@media only screen and (max-width: 414px) {
    #bg-mainvisual {
        height: 425px;
    }
    #mainvisual-sp-wrap {
        display: block;
        position: relative;
        height: 450px;
    }
    .mainvisual-sp-txtbox::before {
        content: "";
        position: absolute;
        top: -26%;
        left: 3.6vw;
        width: 180px;
        height: 80px;
        background: url('https://www.kaitaikozi-progress.com/wp-content/themes/ihinzenkoku/img/medal.png') center center no-repeat;
        background-size: contain;
    }
}