change background color of one mobile page

I have a mobile page that needs a dark background but on mobile only. the desktop version can stay the same.

I have a module block on that page with a dark BG and there is a gap between it and the header and the footer and I cant fill it with padding or border settings in Composer, so I need to change the background of the entire page.

I tried this:

@media(min-width:767px){
.page-2807{
background-color: #141414;
}}

but it doesnt work.

nevermind

I fixed it

@media(max-width:767px){
.page-id-2807 .td-main-page-wrap {
background-color: #141414;
}}