CSS Scroll bar not showing up on Mobile

Site URL: https://www.nyckwalsh.com

Hi there, so I added a custom scroll bar. It shows up on desktop, but not on mobile. Looking for support to get it on mobile.

Thank you!

Mobile, with no rainbow scroll:

Desktop with rainbow scroll:

Where did you get this code? Some code like this won't work properly on all devices/browser

::-webkit-scrollbar {
    width: 1rem
}

::-webkit-scrollbar-track {
    background: linear-gradient(to bottom,red,orange,#ff0,green,blue,purple) !important
}

::-webkit-scrollbar-thumb {
    background-color: rgba(255,255,255,.5);
    border-radius: 1rem;
    border: 3px solid #fff
}