Who said CSS has no dynamic condition?

README.md

What do you think about that ? Is tricky or bad ?

It can be usefull to edit multiple css properties in javascript with just change a variable.

index.html

<div id="red"></div>
<div id="blue"></div>

<style>
	:root {
	  --TRUE: initial;
	  --FALSE: 0;
	  
	  --show-red: var(--TRUE);
	}

	#red {
	  /* Display block if TRUE else hide the div */
	  display: var(--show-red, block);
	  height: 50px;
	  width: 50px;
	  background-color: red;
	}

	#blue {
	  /* Make div height 50px if show red div else 100px */
	  height: calc((2 - var(--show-red, 1)) * 50px);
	  width: 50px;
	  background-color: blue;
	}
</style>