SVG viewBox & coordinate system

https://codepen.io/xgqfrms/pen/abOOrjp


<html>
  <body>
    <header>
      <h1>user coordinate system / viewport coordinate system</h1>
      <p>（SVG 宽高）比 viewBox 大，就等比放大；比 viewBox 小，就等比缩小；</p>
    </header>
    <h2>width="400" height="200 viewbox="0 0 200 100"</h2>
    <p>2 : 1</p>
    <section>
      <svg width="400" height="200" viewbox="0 0 200 100">
        <!-- SVG content drawn onto the SVG canvas -->
        <rect fill="grey" x="0" y="0" width="200" height="100"/>
        <text x="100" y="50" fill="red">200 100</text>
      </svg>
    </section>
    <h2>width="400" height="200" viewbox="0 0 400 200"</h2>
    <p>1 : 1</p>
    <section>
      <svg width="400" height="200" viewbox="0 0 400 200">
        <!-- SVG content drawn onto the SVG canvas -->
        <rect fill="grey" x="0" y="0" width="200" height="100"/>
        <text x="100" y="50" fill="red">200 100</text>
      </svg>
    </section>
    <h2>width="200" height="100" viewbox="0 0 400 200"</h2>
    <p>1 : 2</p>
    <section>
      <svg width="200" height="100" viewbox="0 0 400 200">
        <!-- SVG content drawn onto the SVG canvas -->
        <rect fill="grey" x="0" y="0" width="200" height="100"/>
        <text x="100" y="50" fill="red">200 100</text>
      </svg>
    </section>
  </body>
</html>