fix border style

media/css/sandstone/sandstone.less

@@ -195,7 +195,7 @@ li {
             .inline-block;
             margin: 0;
             a {
-                border-left: 1px solid @borderColor;
+                border-left: 1px dotted @borderColor;
                 padding: @baseLine / 3 @baseLine;
             }
             &:first-child a {