.app-update {
    background: url("img/app-update.png");
    background-size: 100% 100%;
    width: 100%;
    height: height("app-update.png");

    button {
        position: absolute;
        left: 50%;
        bottom: 220px;
        height: 90px;
        width: 470px;
        margin-left: -235px;
        padding: 0;
        background: #444;
        color: #fff;
        font-size: 30px;
        border-radius: 10px;
    }
}