nav {
    display: grid;
    grid-template-rows: 4rem 1fr;
    position: absolute;
    top: 0px;
    left: 0px;
    width: 100%;
}

button.nav-button {
    margin-left: 15px;
    display: grid;
    place-items: center;
    border: unset;
    padding: unset;
    width: 4rem;
    height: 4rem;
    background-color: #aaa;
    border: solid 1px black;
    border-top: unset;
    border-radius: 0px 0px 5px 5px;
    cursor: pointer;
}
    button.nav-button .material-icons {
        font-size: 3rem;
    }

nav ul {
    display: grid;
    grid-auto-rows: 3rem;
    place-items: center;
    width: 100%;
    list-style-type: none;
    background-color: #aaa;
    border: solid 1px black;
    margin: 0px;
    padding: 0px;
    overflow-y: auto;
}

nav li {
    width: 100%;
    height: 100%;
    border-bottom: solid 1px black;
}

nav a {
    display: grid;
    place-items: center;
    width: 100%;
    height: 100%;
    text-decoration: none;
    text-align: center;
    color: black;
    font-size: 1.3rem;
}

nav[aria-expanded="true"] {
    height: 100%;
}

nav[aria-expanded="false"] button.nav-button {
    box-shadow: 3px 3px 5px rgba(0, 0, 0, 0.3);
}

nav[aria-expanded="true"] button.nav-button {
    grid-template-columns: 15px 4rem 1fr;
    width: 100%;
    margin-left: unset;
    border-bottom: unset;
    border-radius: unset;
}

nav[aria-expanded="true"] button.nav-button span.material-icons {
    grid-column: 2 / 3;
}

nav[aria-expanded="false"] ul {
    display: none;
}

@media screen and (min-width: 500px) {
    nav {
        width: 350px;
    }
    
    nav[aria-expanded="true"] {
        box-shadow: 3px 3px 5px rgba(0, 0, 0, 0.3);
    }
}