feat: 调整RecommendPostsList组件样式

src/static/scss/rounded.scss

@@ -11,6 +11,14 @@
   border-radius: 12px;
 }
 
+.rounded-16 {
+  border-radius: 16px;
+}
+
+.rounded-20 {
+  border-radius: 20px;
+}
+
 .rounded-full {
   border-radius: 50%;
 }