some help styling contact forms please

I’m an absolute beginner struggling to figure out all these things as my web designer abandoned me. I’ve spent many hours reading the guide and experimenting but there’s a few things I can’t work out so I’d love some help please.

Q1. What is the correct way to set the button colour please?
I would like to style the button to match the rest of my website. With my theme came a few Contact Form 7 templates. One has styling for button but it only partially works…

<p>[submit class:btn-color-primary class:btn-full-width class:btn-shape-semi-round “Send”]</p>

It makes corners semi-round (I’ve also tried round & that works too) but it doesn’t make button full width and more importantly it doesn’t change the colour of the button. I’ve also tried class:btn-color-#00a5bf but the button remains a horrible light grey.

Q2. “Locating response message box anywhere” is not working for me. Following instructions on https://contactform7.com/locating-response-message-box-anywhere/ I put “ [response] “ in the Form Tab (I tried at top, middle and between Message and submit tags) but the response still appears as banner across bottom of screen, not like the demo. Is there a step missing??

Q3. Is there a way to add CSS (or any styling) to the Mail tab? In the message body I have put some text. Is there a way to make some of this text appear bold when it comes in the email?

Q4. Any way to add icons in Form? I have set up contact form for people to place reviews and added radio buttons with labels “1 star” “2 stars” etc. Any way I could replace these words with star icons? Or should I be doing this a different way?

Thanks in advance!