body {
    min-width: 0px;
}
a{
    color: black;
}
.row {
    display: flex;
    flex-direction: row;
}

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

.items {
    align-items: center;
}

.center {
    justify-content: center;
}

.spaceb {
    justify-content: space-between;
}

.nav {
    min-width: 0px;
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    position: relative;
}

.nav_left, .head_nav_list {
    display: flex;
    flex-direction: row;
}

@media screen and (max-width: 1213px) {
    .in_btn {
        display: none;
    }

    .head_nav_list {
        margin-right: 60px;
    }
}

@media screen and (max-width: 1177px) {
    .join_btn {
        margin-right: 10px;
    }
    .wechat_btn {
        display: none;
    }
}

@media screen and (max-width: 1060px) {
    .join_btn {
        margin-right: 10px;
    }

    .head_nav_list {
        margin: 0 40px;
    }

    .wechat_btn {
        display: none;
    }

    .nav {
        justify-content: center;
    }
}

@media screen and (max-width: 1000px) {
    .head_nav_list {
        margin: 0 20px;
    }
}

@media screen and (max-width: 950px) {
    .nav_right {
        display: none;
    }
}

@media screen and (max-width: 800px) {
    .logo_block {
        display: none;
    }
    .head_nav_list {
        margin-left: 0;
    }
}

.clearfix:after {
    content: ".";
    display: block;
    height: 0;
    clear: both;
    visibility: hidden;
}
.clearfix {
    *zoom: 1;
}   /* IE6、7 专有 */