How to fix header on mobile devices [closed]

I have site, and when I open it from my phone I get this header
header
How to fix it?(on pc it works correctly )
It will be easier if I give you link on site, I can’t write code from phone. Sorry

my site

.header {
    background: #19191986;
    backdrop-filter: blur(3px);
    height: 60px;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    transition: all 0.3s ease;
    z-index: 99999999;
}

Please better check site, not code