/* ================== TOPに戻るボタン ================== */
        .back-to-top {
            position: fixed;
            right: 20px;
            bottom: 20px;
            width: 55px;
            height: 55px;
            border: none;
            border-radius: 50%;
            background-color: #e769dd;
            color: #ffffff;
            font-size: 24px;
            font-weight: bold;
            cursor: pointer;
            box-shadow: 0 4px 10px rgba(0, 0, 0, 0.25);
            z-index: 999;
            opacity: 0;
            visibility: hidden;
            transition: 0.3s;
        }

        .back-to-top:hover {
            background-color: #c84fc0;
        }

        .back-to-top.show {
            opacity: 1;
            visibility: visible;
        }

        html {
            scroll-behavior: smooth;
        }

        /*トップに戻るボタンは個別CSS化されています*/