# CSS Customization

While editing the book's cover page, you can include custom CSS into the Custom CSS field, which will be applied to all chapters in the book.

This is powerful and can have undesired effects because the CSS is applied to the entire page (not just the chapter contents). To prevent CSS from changing site formatting unexpectedly, you should limit your adjustments to only apply to content within the div#chapter-container id as follows:

div#chapter-container h2 { color: pink; } // Makes all H2 headings pink

## Snippets

These are some snippets that can be adjusted to add elements in a chapter or across an entire book.

### Banner Image

This snippet places an image above the main heading.

div#chapter-container h1 {    background-image: url("https://edtechbooks.org/images/logo.png");    background-repeat: no-repeat;    background-position: top right;    padding-top: 140px;    background-size: 100px;}

## Tooltips Bolded

This snippet makes all tooltips (e.g., glossary pop-ups) bolded.

div#chapter-container [data-toggle=tooltip] {     font-weight: bold;}

CC BY: This work is released under a CC BY license, which means that you are free to do with it as you please as long as you properly attribute it.