@media screen and (max-width: 767px) {
    #topmenu{
        height: auto;
        position: relative;
    }
    .topmenu{
        width: 100%;
        height: auto;
    }
    .topmenu>ul{
        width: 100%;
    }
    .topmenu>ul>li{
        width: 100%;
    }
    .topmenu>ul>li>a{
        width: 100%;
        text-align: center;
        background: #144552;
        color: #f1fffa;
    }
    .topmenu>ul>li>a:hover{
        background: #f1fffa;
        color: #144552;
    }
    .search{
        width: 100%;
        margin-top: 10px;
        margin-bottom: 10px;
    }
    .search>form>input{
        width: 80%;
        margin: 0 auto;
        display: block;
    }
    #banner{
        height: 80px;
        top: 0;
        background: url('../img/banner.jpg') repeat-x;
    }
    .banner{
        position: absolute;
        line-height: 80px;
    }
    .banner>.title>a{
        color: #f1fffa;
        text-align: center;
        font-size: 24px;
    }
    .logo{
        background: url('../img/logonomymath3.png') no-repeat;
        width: 80px;
        height: 80px;
        background-size: cover;
    }
    #main_slider{
        display: none;
    }
    #far_menu{
        top: 0;
    }
    #main{
        width: 100%;
        top: 0;
    }
    .main_download{
        width: 100%;
    }
    .download_image{
        width: 90%;
    }
    .download_image>a>img{
        width: 100%;
        -webkit-object-fit: cover;
        -moz-object-fit: cover;
        -o-object-fit: cover;
    }
    .main_sidebar{
        width: 100%;
        margin-top: 30px;
    }
    #footer{
        height: auto;
    }
    .footer{
        width: 100%;
        display: block;
    }
    .footer_item{
        margin: 10px;
    }
    .footer_title{
        border-bottom: 1px solid #4d908e;
    }
}
@media screen and (min-width: 768px) and (max-width:1023px) {
    
}