Cell background color is not applied properly on mobile table component

**Describe the bug**
While working on table using [Table / Mobile card](https://vanillaframework.io/docs/examples/patterns/tables/table-mobile-card) for ubuntu.com/pro.

Bug found here :

This needs to look like this :

I noticed when the background color is applied to `td`, the entire `td` cell background does not change because of the `tr` padding. I had to use custom styles locally to fix this. Should this be fixed in vanilla for future use? What do you think?

Start with the Table / Mobile card example linked in the issue and inspect how padding on the mobile table's tr interacts with background colors applied to td. Compare the current rendering with the expected screenshot, then verify that the full cell background is covered without breaking the mobile table layout.

Written by the indexing model from the issue text.