body{font-family: "A1 Gothic M";}

 @media (min-width: 641px) {
    #talk_body .txt_box {
        max-width: 700px;
        padding: 40px;
        margin: 20px auto 60px auto;
        box-sizing: border-box;
        border-radius: 20px;
    }
}

@media (max-width: 640px) {
    #talk_body .txt_box {
        max-width: 480px;
        padding: 15px 15px 35px 15px;
        margin: calc(20 / 640 * 100vw) auto calc(60 / 640 * 100vw) auto;
        box-sizing: border-box;
        border-radius: 20px;
    }
}

@media (min-width: 641px) {
    #talk_body .pic .caption {
        color: #919191;
    }
}

@media (max-width: 640px) {
    #talk_body .pic .caption {
        color: #919191;
    }
}