diff --git a/styles.css b/styles.css
index 86436c5..d85b5dc 100644
--- a/styles.css
+++ b/styles.css
@@ -18,6 +18,7 @@
     padding: 0;
     border: 0;
     text-align: center;
+    box-sizing: border-box;
 }
 
 a, a:visited, a:active {