refactor: improve layout ratios and pagination UI

Layout improvements:
- Fixed header/main/footer ratios to 2:5, 3:5, 1:5 using flex
- Default to sans-serif font system stack
- Made sections properly flex-based instead of viewport height

Pagination improvements:
- First/previous/next/last navigation buttons (‹‹ ‹ › ››)
- Current page highlighted in colored badge
- Disabled state for unavailable actions
- Clean rounded button design with hover effects
- Proper spacing and visual hierarchy

Card styling:
- Better typography hierarchy
- Hover effects (lift + shadow)
- Improved spacing and readability
- Year displayed in brand color

Tests passing ✅

src/cache/rate_limit/ad921d60486366258809553a3db49a4a.json

@@ -1 +1 @@
-[1770895586]
+[1770895832]

src/cache/rate_limit/f528764d624db129b32c21fbca0cb8d6.json

@@ -0,0 +1 @@
+[1770895784,1770895787]