Fix visual bug with hoverable buttons on FOI Guide page

[builderpepc]

See discussion on #80 (issue: #70). On screen widths >1600px, a white space begins to appear between the blue highlight and the black right-side edge of the buttons on the FOI Guide page in their on-hover state.

2025-07-07.01-31-49.mp4

Expected behavior shown here from Figma:

20250707-0543-14.3332594.mp4

Screen widths these large are uncommon, but because these buttons will likely be used on multiple pages in the future, it is worth looking into a fix for this visual bug.