.pc_box a{
    display: block;
    margin:0 auto;
    background-color: dimgray;
    line-height: 1.6;
    padding:10px;
    text-decoration: underline;
    text-align: center;
    font-size: 20px;
    color: #fff;
}


@media screen and (max-width: 769px) {
    
    .pc_box a{
        text-align: left;
        padding:2vw;
        font-size: 4vw;
        margin: auto -8px;
    }

}