/*这是第二种的banner实现方式*/

.div_banner {
    width: 100%;
    height: 333px;
    padding: 0;
    display: -webkit-flex;
    display: flex;
    align-items: center;
}

.btn_shift {
    width: 40px;
    height: 80px;
    margin: 0;
    padding: 0;
    border: none;
    display: inline-block;
    text-align: center;
    align-items: center;
    text-decoration: none;
    font-size: 35px;
    visibility: hidden;
    background-color: #111;
    opacity: 0.7;
    -webkit-transition-duration: 0.5s;
    transition-duration: 0.5s;
    cursor: pointer;
    z-index: 8999;
}

.btn_shift:hover {
    background-color: #efefef;
    opacity: 0.7;
}

.img_banner {
    width: 100%;
    height: 333px;
    max-height: 333px;
    flex: 1;
    margin-left: -40px;
    margin-right: -40px;
    cursor: pointer;
}