fixed z-index for hover over icon in mobile view

Signed-off-by: Kai Wagner <kai.wagner@percona.com>

Author: ImTheKai

app/assets/stylesheets/components/topics.css

@@ -525,6 +525,7 @@ a.topic-icon {
 
   .topic-title-mobile {
     display: flex;
+    z-index: auto;
   }
 
   .topic-row-footer {
@@ -545,6 +546,9 @@ a.topic-icon {
     font-size: var(--font-size-2xs);
   }
 
+  .topic-icon-hover {
+    z-index: 200;
+  }
 }
 
 .topic-link {