.box {
    box-sizing: border-box;
    /* min-width: 400px; */
    min-height: 300px;
    /* background-color: #0af; */
    overflow: hidden;
    position: relative;
    /* box-shadow: 2px 2px 5px 0 #A3A3A3; */
}

.box::before {
    content: '';
    width: 500px;
    height: 300px;
    opacity: 1;
    background-image: linear-gradient(to bottom,
            rgba(255, 255, 255, 0) 0%,
            rgba(240, 232, 232, 0.3) 40%,
            rgba(255, 255, 255, 0.3) 60%,
            rgba(255, 255, 255, 0) 100%);
    transform-origin: center center;
    position: absolute;
    z-index: 10;
    animation-delay: 1s;
    animation-name: mask-ani;
    animation-duration: 5s;
    animation-iteration-count: infinite;
}

.box::after {
    content: '';
    width: 500px;
    height: 50px;
    opacity: 0;
    /* background-color: #fff; */
    transform-origin: center center;
    position: absolute;
    z-index: 1;
    animation-delay: 1s;
    animation-name: mask-border-ani;
    animation-duration: 5s;
    animation-iteration-count: infinite;
}

.box img {
    width: 100%;
    vertical-align: middle;
    z-index: 5;
    /* position: absolute; */
    top: 0;
    bottom: 0;
    left: 0;
    right: 0px;
    margin: auto;
}

@keyframes mask-ani {
    0% {
        transform: rotate(-36deg) translate(-40px, -430px);
    }

    70%,
    100% {
        transform: rotate(-36deg) translate(-40px, 378px);
    }
}

@keyframes mask-border-ani {
    0% {
        opacity: 0.8;
        transform: rotate(-36deg) translate(-126px, -190px);
    }

    70%,
    100% {
        opacity: 0.8;
        transform: rotate(-36deg) translate(-126px, 355px);
    }
}


/* ///////////////////////////////////////////////////////// */