:visited is a pseudo class selector used for anchor link elements that matches when the href attribute of that anchor link has been visited in the past by this browser. It is meant to be useful feedback for a user, so they can tell the difference between links they have been to and links they have not.
There have been some security concerns about
:visited, namely that a malicious website could have links to tons and tons of websites and have
:visited links and what styling information can be reported.
As part of that security stuff, there are limits to what kind of styling a visited link can get. Specifically:
border-color(and its sub-properties)
- The color parts of the