i got the same problem. http://nefertariappingedam.nl/ when watched on mobile device the menu goes over the logo.
found a solution for the problem. Go to >theme > theme options > layout > and then place this in custom css.
@media screen and (max-width: 480px) {
#header {
position: relative;
padding-bottom: 30px;
}
#access {
background: none;
}
#access,
#access .nav-show,
#access a.nav-show:hover {
bottom: 0;
}
#access .nav-show,
#access a.nav-show:hover {
top: initial;
left: 44%;
}
#access:target .menu {
margin-top: 0;
}
}
awesome, looks a little different but the overlapping is not longer an issue.. thanks!