v1.0.2: Complete CSS refactoring with custom properties

- Introduced comprehensive CSS custom properties for colors, fonts, and transitions
- Eliminated 40+ hardcoded color values with centralized variables
- Consolidated duplicate font family definitions
- Removed redundant button styles and input styling
- Optimized theme system with consistent property usage
- Fixed accessibility issue with MIT license link
- Reduced code redundancy while maintaining full functionality
- All themes (auto/light/dark) now use unified variable system

src/App.js

@@ -391,7 +391,7 @@ function App() {
             </div>
             <div className="col-md-6 text-md-end">
               <p className="mb-0 text-muted small">
-                Licensed under <a href="#" className="text-decoration-none">MIT License</a> | 
+                Licensed under <a href="https://opensource.org/licenses/MIT" target="_blank" rel="noopener noreferrer" className="text-decoration-none">MIT License</a> | 
                 <a href="https://jmespath.org/" target="_blank" rel="noopener noreferrer" className="text-decoration-none ms-2">
                   Learn JMESPath
                 </a>