.book-main {
    display: block;
}

.book-content {
    max-width: 1080px;
}

.page-content {
    padding-bottom: 0.5rem;
}

.book-home-lead,
.page-lead {
    margin-bottom: 2.5rem;
    padding: 1.75rem 1.75rem 1.25rem;
    background: linear-gradient(180deg, var(--bg-secondary), var(--bg-primary));
    border: 1px solid var(--border-color);
    border-radius: 16px;
}

.page-kicker,
.page-section-label {
    margin: 0 0 0.5rem;
}

.page-kicker {
    color: var(--primary-color);
    font-size: 0.85rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.page-section-label {
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 600;
}

.book-home-lead h1,
.page-lead h1 {
    margin-top: 0;
    margin-bottom: 0.75rem;
}

.page-deck {
    color: var(--text-secondary);
    font-size: 1.05rem;
    max-width: 56rem;
}

.lead-actions {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
    margin-top: 1.2rem;
}

.button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.7rem 1.1rem;
    border: 1px solid var(--border-color);
    border-radius: 999px;
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition);
}

.button:hover {
    text-decoration: none;
}

.button.primary {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: #fff;
}

.button.primary:hover {
    background: var(--primary-hover);
    color: #fff;
}

.button.secondary {
    background: var(--bg-primary);
    color: var(--text-primary);
}

.book-navigation {
    margin: 2rem 0 0;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.chapter-nav {
    display: flex;
    justify-content: space-between;
    align-items: stretch;
    gap: 1rem;
}

.nav-prev,
.nav-next,
.nav-home,
.nav-disabled {
    display: flex;
    flex-direction: column;
    gap: 0.2rem;
    min-height: 4.5rem;
    padding: 0.9rem 1rem;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 10px;
}

.nav-prev,
.nav-next {
    flex: 1 1 0;
}

.nav-home {
    justify-content: center;
    align-items: center;
    flex: 0 0 8rem;
}

.nav-next {
    text-align: right;
}

.nav-disabled {
    opacity: 0.5;
}

.book-navigation .label {
    color: var(--text-secondary);
    font-size: 0.85rem;
    font-weight: 700;
}

.book-navigation .title {
    color: var(--text-primary);
    font-size: 0.95rem;
    line-height: 1.45;
}

.book-footer-links {
    flex-wrap: wrap;
}

@media (max-width: 960px) {
    .chapter-nav {
        flex-direction: column;
    }

    .nav-home {
        flex: 1 1 auto;
    }
}