diff --git a/src/display/font_loader.js b/src/display/font_loader.js
index ba9421aa8..b44f77f33 100644
--- a/src/display/font_loader.js
+++ b/src/display/font_loader.js
@@ -341,12 +341,11 @@ if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) {
       names.push(loadTestFontId);
 
       const div = document.createElement("div");
-      div.setAttribute(
-        "style",
-        "visibility: hidden;" +
-          "width: 10px; height: 10px;" +
-          "position: absolute; top: 0px; left: 0px;"
-      );
+      div.style.visibility = "hidden";
+      div.style.width = div.style.height = "10px";
+      div.style.position = "absolute";
+      div.style.top = div.style.left = "0px";
+
       for (i = 0, ii = names.length; i < ii; ++i) {
         const span = document.createElement("span");
         span.textContent = "Hi";
diff --git a/web/debugger.js b/web/debugger.js
index 3208f7bd4..12ebce779 100644
--- a/web/debugger.js
+++ b/web/debugger.js
@@ -67,7 +67,6 @@ var FontInspector = (function FontInspectorClosure() {
     manager: null,
     init: function init(pdfjsLib) {
       var panel = this.panel;
-      panel.setAttribute("style", "padding: 5px;");
       var tmp = document.createElement("button");
       tmp.addEventListener("click", resetSelection);
       tmp.textContent = "Refresh";
@@ -178,7 +177,6 @@ var StepperManager = (function StepperManagerClosure() {
     manager: null,
     init: function init(pdfjsLib) {
       var self = this;
-      this.panel.setAttribute("style", "padding: 5px;");
       stepperControls = document.createElement("div");
       stepperChooser = document.createElement("select");
       stepperChooser.addEventListener("change", function(event) {
@@ -468,9 +466,7 @@ var Stats = (function Stats() {
     name: "Stats",
     panel: null,
     manager: null,
-    init(pdfjsLib) {
-      this.panel.setAttribute("style", "padding: 5px;");
-    },
+    init(pdfjsLib) {},
     enabled: false,
     active: false,
     // Stats specific functions.
diff --git a/web/pdf_outline_viewer.js b/web/pdf_outline_viewer.js
index bf2f058c5..a50cb977e 100644
--- a/web/pdf_outline_viewer.js
+++ b/web/pdf_outline_viewer.js
@@ -94,16 +94,11 @@ class PDFOutlineViewer {
    * @private
    */
   _setStyles(element, { bold, italic }) {
-    let styleStr = "";
     if (bold) {
-      styleStr += "font-weight: bold;";
+      element.style.fontWeight = "bold";
     }
     if (italic) {
-      styleStr += "font-style: italic;";
-    }
-
-    if (styleStr) {
-      element.setAttribute("style", styleStr);
+      element.style.fontStyle = "italic";
     }
   }
 
diff --git a/web/secondary_toolbar.js b/web/secondary_toolbar.js
index 24048416a..32bc4601f 100644
--- a/web/secondary_toolbar.js
+++ b/web/secondary_toolbar.js
@@ -340,10 +340,8 @@ class SecondaryToolbar {
     if (this.containerHeight === this.previousContainerHeight) {
       return;
     }
-    this.toolbarButtonContainer.setAttribute(
-      "style",
-      "max-height: " + (this.containerHeight - SCROLLBAR_PADDING) + "px;"
-    );
+    this.toolbarButtonContainer.style.maxHeight = `${this.containerHeight -
+      SCROLLBAR_PADDING}px`;
 
     this.previousContainerHeight = this.containerHeight;
   }
diff --git a/web/ui_utils.js b/web/ui_utils.js
index db12afa12..648b65302 100644
--- a/web/ui_utils.js
+++ b/web/ui_utils.js
@@ -890,10 +890,7 @@ class ProgressBar {
     const container = viewer.parentNode;
     const scrollbarWidth = container.offsetWidth - viewer.offsetWidth;
     if (scrollbarWidth > 0) {
-      this.bar.setAttribute(
-        "style",
-        "width: calc(100% - " + scrollbarWidth + "px);"
-      );
+      this.bar.style.width = `calc(100% - ${scrollbarWidth}px)`;
     }
   }
 
diff --git a/web/viewer.css b/web/viewer.css
index 6ff04aecd..871fdce15 100644
--- a/web/viewer.css
+++ b/web/viewer.css
@@ -1479,6 +1479,9 @@ html[dir='rtl'] #documentPropertiesOverlay .row > * {
   right: 0;
   top: 27px;
 }
+#PDFBug .panels > div {
+  padding: 5px;
+}
 #PDFBug button.active {
   font-weight: bold;
 }