.articlebox .contentbox h3 {
    margin-top: 25px;
    font-size: 17px;
    letter-spacing: 0.05em;
    font-weight: bold;
    line-height: 1em;
}
.articlebox div.titlebox + div.textbox .contentbox p {
    margin-top: 20px;
}

@media (max-width:600px){
    .sectionbox .titlebox h2 span{
        display:block;
    }
    .articlebox .contentbox h3 {
        margin-top: 20px;
        font-size: 15px;
        line-height: 1em;
        letter-spacing: 0.03em;
        padding: 0 20px;
    }
.articlebox div.titlebox + div.textbox .contentbox h3 + p {
    margin-top: 10px;
}

    .articlebox .contentbox p {
        font-size: 15px;
        letter-spacing: 0.03em;
        line-height: 25px;
        padding: 0 20px;
    }
}