.chapter-index {
    position: fixed;
    left: 20px;
    top: 120px;
    width: 215px;
    background: rgba(255, 255, 255, 0.95);
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    padding: 20px;
    z-index: 1000;
}

.chapter-index h3 {
    margin: 0 0 15px 0;
    font-size: 1.1rem;
    color: #333;
    border-bottom: 1px solid #e0e0e0;
    padding-bottom: 8px;
}

.chapter-item {
    margin-bottom: 15px;
}

.chapter-item:last-child {
    margin-bottom: 0;
}

.chapter-link {
    display: block;
    color: #333;
    text-decoration: none;
    font-weight: normal;
    font-size: 0.95rem;
    line-height: 1.3;
    transition: color 0.2s ease;
}

.no-block {
    display: inline;
}

.chapter-link:hover {
    color: #0066cc;
}

.chapter-link.current {
    font-weight: bold;
    color: #0066cc;
}

.chapter-description {
    display: block;
    color: #666;
    font-size: 0.8rem;
    margin-top: 3px;
    line-height: 1.2;
}

@media (max-width: 1365px) {
    .chapter-index {
        display: none;
    }
}