Style classes specific to the elements where they might sit with CSS.

Given this...

<h1 class="foo">bar</h1>
<ul class="foo">
   <li>baz</li>
   <li>qux</li>
</ul>

 
 

If we want to make the h1 tag red and the copy at the unordered list green we may do so like so:

h1.foo {
   color: #FF0000;
}
ul.foo {
   color: #00FF00;
}

 
 

This is another something I learned from "ASP.NET Core 2 and Angular 5" by Valerio De Sanctis. I thought it was strange that there was no space between the dot and the element tag beforehand at the CSS.