More specific CSS selection and style <pre>

More specific CSS selection r educes margin on other list items

Better distinguish <pre> content on blog

services/web/public/stylesheets/app/blog-posts.less

@@ -11,7 +11,7 @@
     list-style: none;
     margin: 0;
     padding: 0;
-    li {
+    .blog-post {
       margin: 0 0 @margin-lg 0;
     }
     .card-header {
@@ -38,4 +38,10 @@
       font-size: small;
     }
   }
+
+  pre {
+    border: 1px solid @ol-blue-gray-2;
+    border-radius: @border-radius-base;
+    padding: @padding-sm;
+  }
 }