三角

@@ -123,7 +123,19 @@
 
     .sub-level {
         width: 100%;
-        background-color: #f8f8f8;
+        background-color: #f6f6f6;
+
+        &:before {
+            content: "";
+            width: 0;
+            height: 0;
+            border-top: 20px solid transparent;
+            border-bottom: 20px solid transparent;
+            border-right: 20px solid #efefef;
+            position: absolute;
+            margin-top: 32px;
+            margin-left: -16px;
+        }
 
         &.hide {
             display: none;