.page {
    background: #fff;
    position: relative;
}

.page-number {
    position: absolute;
    bottom: 10px;
    right: 15px;
    font-size: 12px;
    color: #666;
}

/* 표지 */
.cover, .back-cover {
    background: #111;
    color: #fff;
}

.cover-inner {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
}