Split layout background color on mobile

Hello all,

here is my CSS for changing the background color:

//HOME
//background color

section[data-section-id="65a53c30eb5380339bb8aa0d"] .section-background {
    background-color: #fff!important;
}

@media only screen and (max-width: 641px){
section[data-section-id="65a53c30eb5380339bb8aa0d"] .section-background {
    background-color: #fff!important;

  }}

There is unfortunately this strip at the bottom of the mobile version that has not been affected by the change:

How can I change it also to white?

Thank you.

Try this CSS code, if it doesn't work, please share your site url

body {
	background-color: white !important;
}