Fix opacity of relationship tags (#10411)

app/javascript/styles/mastodon/components.scss

@@ -3064,15 +3064,19 @@ a.status-card.compact:hover {
 .relationship-tag {
   color: $primary-text-color;
   margin-bottom: 4px;
-  opacity: 0.7;
   display: block;
   vertical-align: top;
-  background-color: rgba($base-overlay-background, 0.4);
+  background-color: $base-overlay-background;
   text-transform: uppercase;
   font-size: 11px;
   font-weight: 500;
   padding: 4px;
   border-radius: 4px;
+  opacity: 0.7;
+
+  &:hover {
+    opacity: 1;
+  }
 }
 
 .setting-toggle {