<!DOCTYPE html>
<title>CSS aspect-ratio reference: svg in img</title>
<style>
  img {
    width: 200px;
    height: 100px;
    padding-top: 50px;
  }
</style>
<img src='data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 200 100"><rect fill="red" stroke="black" stroke-width="6" width="200" height="100"/></svg>'/>
