.navigation{
    height: 40px;
    position: sticky;
    top: 0;
    left: 0;
    right: 0;
    /* 字体，颜色，大小 */
    color: rgb(0, 0, 0);
    margin-right: 100px;
    z-index: 999;
}
.center{
    width: 70%;
    margin: auto;
    
}
.navi-bar
{

    background-color: aliceblue;
    width: 800px;
    height: 40px;
    float: right;

    border-radius: 15px;
    

}

ul {
    position: relative;
    right: 30px;
    color: #AFC5B6;
    font-weight: 700;
    font-size: 20px;
    line-height: 40px;
}
ul a{
    color: #AFC5B6;
    font-weight: 700;
    text-decoration: none;
}
ul a:hover{
    color: #EEC9C9;
}

.navigation ul{

    display: flex;
    justify-content: space-between;   
    text-decoration: none;  
    text-align: center;
    list-style: none;   /* 起始均匀对齐 */
}
.logo{
    position: relative;
    top: -0.5vw;
}

.drop{
    

    cursor:pointer;
    margin-right: 10px;
    min-width: 110px;
    border-top-left-radius: 15px;
    border-top-right-radius: 15px;

}
.drop:nth-last-child(1){
    margin-right: 0px;

}
.drop a{
    height: auto;
    width: auto;
}
.drop:hover{
    display: block;
    background-color: rgb(170, 245, 255);
    transition: all 0.4s; 
    line-height: 40px;
    height: 40px;    /* 这里要变自身颜色，还没有设计 */
}
.drop ol{
    transform-origin: top;
    transform: scaleY(0);
    display: hidden;
    list-style: none;
    border-bottom-left-radius: 12px;
    border-bottom-right-radius: 12px;
    border-top-right-radius: 12px;
    background-color: rgb(225, 255, 191);
    width: 180%;
}
.drop ol li{
    border-bottom: 1px solid rgba(0, 0, 0, 0.548);
}
.drop ol li:nth-last-child(1){
    border-bottom: none;
}
.drop:hover ol{
    transform: scaleY(100%);
    transition: all 0.4s;
    display: block;
}
.drop ol li:hover{
    background-color:rgba(0, 0, 0, 0.12);
}
.drop::before{
    content: "";
    position: absolute;
    top:15px;

    height: 0;
    width: 0;
    border-top: 12px solid gold;
    border-left: 12px solid transparent;
    border-right: 12px solid transparent;
    border-bottom: 12px solid transparent;
    z-index: 1000;
    transform: translateX(-30px);
    transform-origin: -0px 5px;
    transition: all ease-in-out 0.3s;
}
.first-one::before{
    display: none;
}
/* .drop::before{
    content: "";
    position: absolute;
    top:15px;

    height: 0;
    width: 0;
    border-top: 12px solid gold;
    border-left: 12px solid transparent;
    border-right: 12px solid transparent;
    border-bottom: 12px solid transparent;
    z-index: 1000;
    transform: translateX(-30px);
    transform-origin: -0px 5px;
    transition: all ease-in-out 0.3s;

}这种选择无法选择某一个元素
.drop:first::before{
    display: none;
} */
.drop:hover::before{
    transform: rotate(180deg);

}