Fix button styling to restore proper appearance

- Remove overly aggressive CSS reset that was making buttons invisible
- Keep font inheritance but preserve .btn class background and border styling
- Fix 'did' button appearing white/invisible

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

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

src/index.css

@@ -33,10 +33,6 @@
     font-size: inherit;
     line-height: inherit;
     vertical-align: baseline;
-    margin: 0;
-    border: none;
-    background: none;
-    padding: 0;
   }
   
   .btn-sm {