.book-header {
    padding: var(--space-16) 0 var(--space-12);
    background: var(--color-bg-grouped);
    border-bottom: 1px solid var(--color-separator);
}

.breadcrumb {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-size: var(--text-footnote);
    color: var(--color-text-secondary);
    margin-bottom: var(--space-6);
}

.breadcrumb a {
    color: var(--color-text-secondary);
}

.breadcrumb a:hover,
.breadcrumb a:focus-visible {
    color: var(--color-link);
}

.breadcrumb-logo {
    display: inline-flex;
    align-items: center;
}

.breadcrumb-logo img {
    width: var(--space-6);
    height: var(--space-6);
    display: block;
    border-radius: var(--radius-sm);
}

.breadcrumb-separator {
    color: var(--color-text-tertiary);
}

.breadcrumb-current {
    color: var(--color-text-primary);
    font-weight: var(--weight-medium);
}

.book-subtitle {
    font-size: var(--text-subhead);
    font-weight: var(--weight-semibold);
    text-transform: uppercase;
    letter-spacing: var(--tracking-wide);
    color: var(--color-text-secondary);
    margin: 0 0 var(--space-2);
}

.book-header h1 {
    font-size: clamp(2.75rem, 6vw, 4.5rem);
    margin: 0 0 var(--space-3);
}

.book-byline {
    font-style: italic;
    color: var(--color-text-secondary);
    margin: 0;
}

.book {
    padding: var(--space-16) 0 var(--space-24);
}

.book-layout {
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: var(--space-12);
    align-items: start;
}

.book-aside {
    position: sticky;
    top: var(--space-8);
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
}

.book-aside-cover {
    width: 100%;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
}

.book-aside-authors {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
    margin-top: var(--space-4);
    padding-top: var(--space-4);
    border-top: 1px solid var(--color-separator-light);
}

.author-card {
    display: flex;
    align-items: flex-start;
    gap: var(--space-3);
}

.author-photo {
    flex-shrink: 0;
    width: 56px;
    height: 56px;
    border-radius: 50%;
    object-fit: cover;
    background: var(--color-bg-grouped);
    display: flex;
    align-items: center;
    justify-content: center;
}

.author-photo-initials {
    font-family: var(--font-sans);
    font-size: var(--text-headline);
    font-weight: var(--weight-semibold);
    color: white;
    background: linear-gradient(
        135deg,
        var(--color-system-blue) 0%,
        var(--color-system-purple) 100%
    );
    letter-spacing: -0.02em;
}

.author-info {
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
    min-width: 0;
}

.author-name {
    font-size: var(--text-callout);
    font-weight: var(--weight-semibold);
    color: var(--color-text-primary);
    margin: 0;
    line-height: 1.2;
}

.author-title {
    font-size: var(--text-footnote);
    color: var(--color-text-secondary);
    margin: 0;
    line-height: 1.3;
}

.author-socials {
    list-style: none;
    margin: var(--space-1) 0 0;
    padding: 0;
    display: flex;
    gap: var(--space-2);
}

.author-social {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    color: var(--color-text-secondary);
    background: var(--color-fill-quaternary);
    transition:
        color var(--duration-fast) var(--ease-standard),
        background-color var(--duration-fast) var(--ease-standard);
}

.author-social:hover,
.author-social:focus-visible {
    color: var(--color-text-primary);
    background: var(--color-fill-tertiary);
}

.author-social svg {
    width: 14px;
    height: 14px;
    display: block;
}

.book-content {
    display: flex;
    flex-direction: column;
    gap: var(--space-6);
}

.book-content h1,
.book-content h2,
.book-content h3,
.book-content h4,
.book-content h5,
.book-content h6 {
    font-family: var(--font-sans);
}

.book-content h2 {
    font-size: var(--text-title-1);
    margin-top: var(--space-6);
}

.book-content h2:first-child {
    margin-top: 0;
}

.book-content p {
    color: var(--color-text-primary);
}

@media (max-width: 900px) {
    .book-layout {
        grid-template-columns: 1fr;
        gap: var(--space-8);
    }

    .book-aside {
        position: static;
        flex-direction: row;
        align-items: center;
        gap: var(--space-5);
    }

    .book-aside-cover {
        width: 140px;
        flex-shrink: 0;
    }
}

.books-index {
    padding: var(--space-16) 0 var(--space-24);
}

.books-index-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--space-20) var(--space-12);
    list-style: none;
    margin: 0;
    padding: var(--space-12) 0;
}

.books-index-grid > li {
    display: flex;
    overflow: visible;
}

.books-index-grid .book-card {
    width: 100%;
    flex-shrink: 1;
    overflow: visible;
}