My top reasons for using CSS:
- hiding back button
- reconfiguring of inline list fields (especially the card layout)
- making components sticky to top/bottom of screen
- manipulating the comments component to provide a more chat-like experience
- making video component “inline” and not full width
- adding badge/counts on top of inline list tiles or tab icons
- creating a modal overlay on a screen that forces a user to click a button before viewing content on that screen
- more than 4 columns for inline list > tiles
- choice component: scrolling chips (not stacked); making a choice component sticky so it can act like a screen filter