Match reference plugin structure and styling

- Updated main plugin file to match reference plugin structure
- Fixed CSS class naming to consistently use seoprostack prefix
- Updated JavaScript selectors to match CSS classes
- Restored original plugin functionality while maintaining new naming conventions
- Ensured exact match with reference plugin appearance and behavior

admin/js/seoprostack-admin.js

@@ -46,7 +46,7 @@ jQuery(document).ready(function($) {
         });
     }
         // Toggle sections
-        $('.seoprostack-toggle-header').on('click', function() {
+    $('.seoprostack-toggle-header').on('click', function() {
             $(this).toggleClass('active');
             $(this).next('.seoprostack-toggle-settings').slideToggle(300);
         });