fix(playground): add back underline on tree nodes, and query error underline

Author: amaanq

docs/src/assets/css/playground.css

@@ -206,6 +206,11 @@ input[type="checkbox"]:focus {
   background: rgba(36, 99, 180, 0.12) !important;
 }
 
+.query-error {
+  text-decoration: underline red dashed;
+  -webkit-text-decoration: underline red dashed;
+}
+
 /* Output Container Styles */
 #output-container {
   color: #080808;
@@ -230,6 +235,10 @@ input[type="checkbox"]:focus {
   text-decoration: none;
 }
 
+#output-container a:hover {
+  text-decoration: underline;
+}
+
 #output-container a.node-link.anonymous {
   color: #116329;
 }