Improve mobile detection

Author: spinn

src/mixins/IsMobile.js

@@ -4,11 +4,17 @@
   https://www.ditdot.hr/en
 */
 
-// Simple mobile device/tablet detection
-const isIos = navigator.userAgent.match(/iphone|ipad|ipod/i) || (navigator.userAgent.indexOf("Mac") !== -1 && "ontouchend" in document)
-const isMobile = !!(typeof navigator !== 'undefined' && (isIos || navigator.userAgent.match(/android/i)))
+let
+  isIos = false,
+  isMobile = false
 
-// Mixin that adds an `isMobile` data variable
+if (typeof navigator !== 'undefined' && typeof document !== 'undefined') {
+  // Simple mobile device/tablet detection
+  isIos = navigator.userAgent.match(/iphone|ipad|ipod/i) || (navigator.userAgent.indexOf('Mac') !== -1 && 'ontouchend' in document)
+  isMobile = isIos || navigator.userAgent.match(/android/i)
+}
+
+// Mixin that adds `isMobile` and `isIos` data variables
 export const IsMobile = {
   data() {
     return {