Fix sidenav issues

Author: juujisai

src/js/navigation/sidenav.js

@@ -211,15 +211,21 @@ class Sidenav {
     const { x } = this._element.getBoundingClientRect();
 
     if (
-      (this.options.sidenavRight && !isRTL) ||
-      (!this.options.sidenavRight && isRTL)
+      (this.options.sidenavRight && !isRTL()) ||
+      (!this.options.sidenavRight && isRTL())
     ) {
       let scrollBarWidth = 0;
       // check if there is scrollbar and account for it width if there is one
-      if (this.container.scrollHeight >= this.container.clientHeight) {
+      if (this.container.scrollHeight > this.container.clientHeight) {
         scrollBarWidth =
           this.container.offsetWidth - this.container.clientWidth;
       }
+
+      if (this.container.tagName === "BODY") {
+        const documentWidth = document.documentElement.clientWidth;
+        scrollBarWidth = Math.abs(window.innerWidth - documentWidth);
+      }
+
       return Math.abs(x + scrollBarWidth - containerEnd) > 10;
     }