The lang attribute does not default to English. It defaults to an unknown, which is an accessibility issue.
@@ -1,5 +1,5 @@
<!doctype html>
-<html>
+<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">