diff --git a/src/js/plugins/zoom.js b/src/js/plugins/zoom.js
index 2b9d49c..398a220 100644
--- a/src/js/plugins/zoom.js
+++ b/src/js/plugins/zoom.js
@@ -128,12 +128,12 @@ export default class Zoom {
     const scale = divCSS.width.includes('%') ?
       100 / DOM.parseSize(divCSS.width) :
       window.innerWidth / DOM.parseSize(divCSS.width);
-    if (scale == 1) {
+    if (scale === 1) {
       // If the scale is 100% means it is mobile
       const wsW = this.ws_.el.clientWidth;
       elem.el.style.width = `${(wsW - marginW) * 2}px`;
       elem.el.style.height = `${(wsW - marginH) * 1.5}px`;
-      elem.el.style.minHeight = scale == 1? 'auto' : '';
+      elem.el.style.minHeight = scale === 1 ? 'auto' : '';
       // Because of flexbox, wrap height is required
       wrap.style.height = `${(wsW - marginH) * 1.5 / 2}px`;
     } else {
diff --git a/src/js/utils/dom.js b/src/js/utils/dom.js
index 643ee00..5912b6a 100644
--- a/src/js/utils/dom.js
+++ b/src/js/utils/dom.js
@@ -213,7 +213,7 @@ export default class DOM {
   static after(elem, target) {
     const parent = target.parentNode;
 
-    if (parent.lastChild == target) {
+    if (parent.lastChild === target) {
       parent.appendChild(elem);
     } else {
       parent.insertBefore(elem, target.nextSibling);