Cascading Style Sheets
Because ebooks are HTML files, they use CSS
HTML was intended to define the content of a document, with <h1>headings</h1>
and <p>paragraphs</p>
HTML was not intended to contain formatting for the document.
When <font> tags, and colour attributes were added to the HTML specification,
developing large web sites, where fonts and colour information were added to
every page, became a nightmare.
To solve this problem, the World Wide Web Consortium (W3C) created CSS. From
HTML 4.0, all formatting could be removed from the HTML document and stored in a
separate CSS file. All browsers support CSS.
Now, CSS defines how HTML elements are displayed. So external style sheets
enable you to change the appearance and layout of all the pages in a Web site by
editing the CSS file.
All you need to know
The conversion software constructs the CSS file for you. When you use Sigil
you can see the styles that are being applied. If you have many (20+) styles,
your source file was a mess! If you have a clean file there will not be many
styles as the text paragraphs will all use the same style.
You can try tweaking the CSS file - Use search & replace to remove styles you
do not like from the HTML file(s) and replace them with one that you like.
But this is complicated and because CSS is so powerful then take care.
