Hello: I am working on the below form and was wondering if there is a simple way to have the form fields fill more of the background area.
Currently I have the background set just in the content editor but I know how to do this in the CSS as well so I am open to all suggestions of how to make this work!
The first field in your screenshot is for class names not css definitions, so you might actually be breaking something by having CSS in that first field.
To answer your question aside from that, you would put
.hs-form {max-width:100%;width:850px;}
in your styles.css or whatever stylesheet your landing page is using.