.menubut{
    display: none;
}
#back{
    display: none;
}
#backg{
    background-color: rgba(0, 0, 0, 0.5);
    width: 100%;
    height: 100%;
    position: fixed;
    top:0;
    left: 0;
    display: none;;
}
#sec_menu{
    display: none;
}
@media screen and (max-width:960px){
    #side{
        width:100%;
    }
    header li a{
        width: auto;
    }
}
@media screen and (max-width:580px){
    .button{
        width: 100%;
    }
    img{
        float: left;
    }
    .menubut{
        display: block;
        float: right;
    }
    #side{
        width:90%;
    }
    #back{
        display: block;
    }
    #sec_menu{
        display: block;
    }
    aside{
        display: none;
        position: fixed;
        top:0px;
        right:0px;
        height: 100%;
        width: 50%;
    }
    nav{
        display: none;
        height: 100%;
        width: 50%;
        position: fixed;
        top:0px;
        right:0px;
    }
    header li, header li a, #home{
        display: block;
        width:100%;
        height:12%;
    }
    main{
        clear: both;
        width: 95%;
        margin: 0 auto;
        padding:0;
    }
}