User-agent styles are the browser’s built-in CSS values for HTML elements when no later CSS overrides them. They provide a starting appearance before theme, site, or local styles apply. section 7.2.1 section 7.5
An h1 heading before author styling
A browser typically displays an h1 as a block element, twice the root font size, bold, with space above and below. It also uses black text unless a later stylesheet changes the color. section 7.2.1 section 7.2.5
User-agent styles occupy the first level of the cascade:
- Browser defaults establish the initial appearance of HTML elements. section 7.5
- A theme stylesheet can override those defaults across the site. section 7.2.5
- Additional CSS can override both browser defaults and theme styles. section 7.2.5
- Inline CSS overrides the earlier levels for a local element or content zone. section 7.2.5
<h1>MAJOR HEADLINE</h1>
Inspect the h1 markup that triggers the browser’s built-in heading defaults. section 7.2.1
