feat(code-block): minor refine code-block style

static/css/admonition.css

@@ -17,8 +17,19 @@ div.admonition p a {
   color: inherit !important;
 }
 
-div.admonition pre {
-  margin: 0.4em 1em 0.4em 1em;
+div.admonition div.highlight {
+  margin-left: 1em;
+  margin-right: 1em;
+}
+
+div.admonition table.highlighttable {
+  padding-left: 1em;
+  padding-right: 1em;
+}
+
+div.admonition table.highlighttable div.highlight {
+  margin-left: 0;
+  margin-right: 0;
 }
 
 div.admonition p.admonition-title {

static/css/elegant.css

@@ -145,6 +145,15 @@ td.code {
 div.highlight {
   margin-bottom: 20px;
 }
+table.highlighttable {
+  border: none;
+}
+table.highlighttable td {
+  border: none;
+}
+table.highlighttable tbody > tr:nth-child(odd) > td {
+  background-color: transparent;
+}
 /* Tags */
 .list-of-tags {
   font-family: "Helvetica Neue", Helvetica, Arial, Sans-Serif;