refactor(homepage): tighten mini abacus vertical padding

Reduced vertical padding from token '5' to '4' in the "Read and set
numbers" card icon container for better visual balance.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

apps/web/src/app/page.tsx

@@ -370,7 +370,7 @@ export default function HomePage() {
                               textAlign: 'center',
                               bg: 'rgba(255, 255, 255, 0.1)',
                               borderRadius: 'lg',
-                              py: i === 0 ? '5' : '2',
+                              py: i === 0 ? '4' : '2',
                               px: i === 0 ? '3' : '2',
                             })}
                           >