Reference contract: widget cards carry their own 15px padding and
.widget-content is bare. The added 20px padding inset every widget
card from the content max width on the fixed homepage (the only
bundle loading sidebar.css).
- drop the root padding rule and the unreferenced --flush modifier
- drop the now-redundant user-widget padding:0 workaround
- drop the dead --card-padding-lg token
- lock the contract with negative assertions in the display test
kate522