fix design issues

Author: GoodDayForSurf

packages/devextreme-cli/src/templates/react/application/src/dx-styles.scss

@@ -25,6 +25,7 @@ body {
     display: flex;
     height: 100%;
     width: 100%;
+    min-width: 320px;
   }
 
   .content {

packages/devextreme-cli/src/templates/vue-v3/application/src/App.vue

@@ -93,5 +93,6 @@ body {
   display: flex;
   height: 100%;
   width: 100%;
+  min-width: 320px;
 }
 </style>

packages/devextreme-cli/src/templates/vue-v3/application/src/dx-styles.scss

@@ -15,10 +15,10 @@ $side-panel-min-width: 60px;
       margin: 0;
       line-height: 40px;
     }
+  }
 
-    .screen-x-small & {
-      padding: 20px;
-    }
+  .screen-x-small .content {
+    padding: 20px;
   }
 
   .container {

packages/devextreme-schematics/src/add-layout/files/src/dx-styles.scss

@@ -24,6 +24,7 @@ html, body {
     display: flex;
     height: 100%;
     width: 100%;
+    min-width: 320px;
   }
 
   .content {
@@ -36,10 +37,10 @@ html, body {
       margin: 0;
       line-height: 40px;
     }
+  }
 
-    .screen-x-small & {
-      padding: 20px;
-    }
+  .screen-x-small .content {
+    padding: 20px;
   }
 
   .container {