[Jellby]

Basic CSS+HTML.

Say your CSS has a style that says:

.calibre1 { color: red }

and now you want that style to apply to all <h1> elements too, i.e., you want all your <h1> to be red. You can either manually add the "calibre1" class to all your <h1>:

<h1 class="calibre1">Chapter 1</h1>

or add the h1 selector to the style:

.calibre1, h1 { color: red }

(the latter means that "color: red" applies to anything with class="calibre1", and to every <h1>.)

Of course, if you don't have anything with class="calibre1", you can just remove it and leave the style for h1 only:

h1 { color: red }