postcss-attribute-case-insensitive is a PostCSS plugin that enhances CSS attribute selectors to be case-insensitive. It achieves this by automatically applying a polyfill using advanced CSS selectors when necessary. This ensures that selectors like [data-attribute="value" i] are consistently interpreted across browsers, improving cross-browser compatibility for case-insensitive attribute matching without requiring manual additions to your CSS. Simplifies writing and maintaining robust CSS.