#mainImg{
    background-image: url(../img/privacy_mainimg01.jpg);
}

#sec01{
    width: 945px;
    margin: 0 auto;
}

#sec01 h3{
    font-size: 24px;
    color: #623700;
    border-bottom: 2px solid #623700;
    margin-top: 50px;
    margin-bottom: 5px;
}

@media screen and (max-width: 600px) {
    #mainImg{
        background-image: url(../img/privacy_mainimg01_sp.jpg);
    }

    #sec01{
        width: 300px;
    }

    #sec01 h3{
        font-size: 14px;
        border-bottom: 1px solid #623700;
        padding-bottom: 5px;
        margin-top: 15px;
    }
}