header{
    position: fixed;
    top: 0;
    left: 0;
    z-index: 11;
    width: 100%;
    height: 75px;
    background-color: #fff;
    transition:all .3s linear;
    box-shadow: 0 0 2px #eee;
}
header.hidden{
    top: -75px;
}
header .logo img{
    margin-top: 10px;
    height: 52px;
}
header .nav{
    display: block;
}
header .nav> ul> li{
    float: left;
    line-height: 75px;
    margin-left: 40px;
    position: relative;
}
header .nav> ul> li> a{
    display: block;
    color: #546e7a;
}
header .nav> ul> li:hover> a{
    color: #2c90ff;
}
header .nav> ul> li.on> a{
    color: #2c90ff;
    font-weight: bold;
}
.menu_btn{
    width: 26px;
    height: 22px;
    margin-top: 24px;
    cursor: pointer;
    display: none;
    position: relative;
}
.menu_btn span{
    display: inline-block;
    width: 100%;
    height: 3px;
    background-color: #565656;
    position: absolute;
    transition:all .3s linear;
}
.menu_btn span:first-child{
    top: 0;
}
.menu_btn span:nth-child(2){
    top: 10px;
}
.menu_btn span:last-child{
    top: 20px;
    width: 70%;
}
.menu_btn.toggle span:first-child{
    top: 11px;
    transform: rotate(45deg);
}
.menu_btn.toggle span:nth-child(2){
    opacity: 0;
}
.menu_btn.toggle span:last-child{
    top: 11px;
    width: 100%;
    transform: rotate(-45deg);
}


footer{
    background: #fafbfd;
    padding: 3rem 0;
}
footer .top .fl{
    width: 75%;
}
footer .top ul{
    float: left;
    width: 25%;
    position: relative;
}
footer .top ul:last-child{
    margin-right: 0;
}
footer .top ul li{
    font-size: 16px;
    color: #546e7a;
    margin-bottom: 8px;
}
footer .top ul li a:hover{
    opacity: .8;
}
footer .top ul> li{
    color: #000;
    margin-bottom: 20px;
    pointer-events: none;
}
footer .top .fr{
    width: 25%;
    font-size: 14px;
    text-align: center;
}
footer .top .fr .logo{
    display: inline-block;
}
footer .top .fr .logo img{
    height: 52px;
}
footer .btm{
    margin-top: 40px;
    padding-top: 40px;
    color: #546E7A;
    border-top: 1px solid #eee;
}
footer .btm ul li{
    float: left;
    margin-right: 20px;
}
footer .btm ul li a:hover{
    opacity: .8;
}
footer .btm .fr{
    font-size: 12px;
    text-align: right;
}



@media screen and (max-width: 1440px){
    
    footer .btm{
        padding-top: 30px;
    }
}

@media screen and (max-width: 980px){
    header .logo img{
        height: 42px;
        margin-top: 16px;
    }
    .menu_btn{
        display: block;
    }
    header .nav{
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        height: 0;
        overflow: hidden;
        background-color: #fff;
        transition:all .3s linear;
    }
    header .nav.toggle{
        height: 100vh;
    }
    header .nav> ul{
        padding: 0 10%;
    }
    header .nav> ul> li{
        float: none;
        border-bottom: 1px solid #f5f5f5;
        margin-left: 0;
    }

    footer .top .fl,
    footer .top ul,
    footer .top ul li{
        width: 100%;
    }
    
    footer .top ul{
        margin-right: 0;
        border-bottom: 1px solid #f5f5f5;
    }
    footer .top ul> li:after{
        content: "+";
        position: absolute;
        top: 0;
        right: 0;
    }
    footer .top ul> li.toggle:after{
        content: "-";
    }
    footer .top ul> li{
        line-height: 50px;
        margin-bottom: 0;
        pointer-events: auto;
    }
    footer .top ul .sub{
        display: none;
    }

    footer .top .fr{
        width: 100%;
        margin-top: 15px;
    }
    footer .btm ul{
        width: 100%;
        text-align: center;
        margin-bottom: 15px;
    }
    footer .btm ul li{
        float: none;
        display: inline-block;
    }
    footer .btm .fr{
        width: 100%;
        text-align: center;
    }
}