holmes.css – CSS Markup Detective

holmes.css is a stand-alone diagnostic CSS stylesheet that can highlight potentially invalid, inaccessible, or erroneous HTML and HTML5 markup by adding one class. The holmes.css file will display either an error (red outline), a warning (yellow outline), or a deprecated style (dark grey outline) for flags such as missing required attributes on tags, potentially improvable markup, deprecated and non-W3C elements and attributes, and others.

Core Features

• Highlights potentially invalid, inaccessible, or erroneous HTML and HTML5 markup
• Displays error, warning, or deprecated style for flags