This shows how to use Shazzer to fuzz CSS syntax. This vector uses an inline style and div to set the colour. JavaScript is executed directly after each fuzz to check getComputedStyle to see if the div is red.
<style>
$[chr]div{color:red;}
</style>
<div id=x>test</div>
window.getComputedStyle(x).color === 'rgb(255, 0, 0)' && log($[i])<style>
0x09div{color:red;}
</style>
<div id=x>test</div>
<style>
div{color:red;}
</style>
<div id=x>test</div>
<style>
0x0Cdiv{color:red;}
</style>
<div id=x>test</div>
<style>
div{color:red;}
</style>
<div id=x>test</div>
<style>
div{color:red;}
</style>
<div id=x>test</div>