diff --git a/assets/app.css b/assets/app.css
index 6bfbee7..6b89b2e 100644
--- a/assets/app.css
+++ b/assets/app.css
@@ -3,7 +3,7 @@
  * A simple, clean, flexible Hugo theme
  * https://github.com/nanxiaobei/hugo-paper
  * Designed by 南小北 (https://lee.so/)
- * Updated in 2021.8.20
+ * Updated in 2021.8.24
  */
 
 /* Theme
@@ -432,7 +432,7 @@ img {
 .post-content h4,
 .post-content h5,
 .post-content h6 {
-  margin-block: 3rem;
+  margin-block: 2rem;
 }
 
 .post-content h1 {
@@ -461,6 +461,10 @@ img {
   font-size: 1.5rem;
 }
 
+.post-content img {
+  margin-inline: auto;
+}
+
 .post-content a {
   padding-bottom: 1px;
   border-bottom: 1.5px solid var(--pro);