main{
    width: 100%;
    margin-top: 30px;
    flex-wrap: wrap;/*弹性换行*/
    /* background-color: khaki; */
}
main > ul:first-of-type{
    display: flex;/*弹性盒模型*/
    position: relative;/*相对定位*/
    width: 1903px;
    height: 120px;
    margin-bottom: 60px;
    /* background-color: rgb(0, 0, 0); */
}
main > ul:first-of-type > li:first-of-type{
    width: 470px;
    height: 120px;
    background:linear-gradient(90deg,cyan 0%,cyan 10%,
    rgb(0, 93, 93) 90%,rgb(0, 93, 93) 100%)bottom right/470px 120px no-repeat;
}
main > ul:first-of-type > li:nth-child(2){
    position: absolute;/* 绝对定位 */
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    z-index:1;/* 定位层级 */
    width: 1063px;
    height: 90px;
    margin: auto;
    background-color: rgb(0, 165, 165);
    font-size:50px;/*字体大小*/
    color: rgb(255, 254, 254);
    line-height:80px;/*字体垂直居中*/
    text-align:center;/*字体水平居中*/
}
main > ul:first-of-type > li:last-of-type{
    width: 470px;
    height: 120px;
    margin-left: 963px;
    background:linear-gradient(90deg,rgb(0, 93, 93) 0%,rgb(0, 93, 93) 10%,
    cyan 90%,cyan 100%)bottom right/470px 120px no-repeat;
}
/* main > ul:first-of-type > li.construction-title{
    top: 18px;
    width: 84px;
    height: 84px;
    transform: rotate(-45deg)
} */