*{
  margin: 0;
  padding: 0;
  box-sizing: border-box;  
}
body{
    background: #eee;
}

/* 添加关键帧 */
@keyframes spin {
    from {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(360deg);
    }
}
#baGua{
    /* border: 2px solid red; */
    width: 400px;
    height: 400px;
    border-radius: 50%;
    position: relative;
    overflow: hidden;
    animation: spin 5s infinite linear; /* 增加CSS旋转属性 */
    box-shadow: -1px 0px 13px 3px rgba(0,0,0,0.6);
}
@media (max-width: 500px){
    #baGua{
        width: 200px;
        height: 200px;
    }
}

#baGua>div:first-child {
    /* border: 2px solid blue; */
    position: absolute;
    float: left;
    width: 50%;
    height: 100%;
    background: black;
}
#baGua>div:nth-child(2){
    /* border: 2px solid yellow; */
    position: absolute;
    right: 0;
    width: 50%;
    height: 100%;
    background: white;
}
#baGua>div:nth-child(3){
    /* border: 2px solid yellow; */
    position: absolute;
    border-radius: 50%;
    right: 0;
    width: 200px;
    height: 200px;
    left: 50%;
    margin-left: -100px;
    background: black;
}
@media (max-width: 500px){
    #baGua>div:nth-child(3){
        width: 100px;
        height: 100px;
        margin-left: -50px;
    }
}

#baGua>div:nth-child(4){
    /* border: 2px solid yellow; */
    position: absolute;
    border-radius: 50%;
    right: 0;
    width: 200px;
    height: 200px;
    left: 50%;
    margin-left: -100px;
    bottom: 0;
    background: white;
}
@media (max-width: 500px){
    #baGua>div:nth-child(4){
        width: 100px;
        height: 100px;
        margin-left: -50px;
    }
}

#baGua>div:nth-child(5){
    /* border: 2px solid yellow; */
    position: absolute;
    border-radius: 50%;
    right: 0;
    width: 50px;
    height: 50px;
    left: 50%;
    top: 75px;
    margin-left: -25px;
    background: white;
}
@media (max-width: 500px){
    #baGua>div:nth-child(5){
        width: 25px;
        height: 25px;
        top: 37.5px;
        margin-left: -12.5px;
    }
}

#baGua>div:nth-child(6){
    /* border: 2px solid yellow; */
    position: absolute;
    border-radius: 50%;
    right: 0;
    width: 50px;
    height: 50px;
    left: 50%;
    bottom: 75px;
    margin-left: -25px;
    background: black;
}
@media (max-width: 500px){
    #baGua>div:nth-child(6){
        width: 25px;
        height: 25px;
        bottom: 37.5px;
        margin-left: -12.5px;
    }
}


#baGua-description{
    /* border:  2px solid red; */
    margin-top: 1em;
    font: normal bold 20px "微软雅黑";
}
#baGuaWrapper{
    /* border: 2px solid red; */
    height: 100vh; /* 此处写100%不可以实现，vh: viewpoint用户可视范围。 */
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column; /*让文字与八卦竖向排开 */

}