Description

• Improve cads UI by adding better contrast in the border, adding color and slightly increasing border width

Testing Instructions

1. Pull and checkout the branch fix/cards-borders
2. Build and run the extension: npm run build:all && npm run dev:ext
3. Open Privacy Sandbox tab on DevTools
4. Go any landing page that contains cards: Dashboard, Learning, Tracking Protection, Private Advertising, Site Boundaries
5. Observe that the cards have a colored border and they look consistent in all pages

Screenshot/Screencast

• Light theme:

• Dark theme:

Checklist

• I have thoroughly tested this code to the best of my abilities.
• I have reviewed the code myself before requesting a review.
• [NA] This code is covered by unit tests to verify that it works as intended.
• The QA of this PR is done by a member of the QA team (to be checked by QA).