Hi there,
Remove this CSS from Additional CSS field in the customizer:
#site-navigation .inside-navigation {
border-bottom: 1px solid rgba(0,0,0,0.2);
}
.header-wrap #site-navigation .inside-navigation {
border-color: rgba(255,255,255,0.3);
}
.site-info {
border-top: 1px solid rgba(0,0,0,0.2);
}
Let me know if this helps 🙂