[SDK-1413] Re-added scrollbars and fixed password strength popup clip…

… issue (auth0#1839)

* Moved header into wrapper, fixed styles, re-added scrollbars

* Automatically calculated margin for inner content to clear header

* Added render tests for Chrome box

css/index.styl

@@ -157,8 +157,6 @@ loadingSize = 30px
 
 
   // Lock header content
-
-
   .auth0-lock-header
     text-align center
     padding 11px
@@ -172,26 +170,22 @@ loadingSize = 30px
     display: flex
     flex-direction: column
     justify-content: center
-    flex-shrink: 0;
-    flex-grow: 0;
-    flex-basis: auto;
+    flex-shrink: 0
+    flex-grow: 0
+    flex-basis: auto
+    position: absolute
+    width: 100%
+    z-index: 1000
 
   .auth0-lock-content-wrapper
     flex-grow: 1
     flex-shrink: 1
     flex-basis: auto
     -webkit-overflow-scrolling touch
     overflow-x: auto
-    overflow-y: scroll
-    scrollbar-width: none; /* Firefox */
-    -ms-overflow-style: none;  /* Internet Explorer 10+ */
-
-    &::-webkit-scrollbar
-      width: 0
-      height: 0
 
-    @media screen and (min-width: 481px)
-      overflow-x: inherit;
+  .auth0-lock-content-body-wrapper
+    padding-top 10px
 
   .auth0-lock-close-button, .auth0-lock-back-button
     -webkit-box-sizing content-box !important