I was able to force the desktop view to use the mobile "burger" menu for Squarespace templates like Hayden with this simple bit of CSS, but it doesn't work for Marquee.
#header #mainNavWrapper {
position: relative;
z-index: 1000;
width: 3600px;
}
Any clues as to what could trigger the mobile menu for Marquee? Several people including me have asked on Squarespace help boards but no one has an answer. Thanks