Fix modal overlay issue and improve modal structure

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

app/javascript/controllers/event_duplication_controller.js

@@ -9,13 +9,6 @@ export default class extends Controller {
   connect() {
     // Get modal element from the document
     this.modalElement = document.querySelector('[data-event-duplication-target="modal"]')
-    
-    // Close modal when clicking outside
-    this.modalElement.addEventListener('click', (event) => {
-      if (event.target === this.modalElement) {
-        this.close()
-      }
-    })
   }
 
   open() {