Cover layout misaligned in Firefox iOS at phone size

There's an alignment issue on the cover page in Firefox iOS at phone size (pictured below). It's due to the use of vh units (viewport heights) but works as needed on all other browsers so I'm hesitant to rewrite all the styles. As of this posting, I haven't been able to find a way to target Firefox iOS with CSS queries, or found a way to test within that particular browser short of pushing changes to the site and waiting to see what, if any, effect they have.

@supports (-moz-appearance:none) {
    ...
}
@-moz-document url-prefix() {
    ...
}
@supports (-moz-text-size-adjust:none) {
    ...
}
@supports (-moz-user-select:none) {
    ...
}

Firefox iOS

firsfox-ios

Chrome iOS

chrome-ios

Safari iOS

safari-ios

thegetty / artists-things

Cover layout misaligned in Firefox iOS at phone size #44