Fix list number clipping and spacing in blog post layout

Increase padding-left to 2.5rem so ordered list numbers are fully
visible, and add vertical spacing between list items.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: congwang-mk

_layouts/post.html

@@ -55,7 +55,12 @@
 .blog-content ul,
 .blog-content ol {
     margin-bottom: 1rem;
-    padding-left: 1.5rem;
+    padding-left: 2.5rem;
+}
+
+.blog-content ol li,
+.blog-content ul li {
+    margin-bottom: 0.5rem;
 }
 
 .blog-content a {