Separate Content/Functionality from Visual Design
Accessibility of web page content and functionality occurs almost entirely in page markup (HTML). Cascading Style Sheets (CSS), on the other hand, should be used exclusively for defining page styling and visual design. While CSS can be used to improve visual design, accessibility, and usability, screen readers ignore nearly all styles. When page content or functionality are integrated into visual design and CSS (such as a CSS background image that presents content, or a styled button that presents no functional text), then this content is not available to screen reader users. Ensure that content and/or functionality are not lost when page styles are disabled.
