The Stylesheets you add to your web page aren’t the only ones the browser applies. There are different types, or origins, of stylesheets. Yours are called authors stylesheets; There are also user agent styles, which are the browser’s default styles. - Use agent styles have lower priority, so your styles override them. - Some browsers let users define a user stylesheet. User stylesheets are rarely used and beyond your control, so I’ve left them out for simplicity.
There is an exception to the style origin rules: declarations that are marked as important. A declaration can be marked important by adding !important to the end of the declaration, before the semicolon:
Color: red !important;
Declarations marked !important are treated as a higher-priority origin, so the order of preference, in decreasing order, is this:
1. Author important
2. Author
3. User Agent