html {
    /* background-color: aqua; */
    padding-left: 5%;
    padding-right: 5%;
    /* padding-bottom: 150px 150px 0 0; */
    background-image: url("../img/bkgImg2.webp");
    background-size: cover;
    background-repeat: no-repeat;
}

body {
    /* 要想将页面布满窗口
    就要将body的margin和padding布满
    这样body和html之间就没有缝隙了 */
    margin: 0px;
    padding-left: 0px;
    padding-right: 0px;
    background-color: #fff;
}



/* li {
    list-style-type: none;
} */

.main {
    display:flex;
    flex-direction:column;
}

.achi, .introduction {
    display: flex!important;
    justify-content: center;
    flex-wrap: wrap;
    flex-direction: row;
}
#keep_distance {
    padding:20px;
    margin: 20px;
    width: 25%!important;
}
.achi-detail-link > p {
    margin-top: 10px;
    margin-bottom: 10px;
}
.achi-detail-link header > h2 {
    margin-top: 10px;
    margin-bottom: 10px;
}
.introduction-detail {
    padding:20px;
    margin: 20px;
    width: 70%!important;
    text-align: center;
    /* background-color: #005f5f; */
    background-color: rgb(34,70,94);
    /* background-color: #0c122b; */
    color: #fff;
    font-size: 20px;
    border-radius: 5px;
    font-family: Helvetica;
}

.achi > div {
    /* padding:10px;
    margin: 10px; */
    width: 350px;
    text-align: center;
}

.achi-detail {
    transition: .5s ease!important;
    padding:5px;
}
.achi-detail a{
    color:black;
}
.achi-detail a:hover{
    color:white;
}

.achi-detail:hover {
    /* border-bottom:15px solid #444; */
    border-bottom:15px solid #0a1533;
    /* background-color: #005f5f; */
    background-color: rgb(34,70,94);
    /* border-left:15px solid rgb(6, 11, 15);
    background-color: rgb(31, 57, 78); */
    color: white!important;
    border-radius: 5px;
}

.achi-detail > p {
    font-size: 20px;
}

#myBtn {
    display: none;
    position: fixed;
    bottom: 50px;
    right: 30px;
    z-index: 99;
    font-size: 18px;
    border: none;
    outline: none;
    background-color: red;
    color: white;
    cursor: pointer;
    padding: 15px;
    border-radius: 15px;
}

#myBtn:hover {
    background-color: black;
}
@media screen and (min-width:1000px) {
    .nav li {
        width: 120px;
        border-bottom: none;
        height: 50px;
        line-height: 50px;
        font-size: 1.4em;
    }
    .nav li {
        display: inline-block;
        margin-right:  -4px;
    }
    
}
@media screen and (max-width:1000px) {
    #myBtn {
        width: 15%;
        bottom: 60px;   
        /* height: 5%; */
    }    
}