#loading.show {
    display: flex;
    // 显示时动画
    animation: loading-show .3s ease-in-out
}

#loading.before-hide {
    // 隐藏前动画
    animation: loading-hide .3s ease-in-out
}

#loading.hide {
    // 隐藏
    display: none
}

@keyframes loading-show {
    0% {
        opacity: 0
    }

    100% {
        opacity: 1
    }
}

@keyframes loading-hide {
    0% {
        opacity: 1
    }

    100% {
        opacity: 0
    }
}