Is it possible to hide header on desktop/tablet, but show on mobile?

Basically the designer wanted to have a navigation layout that wasn't a default layout option provided in 7.1.

I am hoping to disable the navigation on desktop + tablet, but show the default burger menu on mobile. 

I have tried several versions of media queries to hide the header, but they keep seeming to be ignored. I can only get the header to hide, sitewide, not specific to browser width. 

I'm posting the media queries in the Custom CSS editor. 

Any ideas?

P: spinach2022

/* ------------ MOBILE SPECIFIC QUERIES --------------------- */

@media screen only and (max-width: 640px) {

}

/* ------------ TABLET SPECIFIC QUERIES --------------------- */

@media screen only and (min-width: 641px) and (max-width:950px) {
  
/* Hide Navigation */

 #header {
       display: none !important;
    }
}

/* ------------ DESKTOP SPECIFIC QUERIES --------------------- */

@media screen only and (min-width: 951px) {
  
/* Hide Navigation */

  #header {
       display: none !important;
    }

}
 

URL is not posting for some reason, test URL; https://chipmunk-ellipse-66gh.squarespace.com/

Try this instead:

@media only screen and (min-width: 641px) { 
  .header {
     display: none;
  }
}

.header instead of #header.

Position of only in the media query wasn't correct.