diff --git a/doc/doc.css b/doc/doc.css
new file mode 100644
index 0000000..9095707
--- /dev/null
+++ b/doc/doc.css
@@ -0,0 +1,15 @@
+div.section {
+  margin-left: 2em;
+  max-width: 40em;
+  border-left-style: solid;
+  border-width: 1px;
+  background-color: #FFF;
+}
+
+h2 {
+  background-color: #CCC;
+}
+
+h3 {
+  background-color: #CCC;
+}