.btn-back {
    margin-left:1.5em;
    display: inline-block;
    padding: 10px 24px;
    font-size: 16px;
    font-weight: bold;
    text-align: center;
    text-decoration: none;
    border-radius: 8px;
    border: none;
    cursor: pointer;
    transition: background-color 0.3s, color 0.3s;
    -webkit-user-select: none; /* テキスト選択を無効に */
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}
.style-icon-large-arrow {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background-color: #007bff;
    color: #ffffff;
    position: relative;
    padding-left: 50px;
    overflow: hidden;
}
.style-icon-large-arrow:hover { background-color: #0056b3; }

.style-icon-large-arrow .icon {
    width: 3em;
    height: 3em;

    position: absolute;
    left: 0px;
    top: 50%;
    transform: translateY(-50%);
    transition: left 0.3s ease;
}

.style-icon-large-arrow::before {
    content: '';
    /* ★こちらもフォントサイズの1.5倍に設定 */
    width: 3em;
    height: 3em;

    position: absolute;
    left: 12px;
    top: 50%;
    transform: translateY(-50%) translateX(-150%);
    transition: transform 0.3s ease, left 0.3s ease;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='%23ffffff'%3E%3Cpath d='M15.41 7.41L14 6l-6 6 6 6 1.41-1.41L10.83 12z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-size: contain;
}

.style-icon-large-arrow:hover .icon {
    left: 10px;
}
.style-icon-large-arrow:hover::before {
    transform: translateY(-50%) translateX(0);
    left: -2px;
}
a.btn-back:visited, a.btn-back:hover, a.btn-back:active {
    color: white;
}