diff --git a/style.css b/style.css
index 4c15eb2..4b40943 100644
--- a/style.css
+++ b/style.css
@@ -25,6 +25,7 @@ header {
   border: 1px solid #ddd;
   background: white;
   position: relative;
+  aspect-ratio: 1 / 1;
 }
 
 .thumb img {