title: calc in linear gradient does not work in IE/Edge
body: <p>IE and Edge do not seem to be able to calculate the height correctly in this gradient. Does anyone have a solution?</p>
  
  <pre><code>background: linear-gradient(180deg, rgba(255,255,255,0) 100px, #f5f5f5 100px, #f5f5f5 calc(100% - 100px), rgba(255,255,255,0) calc(100% - 100px));
  </code></pre>