For the visual presentation of blocks of text, a mechanism is available to achieve the following:
- Foreground and background colors can be selected by the user.
- Width is no more than 80 characters or glyphs (40 if CJK).
- Text is not justified (aligned to both the left and the right margins).
- Line spacing (leading) is at least space-and-a-half within paragraphs, and paragraph spacing is at least 1.5 times larger than the line spacing.
- Text can be resized without assistive technology up to 200 percent in a way that does not require the user to scroll horizontally to read a line of text on a full-screen window.
Offer users the ability to control foreground and background colours, line spacing, and width of blocks of text.
Supports readability and customisation for users with visual or cognitive disabilities.
If you theme the website normally, the browsers should be able to override the site styles. This can be tested at least with Firefox: Change the fonts and colors websites use on Mozilla's support site.