"Submit" button in all forms is barely visible and too small on white background

Hi,
I have no knowledge of html or php. Can you please help me with fixing the Submit button so users can see it clearly. Right now, it’s very pale gray and text is floating off the bottom because the button appears too small. Is there a fix or a script you can send me that will fix the problem?

take a look at https://www.psychpiper.com/login/

Thanks!

https://www.ads-software.com/plugins/front-end-only-users/