Mobile margin top and bottom

I need reduce a margin top of logo
and a margin bottom of menu button
to reduce a height of header in a mobile device.

Hello, try to use the following CSS code.

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

@media (max-width: 1024px) {
    #masthead {
        padding: 0 0 10px;

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

Kind Regards, Roman.