#shim {
    left: -99999px;
    position: fixed;
    width: 100%;
    height: 100%;
    z-index: 999997;
    background-color: rgba(255,255,255,0);
    transition: background-color 150ms linear;

    &.active {
        left: 0;
        background-color: rgba(42, 55, 66, 0.8);
    }
}