Fixed mobile menu

Please can you help with sticky menu in mobile mode??? Tried with custom css and change in style.css but position is still relative even if i change it to fixed. Thanks.
Website: https://www.kovo-central.cz/

Hello, try to use the following CSS code.

You can add CSS code in Customize → Additional CSS section.

#masthead {
    position: fixed !important;
}

Please feel free to ask any other questions that you might have.

Kind Regards, Roman.