Calculate a margin using CSS percentage and unit together

Question

margin-left: 100 + 20%;

I want to do something the same as above. But CSS does not have any format. How can I successfully use these together ?

Answer 1

Without javascript? Only by wrapping that content into another element (usually <div>) and splitting that margin to two elements.

Something like:

<div style="margin-left:20%">
  <div style="margin-left:100px">
  <!-- content -->
  </div>
</div>