Make visited link styles distinct
Please establish a different style (browsers typically style blue links as purple after they have been visited). This affects accessibility/usability, and should be updated for default rules. This is primarily intended to affect content links, and doesn't need to change navigation at this time (but that is also desirable).
Add new $link-color-visited variable: https://github.com/usgs/hazdev-template/blob/master/src/htdocs/css/_variables.scss And use it here: https://github.com/usgs/hazdev-template/blob/master/src/htdocs/css/_typography.scss#L84