@media only screen and (max-width: 430px){
    /*--------   main   --------*/
    #maincont{
        width: 100%;
        margin-top: 2em;
        padding-top: 0;
    }
    
    /*--------   logo   --------*/
    #logo{
        text-align: center;
        width: 100%;
        height: 250px;
    }

    #logo img{
        width: 160px;
    }

    #logo img:nth-child(1){
        width: 130px;
        position: initial;
    }

    /*--------   contents   --------*/
    #maincont p{
        margin: auto 2px;
    }

    /*--------   sns   --------*/
    #sns img{
        width: 130px;
    }
}

@media only screen and (max-width: 300px){
    /*--------   main   --------*/
    #maincont{
        width: 300px;
        margin-top: 7em;
        padding-top: 0;
    }
}