diff --git a/xExtension-QuickCollapse/static/script.js b/xExtension-QuickCollapse/static/script.js
index b99f846..93b3196 100644
--- a/xExtension-QuickCollapse/static/script.js
+++ b/xExtension-QuickCollapse/static/script.js
@@ -1,8 +1,9 @@
 (function () {
     function toggleCollapse() {
-        var streamElem = document.getElementById('stream');
-        var toggleElem = document.getElementById('toggle-collapse');
-        var wasCollapsed = streamElem.classList.contains('hide_posts');
+        const streamElem = document.getElementById('stream');
+        const toggleElem = document.getElementById('toggle-collapse');
+        const wasCollapsed = streamElem.classList.contains('hide_posts');
+
         if (wasCollapsed) {
             streamElem.classList.remove('hide_posts');
             toggleElem.classList.remove('collapsed');
@@ -12,7 +13,10 @@
         }
 
         if (context.does_lazyload && wasCollapsed) {
-            streamElem.querySelectorAll('img[data-original], iframe[data-original]').forEach(function (el) {
+            const lazyloadedElements = streamElem.querySelectorAll(
+                'img[data-original], iframe[data-original]'
+            );
+            lazyloadedElements.forEach(function (el) {
                 el.src = el.getAttribute('data-original');
                 el.removeAttribute('data-original');
             });
@@ -25,7 +29,7 @@
             return setTimeout(syncWithContext, 10);
         }
 
-        var toggleElem = document.getElementById('toggle-collapse');
+        const toggleElem = document.getElementById('toggle-collapse');
         toggleElem.title = quick_collapse_vars.i18n.toggle_collapse;
         toggleElem.innerHTML = `<img class="icon uncollapse" src="${quick_collapse_vars.icon_url_out}" alt="↕" />`;
         toggleElem.innerHTML += `<img class="icon collapse" src="${quick_collapse_vars.icon_url_in}" alt="✖" />`;
@@ -35,23 +39,23 @@
         }
     }
 
-    var streamElem = document.getElementById('stream');
+    const streamElem = document.getElementById('stream');
     if (!streamElem || !streamElem.classList.contains('normal')) {
         // The button should be enabled only on "normal" view
         return;
     }
 
     // create the new button
-    let toggleElem = document.createElement('button');
+    const toggleElem = document.createElement('button');
     toggleElem.id = 'toggle-collapse';
     toggleElem.classList.add('btn');
     toggleElem.addEventListener('click', toggleCollapse);
 
-    // replace the "order" button by a stick with the order and the collapse
-    // buttons
+    // replace the "order" button by a stick containing the order and the
+    // collapse buttons
     const orderElem = document.getElementById('toggle-order');
 
-    let stickElem = document.createElement('div');
+    const stickElem = document.createElement('div');
     stickElem.classList.add('stick');
 
     orderElem.parentNode.insertBefore(stickElem, orderElem);
@@ -59,6 +63,6 @@
     stickElem.appendChild(toggleElem);
 
     // synchronizes the collapse button with dynamic vars passed via the
-    // backend.
+    // backend (async mode).
     syncWithContext();
 }());