Add breathing room: ~40-50% larger spacing throughout UI
- List row padding 14px → 18px, gap 12px → 16px
- Category card margin 10px → 16px, padding 16px → 20px
- Guide box margin 20px → 28px, padding 12px → 16px
- Gallery grid gap 14px → 18px
- Actions margin 22px → 28px, bottom-bar margin 18px → 24px
- Modal sidebar gap 16px → 20px
- Consistent 4px-scale spacing system