fix: code margin on mobile

Author: yyx990803

lib/default-theme/styles/mobile.styl

@@ -29,8 +29,9 @@ $mobileSidebarWidth = $sidebarWidth * 0.82
 @media (max-width: $MQMobileNarrow)
   h1
     font-size 1.9rem
-  pre, pre[class*="language-"]
-    margin 0.85rem -1.5rem
-    border-radius 0
   .content:not(.custom)
     padding 1.5rem
+  .content
+    pre, pre[class*="language-"]
+      margin 0.85rem -1.5rem
+      border-radius 0