About
The origin and sorting order of CSS helps browsers to determine which rules win out over others. When one of those methods completely fails, there is a conflict as to which CSS rule should be applied.
CSS has in place a way to deal with those conflicts: the specificity of the CSS selector. The higher the specificity of a CSS selector, the greater the likelihood its declarations are used over another CSS rule's declarations.
This reference was formerly hosted at cssspecificty.com, which went offline long ago. This was Alice's favourite reference for this, so she's restored the content, modernized it according to her taste in HTML, and made it available within a GitHub repository, hosted under specificity.webcore.io. Links to relevant Mozilla Developer Network pages have also been added.