RE: [css-variables] Remaining Issues

> What does the 'possibility of replacing normal properties' mean? And why
> is it very important?

A property replace another if, instead of changing that second property, you change the other to achieve a similar effect.

Example:

   var-col-size: 33%;
   var-col-index: 1;
   position: absolute;
   left: get(var-col-index * var-col-size);

If I want to animate my layout, and add a fourth column inside an animation, or change an element of column inside an animation, I may want to transition 'var-col-index' from 1 to 2, or change the 'var-col-size' property in order to create an anim where the colsize increases from 0 to 33% at the opening of the page.

If custom properties are not animatable, I think I'll consider them 'completely broken', down from my current 'they are broken' vision.