Hi there!
Sorry for the delay!
If I get it right, you want the header element to appear as it looks while scrolling down.
https://prnt.sc/12hpcj7
https://prnt.sc/12hpd15
So I am sharing some code with you to change the header appearance specifically for the form view. Please use the following code in your custom CSS:
body.com-rsform #sp-main-body {
padding-top: 150px !important;
}
body.com-rsform:not(.solid-header) #sp-header .sp-megamenu-parent > li > a {
color: #252525;
}
body.com-rsform:not(.solid-header) #sp-header .logo-image {
display:block!important;
}
body.com-rsform #sp-header .logo .logo-image.white-logo {
display: none!important;
}
Hope this will closure to your wish!
Let me know the result.
Best Regards