To use custom CSS in Obsidian, go to Settings > Appearance, scroll down to CSS snippets, enable it, and then place your .css files in the snippets folder that appears. Obsidian will automatically ...

Typing utility TextExpander has been updated adding CSS Snippets and fixing several bugs.

Check your CSS code without leaving the IDE by using CssCop, which brings the CSS Lint functionality to the Visual Studio environment.

If you write code, you probably reuse blocks of it. Whether you're working in HTML, CSS, AppleScript, Objective-C ... it's all code, and a really well-written chunk of it deserves to be used again ...