Hi I'm looking to do the same, I want to hide the background on mobile only for 1 page. I have the block ID on chrome, and I did test out other Id's with this code and it works fine, just for some reason not my background?
anyone figure anything out?
this is what I used - Ive used 640px across all mobile edits for size. tried the 768 px to see if it made a difference and it didnt.
it seems to only shift the background image slightly
@media only screen and (max-width: 640px) {
#block-yui_3_17_2_1_1590078744292_9450 {
display: none;
}
}