fix height of title panel in image preview

css/base.css

@@ -1579,8 +1579,10 @@ img.channel {
   justify-content: space-between;
   background-color: #eceff1;
   box-shadow: 0 1px 2px silver; /* Faint shadow under the panel */
-  line-height: 2.5rem;
-  height: 4.6rem;
+  line-height: 2rem;
+  flex-shrink: 0;
+  flex-grow: 0;
+  height: 4rem;
   padding: 1rem 0.75rem 0 0.75rem;
   z-index: 3;
 }
@@ -1610,6 +1612,8 @@ img.channel {
   line-height: 1.5rem;
   background-color: #eceff1;
   box-shadow: 0px -2px 3px -1px rgba(0,0,0,0.1); /* Faint shadow above panel */
+  flex-grow: 0;
+  flex-shrink: 0;
   z-index: 1;
 }