nav ul {
    display: grid;
    padding: 0;
    margin: 0;
}

nav ul li {
    list-style-type: none;
    display: block;
    border-bottom: 1px solid;
    padding-left: 0;
    padding-right: 0;
    padding-top: 0;
}

nav ul li a {
    display: block;
    padding: 10px;
    text-decoration: none;
}

@media (max-width:767px) {
    header {
        padding-top: 50px;
    }

    nav {
        position: fixed;
        z-index: 1000;
        top: 0;
        left: 0;
        right: 0;
        background-color: rgba(0,0,0,0.9);
        color: rgba(255,255,255,0.8);
        height: 50px;
    }

    nav a.brand {
        position: absolute;
        top: 15px;
        text-decoration: none;
        font-weight: bold;
        color: rgba(255, 255, 255, 0.9);
        left: 15px;
    }

    nav a#nav-m,
    nav a.close {
        position: absolute;
        top: 15px;
        text-decoration: none;
        font-weight: bold;
        color: rgba(255, 255, 255, 0.9);
        right: 15px;
    }

    nav ul {
        grid-auto-flow: row;
    }

    nav #menu-wrap {
        top: 50px;
        position: absolute;
        background: rgba(0,0,0,0.9);
        width: 100%;
        left: -100%;
        list-style-type: none;
        margin: 0;
        padding: 0;
        transition: all 0.6s ease;
    }

    nav ul li {
        display: block;
        text-align: left;
        padding-left: 15px;
        border: none;
    }

    nav ul li a {
        color: rgba(255,255,255,0.8);
        padding: 1em 0;
    }

    nav ul.menu li a:hover {
        border-bottom: 0;
    }

    nav > .close,
    nav a#nav-m:target {
        display: none;
    }

    nav a:target ~ #menu-wrap,
    nav a:target ~ .close {
        display: inline-block;
    }

    nav a:target ~ .close {
        position: absolute;
        margin-left: -40px;
    }

    nav a:target ~ #menu-wrap {
        left: 0;
    }
}

@media (min-width:768px) {
    nav .brand {
        display: none;
    }

    nav ul {
        grid-auto-flow: column;
    }

    nav ul li {
        text-align: center;
        border-top: 1px solid;
        border-bottom: 1px solid;
    }

    nav ul li a {
        color: rgba(0, 0, 0, 0.8);
    }

    nav ul li a:hover {
        background-color: rgba(0, 0, 0, 0.1);
    }

    nav a#nav-m,
    nav a.close,
    nav #menu-wrap div {
        display: none;
    }
}