nav {
    display: block;
    width: 100%;
    color: #ffffff;
}
    nav a {
        position: relative;
        display: -webkit-flex;
        -webkit-align-items: center;
        display: flex;
        align-items: center;
        padding: 0.6vw 1vw 0.6vw 2.5vw;
        color: inherit;
        text-decoration: none;
        line-height: 0px;
        text-align: left;
        line-height: 100%;
        border-bottom: 1px solid #ffffff;
        background-image: linear-gradient(to right, rgba(255,255,255,0.3), rgba(255,255,255,0));
        background-repeat: no-repeat;
        background-size: 0%;
        transition: all linear 150ms;
    }
        nav a.active {
            background-size: 100%;
        }
        nav a:hover {
            background-size: 100%;
        }
        nav a.aFirst {
            padding: 0.6vw 1vw 0.6vw 0.8vw;
        }
        nav a span._img {
            width: 1.5vw;
            text-align: center;
        }
        nav a img {
            max-height: 0.9vw;
            max-width: 0.9vw;
            margin-right: 0.5vw;
        }
        nav a.aFirst span.arr {
            display: -webkit-flex;
            -webkit-align-items: center;
            display: flex;
            align-items: center;
            position: absolute;
            right: 1vw;
            top: 0px;
            width: 0.9vw;
            height: 100%;
        }
        nav a span.arr img {
            width: 100%;
            height: auto;
            margin-right: 0px;
            transform: rotate(90deg);
            transform-origin: center center;
        }
            nav a.active span.arr img {
                transform: none;
            }