Fix code padding, bkg color during dark mode

Author: john-b-yang

static/css/layout.css

@@ -365,7 +365,7 @@ nav {
 
 /* Code blocks */
 pre {
-    background-color: var(--bg);
+    background-color: var(--bg) !important;
     border: 1px solid var(--border);
     border-radius: 0.5em;
     padding: 1rem;
@@ -374,6 +374,16 @@ pre {
     color: var(--fg);
 }
 
+pre.prettyprint {
+    background-color: var(--bg) !important;
+    padding: 1rem !important
+}
+
+:root[data-theme="dark"] pre,
+:root[data-theme="dark"] pre.prettyprint {
+    background-color: var(--fg) !important;
+}
+
 pre p {
     margin: 0;
 }