Try this local.css

diff --git a/underlay/local.css b/underlay/local.css
new file mode 100644 (file)
index 0000000..e0fad4d
--- /dev/null
+++ b/underlay/local.css
@@ -0,0 +1,3 @@
+pre {
+       border: gray 1px dashed;
+}