d3js.org/d3.v4.min.js"></script>
        <script src="dat.gui.min.js"></script>
        <script src="sort.js"></script>
    </body>
</html>