add styling to code blocks with line nums

Kept styling the same for code blocks without line nums, added similar
styling for code blocks with line nums

css/main.css

@@ -586,18 +586,42 @@ table tr td :last-child {
 }
 
 /* --- Code blocks --- */
-
 pre {
   font-size: 16px;
   line-height: 1.5em;
+}
+pre code {
+  white-space: pre;
+}
+pre.highlight, .highlight > pre, td.code pre {
   background: #FAFAFA;
-  background-image: linear-gradient(#FAFAFA 50%, #FDFDFD 50%);
-  background-position: 0px 10px;
+  background-image: linear-gradient(#F9F9F9 50%, #FDFDFD 50%);
   background-repeat: repeat;
   background-size: 3em 3em;
+  background-position: 0px 10px;
   border-left: 7px solid #444;
 }
-
-pre code {
-  white-space: pre;
+.highlight > pre {
+  padding: 0;
+  margin: 0;
+}
+td.code pre {
+  border: none;
+  border-left: 2px solid #444;
+  border-radius: 0;
+  background: transparent!;
+}
+td.gutter pre {
+  border: none;
+}
+td.gutter {
+  padding-top: 3px;
+}
+code table {
+  border-collapse: collapse;
+  border: none;
+}
+code table td, code table th, code table tbody, code table tr {
+  padding: 0;
+  border: none;
 }