Use fixed position instead of sticky for sidenav and top bar so it works in IE

styles/components/_global_layout.scss

@@ -25,9 +25,12 @@ body {
     margin: $gap;
     flex-grow: 1;
     -ms-flex-negative: 1;
+    top: 68px;
+    position: relative;
 
     @include media($medium-screen) {
       margin: $gap * 2;
+      top: 68px;
     }
   }
 }