Reduce heading sizes

Author: thomasspriggs

src/cbmc_style.css

@@ -9,3 +9,18 @@ code {
 	padding-left: 4px;
 	padding-right: 4px;
 }
+
+h1 {
+	font-size: 1.3em;
+	margin: 0.9em 0;
+}
+
+h2 {
+	font-size: 1.2em;
+	margin: 0.6em 0;
+}
+
+h3 {
+	font-size: 1.1em;
+	margin: 0.3em 0;
+}