SVG

Links

http://svgpocketguide.com/book/
Example

<!DOCTYPE html>
<html>
  <head>
    <style media="screen">
      body, html {
        height: 100%;
        background: #eee;
      }
      body {
        display: flex;
        align-items: center;
        justify-content: center;
      }
      rect {
        fill: #cc0000;
        stroke: black;
        stroke-width: 2;
      }
    </style>
  </head>
  <body>
    <svg width="290" height="270">
      <rect x="10" y="10" width="30" height="250" />
      <rect x="50" y="110" width="30" height="150" />
      <rect x="90" y="60" width="30" height="200" />
      <rect x="130" y="140" width="30" height="120" />
      <rect x="170" y="30" width="30" height="230" />
      <rect x="210" y="80" width="30" height="180" />
      <rect x="250" y="50" width="30" height="210" />
    </svg>
  </body>
</html>