♻️ Refactor: Use IIFE for background-blur and simplify code

This improves readability and removes an unnecessary function declaration by using IIFE.

This is inspired by #2262 . If both are merged, this would enhance consistency

Author: servedsmart

assets/js/background-blur.js

@@ -1,15 +1,10 @@
-function setBackgroundBlur() {
-  const scriptElement = document.currentScript;
-  const targetId =
-    scriptElement && scriptElement.getAttribute("data-target-id")
-      ? scriptElement.getAttribute("data-target-id")
-      : (console.error("data-target-id is null"), null);
+(() => {
+  const script = document.currentScript;
+  const targetId = script?.getAttribute("data-target-id");
 
   window.addEventListener("scroll", () => {
     const scroll = window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop || 0;
     const backgroundBlur = document.getElementById(targetId);
     backgroundBlur.style.opacity = scroll / 300;
   });
-}
-
-setBackgroundBlur();
+})();