Code editor change UI of CABLES

I create simple project with Ops.Html.CSS_v2 class. Put simple code to customize SPAN element and focus color for DIV.

span
{
color:white;
font-size: 20px;
line-height:18px;
}

div:focus {
background-color: yellow;
}

And this code control full UI of CABLES. If I change font size in a code it’s change UI font size too. And if I focus on some div, color is changing too. U can see it on image/