<svg xmlns="http://www.w3.org/2000/svg"
     xmlns:h="http://www.w3.org/1999/xhtml"
     xmlns:xlink="http://www.w3.org/1999/xlink"
     width="300" height="200" viewBox="0 0 300 200">
  <metadata>
    <h:link rel="help" href="https://svgwg.org/svg2-draft/styling.html#RequiredProperties"/>
    <h:link rel="match" href="transform-box-ref.svg"/>
    <h:meta name="assert" content="The transform-box property impacts SVG rendering."/>
  </metadata>

  <style>
    #r {
      fill: cyan;
      stroke: cyan;
      stroke-width: 8px;
      transform-box: fill-box;
      transform-origin: 75% 100%;
      transform: scale(2, 2);
    }
  </style>
  <g transform="translate(140, 130)">
    <rect id="r" x="0" y="0" width="40" height="10" />
  </g>
</svg>