Email-Safe CSS Inliner
Inline simple <style> rules into style attributes so HTML email renders consistently across clients.
Overview
Merges declarations from simple <style> selectors (element, class, id, and comma lists) into inline style attributes on matching elements, which is essential for consistent HTML email rendering. Existing inline styles take precedence and are not duplicated, while @media and @font-face rules are preserved in a retained <style> block. Built for email developers; it is regex-based, so use simple selectors.