How to change the opacity of 'Submit' button in a form?

We are currently using Webflow’s Contact Form component, and would like to set the default opacity of the ‘Submit’ button to about 40%.

We would like the opacity to change to 100% once the user had filled out all the required fields.

Would anyone here know a solution/workaround to this please? If there is no way to do so using Wbeflow’s own Contact Form component, it would be equally and much appreciated for a tutorial/some instructions on how to send the filled-out information to somewhere (e.g. to an inbox etc.). We can re-created the look of the form, but pretty much pulling a blank on how to do the next bits.

Here’s our read-only link

Thanks! :slight_smile: