a, button {
    margin: 0;
    padding: 0;
    border: 0;
    outline: 0;
    appearance: none;
    box-sizing: border-box;
    cursor: pointer;
}

.slider {
    height: 491px;
    overflow: hidden;
    position: relative
}
.pointer {
    position: absolute;
    bottom: 0px;
    width: 100%;
    z-index: 4;
    text-align: center
}
.pointer>li {
    display: inline-block;
    width: 10px;
    height: 10px;
    cursor: pointer;
    border-radius: 50%;
    background-color: #fff
}
.pointer>li:not(:last-child) {
    margin-right: 10px
}
.pointer>li.current {
    background-color: #007aff
}
.sliderUl {
    width: 100%;
    height: 100%;
    white-space: nowrap;
    font-size: 0;
    -webkit-transform: translateX(0);
    transform: translateX(0);
    position: absolute;
    bottom: 0
}
.sliderLi {
    width: 100%;
    height: 100%;
    display: inline-block;
    font-size: 0;
}
.slider img {
    width: 100%;
    height: 100%;
    display: block;
}
.nextBtn, .preBtn {
    position: absolute;
    top: 50%;
    left: 0;
    transform: translateY(-50%);
    width: 30px;
    height: 40px;
    line-height: 40px;
    font-size: 18px;
    text-align: center;
    background-color: rgba(0,0,0,.5);
    z-index: 10;
    color: #fff;
    font-family: "宋体";
}
.nextBtn {
    right: 0;
    left: auto
}