html{
    font-family: PingFangSC-Medium, PingFang SC;
}
header {
    width: 100%;
}

*{
    padding: 0 ;
    margin:  0;
}
.core{
    width: 1200px;
    margin: 0 auto;
    height: 100%;
    position: relative;
}
.nav_box{
    width: 100%;
    height: 70px;
    display: flex;
    align-items: center;
    flex-direction: row;
    justify-content: space-between;
}
.nav_box ul{
    display: flex;
}
.nav_box li{
    white-space: nowrap;
    list-style:none;
    font-size: 18px;
    margin-left: 45px;
    font-weight: 500;
}
.nav_box a{
    text-decoration:none;
    color: #4A4A4A;
    font-size: 18px;
}
.nav_box ul li:nth-child(4){
    color: #E33B38;
}
.nav_box ul button{
    width: 90px;
    height: 28px;
    background: #E33B38;
    border-radius: 4px;
    border:none;
    color:#fff;
    font-size: 16px;
}