Add <hr> theming; support disabling line numbers in code blocks

source/css/page.css

@@ -120,6 +120,33 @@ pre {
   background-color: var(--bg-code);
 }
 
+.nolinenum .lineno,
+.nolinenum .rouge-gutter {
+  visibility: hidden;
+  width: 0;
+  padding: 0;
+}
+
+/* breaks */
+hr {
+  color: var(--accent);
+  margin: 20px 2% 0 2%;
+  text-align: center;
+  border: none;
+  border-top: 1px solid;
+  overflow: visible;
+  counter-increment: item-counter;
+}
+
+hr:after {
+  content: counter(item-counter, upper-roman);
+  padding: 0 4px;
+  position: relative;
+  top: -13px;
+  font-size: 10px;
+  background: var(--bg);
+}
+
 /* header anchors */
 
 a[class="anchor"]::before {