How to use the Varaiable in HTML Style.md

How to use the Varaiable in HTML Style?

Codebase

<script>
  let size = 100;
</script>

<div style='--width_size:{size};'></div>

<style>
  div {
    width : calc( var(--width_size) * 1px );
  }
</style>

This works well for me. :-)