diff --git a/less/topic.less b/less/topic.less
index c2ce83a..58a7c9b 100644
--- a/less/topic.less
+++ b/less/topic.less
@@ -220,6 +220,10 @@
 				}
 			}
 
+			iframe, .img-responsive {
+				max-width: 400px;
+			}
+
 			.toggle {
 				padding: 0px 5px;
 				border: 1px solid #e0e0e0;