feat(ui): the tablet width is now 768px

Author: did

app/frontend/editor/mixins/global.js

@@ -115,7 +115,7 @@ Vue.mixin({
     deviceWidthMap() {
       return {
         mobile: 375,
-        tablet: 1024,
+        tablet: 768,
       }
     },
   },

app/frontend/editor/views/page-preview.vue

@@ -148,7 +148,7 @@ export default {
 }
 
 .tablet {
-  width: 1024px;
+  width: 768px;
   height: 100%;
   /* max-height: 1366px;   */
 }