Fix CSS linting errors introduced for firefox 145

As of firefox 145, we have new linting errors:

• stylelint-plugin-mozilla/use-font-weight-tokens
• stylelint-plugin-mozilla/use-border-radius-tokens
• stylelint-plugin-mozilla/use-font-size-tokens

and maybe some others.

I'll use my best judgement to replace them. Any unknowns that require UX, I'll implement a work-around and we can ask UX later rather than be blocked.