#TopButton {
    position: fixed;
    right: 100px;
    bottom: 50px;
    text-indent: -9999px;
    margin: 0;
    z-index: 9999;
}
#TopButton a {
    position: relative;
    display: block;
    width: 65px;
    height: 65px;
    border-radius: 100px;
    background: #3E497A;
    transition: opacity .6s ease;
}
#TopButton a:hover {
    background: #363f69;
}
#TopButton a::before {
    position: absolute;
    top: 7px;
    right: 0;
    bottom: 0;
    left: 0;
    display: block;
    width: 14px;
    height: 14px;
    margin: auto;
    content: '';
    transform: rotate(-45deg);
    border-top: 2px solid #29C7AC;
    border-right: 2px solid #29C7AC;
}
/* #region スマホ版デザイン */
@media screen and (max-width:767px) {
    #TopButton {
        position: fixed;
        right: 50px;
        bottom: 50px;
        text-indent: -9999px;
        margin: 0;
        z-index: 9999;
    }
    #TopButton a {
        width: 45px;
        height: 45px;
    }
    #TopButton a::before {
        top: 5px;
        width: 10px;
        height: 10px;
    }

}
/* #endregion */