Fix card flip flickering.

Closes #451.

resources/report/html/loot-plugin-card.html

@@ -66,11 +66,10 @@ loot-clear-metadata
         }
         #front {
             display: block;
-            transform: translateZ(1px);
             backface-visibility: hidden;
         }
         #editor {
-            transform: rotateY(180deg) translateZ(-1px);
+            transform: rotateY(180deg);
             display:none;
             backface-visibility: hidden;
         }

resources/report/html/loot-plugin-editor.html

@@ -91,11 +91,8 @@ loot-editor-close
         }
 
         /* Misc Styling. */
-        :host {
-            background: #CFD4E9;
-        }
         core-toolbar.medium-tall {
-            background: transparent;
+            background: #CFD4E9;
             height: 104px;
         }
         core-toolbar > div {
@@ -108,9 +105,10 @@ loot-editor-close
             vertical-align: inherit !important;
         }
         core-selector > * {
-            border-bottom: 4px solid #CFD4E9;
+            border: 4px solid #CFD4E9;
+            border-top: none;
             background: white;
-            margin: 0 4px 4px 4px;
+            margin-bottom: 4px;
         }
         #main {
             padding: 16px;