Mobile header & toggle menu + font size

Hi,

1) i was using the following code to use the fixed sticky header for mobile version and it works very well. But unfortunately the header covers the breadcrumb or everything underneath (like slider) on mobile. do you know how i can fix it?

@media only screen and (max-width: 768px){
#header.sticky_header {
position: fixed;
}
}

2) You have send me before the following code for “toggle” the mobile menu instead of default function (accordion). But unfortunately it does not working. Even not after deleting the browser cache. do you have a better solution?

jQuery('#mobile_menu').stop(true,true).fadeToggle(400,"easeOutCubic");

3) Do you have an easy way to change the font size (or font family) of the mobile menu?

Thanks for your feedback!
Best regards