feat: enhance CSS handling and optimize global styles

- Enabled PostCSS nesting with specific configuration for modern compatibility
- Added global CSS reset for consistent tap highlights across browsers
- Optimized package configuration for broader browser support
- Refactored and streamlined global CSS, removing redundant styles for better maintainability
- Integrated additional CSS import in component for modular styling approach

package.json

@@ -47,5 +47,8 @@
   },
   "lint-staged": {
     "*": "eslint --fix"
-  }
+  },
+  "browserslist": [
+    "defaults"
+  ]
 }