Mobile Responsive Issuue

I’ve used “admin-custom-login” its really awesome & i really appreciate the work but i think its having issue when used on mobile.
Everything is fine on desktop but when i tried to login from my mobile everything is messed up.
Its not auto responsive.
Kindly guide me so i can fix this issue.
Thanks

https://ww.wp.xz.cn/plugins/admin-custom-login/