Add share dialog for collections (#37986)

app/javascript/styles/mastodon/components.scss

@@ -6408,15 +6408,15 @@ a.status-card {
     line-height: 20px;
     color: var(--color-text-secondary);
 
-    h1 {
+    :where(h1) {
       font-size: 16px;
       line-height: 24px;
       color: var(--color-text-primary);
       font-weight: 500;
+    }
 
-      &:not(:only-child) {
-        margin-bottom: 8px;
-      }
+    :where(h1:not(:only-child)) {
+      margin-bottom: 8px;
     }
 
     strong {