css: Make horizontal rules more visible (#178)

static/css/hugo-academic.css

@@ -151,6 +151,13 @@ pre {
   overflow: auto;
 }
 
+hr {
+  border: 0;
+  height: 1px;
+  background: #333;
+  background-image: linear-gradient(to right, #ccc, #333, #ccc);
+}
+
 /* Quotes */
 blockquote {
   padding: .5rem 1rem;