title: Css,Js how to convert a number to the animaition time
body: <p>At first, I try to use</p>
  <pre><code>--Time: 0.1s;
  animation-delay:--Time;
  </code></pre>
  <p>But this don't work, it only work when</p>
  <pre><code>animation-delay:0.1s;
  </code></pre>
  <p>Why and how to solve this problem?</p>