[Plugin: Fast Secure Contact Form] Email field not styled like other fields

I can’t remember which other site I used this on and had the same problem (I can find it if you need), but I’ve now used it on 2 sites where the Email field does not adopt the same CSS styling as the other fields. It’s strange, but something’s not right. Example here: https://petstopvet.fiddlersites.com/contact/

Am I doing something wrong? Or does the plugin have something set differently for email.

https://www.ads-software.com/extend/plugins/si-contact-form/