:root {

}

.darken-bg {
    animation: background-fade .5s forwards;
    height: 100%;
    left: 0;
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
}

@keyframes background-fade {
    from {
        background: transparent;
    }

    to {
        background: rgba(0, 0, 0, 0.83);
    }
}