Full screen hamburger menu

Hey, 

I have a navigation menu for mobile. I want this hamburger menu to go full-screen, instead of opening up above. Right now, when it's clicked, a small navigation menu is opening up from above.

I'm adding two images, first one is what it looks like right now, and the second one is how I want it to look like. Is this something I can do with just custom CSS? Would anyone know how I can achieve this? Here is my website: https://www.esinozcan.com/

Try adding to Design > Custom CSS

div#mobileNav.menu-open {
    position: fixed;
    height: 100vh !important;
    left: 0;
    width: 100%;
    background-color: white;
    z-index: 999;
    display: flex;
    align-items: center;
    justify-content: center;
}

.menu-open div#mobileNavWrapper {
    background: white;
}

Thank you!