.bigimg {
    width: 70%;
    position: fixed;
    left: 0;
    top: 0;
    right: 0;
    bottom: 0;
    margin: auto;
    display: none;
    z-index: 9999;
    border: 10px solid #fff;
}

@media screen and (max-width: 767px) {
    .bigimg { width: 92%; }
}

.mask {
    position: fixed;
    left: 0;
    top: 0;
    right: 0;
    bottom: 0;
    background-color: #000;
    opacity: 0.5;
    filter: Alpha(opacity=50);
    z-index: 999;
    transition: all 1s;
    display: none;
}

.mask:hover {
    cursor: zoom-out;
}

.mask>img {
    position: fixed;
    right: 10px;
    top: 10px;
    width: 60px;
}

.mask>img:hover {
    cursor: pointer;
}