Problem/Motivation
#3261049: Remove duplicated margin properties from typography CSS discovered some redundant CSS. There is a Stylelint rule declaration-block-no-duplicate-properties that can detect this situation for us.
Enabling the rule now notes lots of duplicate background-image rules, which can be solved by #3265596: Remove obsolete -webkit-linear-gradient CSS
Steps to reproduce
Proposed resolution
Solve #3261049: Remove duplicated margin properties from typography CSS and #3265596: Remove obsolete -webkit-linear-gradient CSS first.
Enable the rule and fix any remaining cases.
