.download-btn.ready {
    background-color: #6c757d;
    cursor: pointer;
    opacity: 0.7;
}

.download-btn.open {
    font-weight: bold;
}

.download-btn.ready span {
    color: #ffffff;
}

/* 타이틀 좌측 아이콘 스타일 */
.card-header-with-img {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
    text-align: left;
}

.book-icon-container {
    flex-shrink: 0;
    width: 70px;
    /* 크기 축소 */
    filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.1));
    transition: transform 0.3s ease;
}

.pdf-card:hover .book-icon-container {
    transform: scale(1.1) rotate(-5deg);
}

.book-icon-img {
    width: 100%;
    height: auto;
    border-radius: 4px;
}

.title-text-group {
    flex: 1;
}

.pdf-card .card-title {
    font-size: 2.0rem;
    margin: 0;
    text-align: left;
}

.pdf-card .card-subtitle {
    font-size: 1.25rem;
    margin: 0.25rem 0 0;
    text-align: left;
}

.pdf-card {
    padding: 1.25rem;
}

.update-info-card {
    margin-top: 2.5rem;
    padding: 1.5rem;
    background: linear-gradient(135deg, #ffffff 0%, #f8faff 100%);
    border: 1px solid #eef2ff;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.03);
    text-align: left;
}

.update-info-title {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.125rem;
    font-weight: 700;
    color: #1e293b;
    margin-bottom: 1rem;
}

.update-info-title svg {
    width: 20px;
    height: 20px;
    color: var(--primary-color);
}

.update-info-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.update-info-item {
    position: relative;
    padding-left: 1.25rem;
    font-size: 0.95rem;
    color: #64748b;
    line-height: 1.6;
    margin-bottom: 0.5rem;
}

.update-info-item::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0.6rem;
    width: 4px;
    height: 4px;
    background-color: #cbd5e1;
    border-radius: 50%;
}

.update-info-item strong {
    color: #334155;
    font-weight: 600;
}

@media (max-width: 420px) {
    .book-bg-container {
        width: 120px;
        left: -20px;
    }

    .update-info-card {
        padding: 1.25rem;
    }
}