How to make a horizontal form?

I like what you guys have but how can I make a horizontal for with these sections.

Full Name, Phone, Email. 

All in one horizontal form. 

I like this one: https://www.jotform.com/theme-store/theme/horizontal-flat

But how can I add a field to it. 

Please write back as soon as you can, thanks!

The theme you linked was specifically designed for two fields only, the name and email. Nevertheless, I made a demo form with an added Phone Number field per your requirement. You can check out the demo here: https://form.jotform.com/70258743531961 

To clone the form to your account, please see this guide: How to Clone an Existing Form from a URL
Regards.

Thank you!

Is there a way to make it full width?

The Submit keeps getting hidden.

You can insert this CSS code:

.form-all {
   width: 100% !important;
}

Here's a guide on How-to-Inject-Custom-CSS-Codes. Here's the result:

If this does not help, please more details about the issue. Thank you.