expand calltree node only when click icon

index.html

@@ -175,6 +175,10 @@
         cursor: pointer;
         display: inline-block;
       }
+      .call_el .expand_icon {
+        padding-left: 5px;
+        padding-right: 2px;
+      }
       .call_header {
         white-space: nowrap;
       }