diff --git a/assets/styles/styles.css b/assets/styles/styles.css
index 53fee4d1..a372369b 100644
--- a/assets/styles/styles.css
+++ b/assets/styles/styles.css
@@ -60,6 +60,7 @@ button {
 /* default iframe borders are just ugly */
 iframe {
   border: 0;
+  max-width: 100%;
 }
 
 * {