ul,
li {
    list-style: none;
    margin: 0;
    padding: 0;
}

.bg_left {
    width: 470px;
    height: auto;
    position: relative;
    margin: 0 auto;
    border: 1px solid #e2e2e2;
    padding: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.bg_right {
    position: absolute;
    top: 0;
    left: 463px;
    z-index: 999;
    width: 100%;
}

.show {
    width: 100%;
    height: auto;
    position: relative;
    cursor: move;
    overflow: hidden;
}

.show img {
    width: 100%;
    height: auto;
    max-width: 100%;
}

.mask {
    width: 312.5px;
    height: 216.5px;
    position: absolute;
    top: 0;
    left: 0;
    display: none;
    background: #FFF;
    -moz-opacity: 0.5;
    opacity: 0.5;
    filter: alpha(opacity=50);
    border: 1px solid #333;
}

.bigshow {
    width: 470px;
    height: 470px;
    overflow: hidden;
    margin-left: 10px;
    display: none;
}

.bigshow img {
    width: 100%;
    height: auto;
    margin-right: 10px;
    max-width: 100%;
    max-height: 100%;
}