/* * control */
main{
    position: relative;
    margin-bottom: 5rem;
}
.control{
    width: 15rem;
    height: 3rem;
    /* border: 1px solid red; */
    display: flex;
    justify-content: space-around;
    align-items: center;
    position: absolute;
    left: calc((100% - 15rem)/2);
    bottom: -4rem;
    margin: auto;
}
.control img{
    width: 1rem;
    height: 1rem;
}
.control span{
    display: inline-block;
    width: 2rem;
    height: 2rem;
    background-color: white;
    cursor: pointer;
    text-align: center;
    line-height: 2rem;
    border: 1px solid #bdbdbd;
}
/* 指示点 */
.dot{
    width: 9rem;
    height: 100%;
    
    display: flex;
    justify-content: space-around;
    align-items: center;
}
/* 默认样式 */
.dot span.active{
    background-color: #127ec3;
    /* border: 1px solid red; */
    color: white;
}