UX: fix spacing of composer preview on mobile

UX: fix spacing of composer preview on mobile

Followup to 723d7e3a

diff --git a/app/assets/stylesheets/mobile/compose.scss b/app/assets/stylesheets/mobile/compose.scss
index 76d2634..21e6c06 100644
--- a/app/assets/stylesheets/mobile/compose.scss
+++ b/app/assets/stylesheets/mobile/compose.scss
@@ -122,9 +122,13 @@
   }
 
   &.show-preview {
-    .submit-panel .save-or-cancel {
+    .submit-panel {
+      padding-top: 10px;
       z-index: z("fullscreen") + 1;
-      .cancel {
+      background-color: $secondary;
+      .cancel,
+      .mobile-file-upload,
+      .mobile-preview {
         display: none;
       }
     }
@@ -145,12 +149,6 @@
         margin-bottom: 40px;
       }
     }
-    .btn.hide-preview {
-      position: fixed;
-      right: 5px;
-      bottom: 5px;
-      z-index: z("fullscreen") + 1;
-    }
   }
 
   &.hide-preview {

GitHub sha: 1100b3d1