.book-detail-hero {
    padding: 36px 0 70px;
    background:
        radial-gradient(
            circle at 85% 18%,
            rgba(33, 103, 213, 0.16),
            transparent 30%
        ),
        radial-gradient(
            circle at 10% 85%,
            rgba(255, 122, 26, 0.13),
            transparent 25%
        ),
        #f4f7fb;
}

.detail-breadcrumb {
    display: flex;
    gap: 9px;
    margin-bottom: 32px;
    color: #8791a4;
    font-size: 13px;
}

.detail-breadcrumb a {
    color: #2167d5;
    text-decoration: none;
}

.detail-breadcrumb strong {
    color: #485469;
}

.book-detail-grid {
    display: grid;
    grid-template-columns: minmax(260px, 390px) minmax(0, 1fr);
    align-items: center;
    gap: 70px;
}

.detail-cover {
    display: flex;
    width: 100%;
    aspect-ratio: 3 / 4;
    flex-direction: column;
    justify-content: flex-end;
    overflow: hidden;
    padding: 30px;
    border-radius: 18px;
    background: linear-gradient(145deg, #123565, #2167d5);
    color: #ffffff;
    box-shadow: 0 30px 70px rgba(7, 25, 54, 0.25);
}

.detail-cover.has-image {
    display: block;
    height: auto;
    padding: 0;
    aspect-ratio: auto;
    background: transparent;
}

.detail-cover img {
    display: block;
    width: 100%;
    max-width: none;
    height: auto;
    margin: 0;
    object-fit: contain;
}

.detail-cover > span {
    margin-bottom: 14px;
    color: #bcd3ff;
    font-weight: 800;
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

.detail-cover > strong {
    font-size: 35px;
    line-height: 1.05;
}

.detail-content h1 {
    max-width: 850px;
    margin: 17px 0 13px;
    color: #071936;
    font-size: clamp(44px, 6vw, 76px);
    line-height: 0.98;
    letter-spacing: -0.055em;
}

.detail-author {
    margin: 0;
    color: #657086;
    font-size: 17px;
}

.detail-author strong {
    color: #293246;
}

.detail-stats {
    display: grid;
    grid-template-columns: repeat(3, minmax(120px, 1fr));
    gap: 12px;
    margin: 28px 0;
}

.detail-stats article {
    padding: 16px;
    border: 1px solid #dfe5ed;
    border-radius: 14px;
    background: rgba(255, 255, 255, 0.78);
}

.detail-stats strong,
.detail-stats span {
    display: block;
}

.detail-stats strong {
    color: #071936;
    font-size: 17px;
}

.detail-stats span {
    margin-top: 4px;
    color: #657086;
    font-size: 12px;
}

.detail-description {
    max-width: 820px;
    color: #485469;
    font-size: 17px;
    line-height: 1.8;
}

.detail-description p {
    margin: 0 0 12px;
}

.access-notice,
.free-notice {
    margin-top: 22px;
    padding: 14px 16px;
    border-radius: 12px;
}

.access-notice {
    border: 1px solid #b8dfca;
    background: #e8f8f0;
    color: #0e7345;
}

.access-notice strong,
.access-notice span {
    display: block;
}

.access-notice span {
    margin-top: 3px;
    font-size: 13px;
}

.free-notice {
    border: 1px solid #cbd9ee;
    background: #eaf2ff;
    color: #174984;
}

.detail-actions {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 11px;
    margin-top: 28px;
}

.detail-actions form {
    margin: 0;
}

.detail-actions button {
    font: inherit;
    cursor: pointer;
}

.detail-like {
    display: grid;
    width: 52px;
    height: 52px;
    place-items: center;
    border: 1px solid #d7dce5;
    border-radius: 14px;
    background: #ffffff;
    color: #2167d5;
    font-size: 24px;
}

.detail-like.liked {
    border-color: #ffd2b2;
    background: #fff0e4;
    color: #ff7a1a;
}

.detail-messages {
    display: grid;
    gap: 8px;
    margin-bottom: 20px;
}

.detail-message {
    padding: 13px 16px;
    border: 1px solid #b8dfca;
    border-radius: 12px;
    background: #e8f8f0;
    color: #0e7345;
    font-weight: 700;
}

.chapter-preview-section {
    padding: 72px 0;
    background: #ffffff;
}

.chapter-preview-grid {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 350px;
    align-items: start;
    gap: 60px;
}

.chapter-list {
    display: grid;
    gap: 10px;
    margin-top: 27px;
}

.chapter-list article {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 16px 18px;
    border: 1px solid #e1e5ec;
    border-radius: 14px;
    background: #fafbfd;
}

.chapter-list article > span {
    display: grid;
    width: 42px;
    height: 42px;
    flex: 0 0 42px;
    place-items: center;
    border-radius: 12px;
    background: #eaf2ff;
    color: #2167d5;
    font-weight: 900;
}

.chapter-list strong,
.chapter-list small {
    display: block;
}

.chapter-list strong {
    color: #071936;
}

.chapter-list small {
    margin-top: 3px;
    color: #8791a4;
}

.reading-panel {
    position: sticky;
    top: 30px;
    padding: 30px;
    border-radius: 20px;
    background: #071936;
    color: #ffffff;
    box-shadow: 0 20px 50px rgba(7, 25, 54, 0.18);
}

.reading-panel > span {
    font-size: 34px;
}

.reading-panel h2 {
    margin: 18px 0 12px;
    font-size: 30px;
    line-height: 1.05;
}

.reading-panel p {
    margin: 0 0 23px;
    color: #bdc9db;
    line-height: 1.7;
}

.reading-panel .button {
    width: 100%;
}

.reading-plan-link {
    display: block;
    margin-top: 17px;
    color: #ffffff;
    font-size: 13px;
    font-weight: 800;
    text-align: center;
}

@media (max-width: 950px) {
    .book-detail-grid {
        grid-template-columns: 280px minmax(0, 1fr);
        gap: 38px;
    }

    .detail-stats {
        grid-template-columns: 1fr;
    }

    .chapter-preview-grid {
        grid-template-columns: 1fr;
    }

    .reading-panel {
        position: static;
    }
}

@media (max-width: 700px) {
    .book-detail-grid {
        grid-template-columns: 1fr;
    }

    .detail-cover {
        max-width: 330px;
        margin: 0 auto;
    }

    .detail-content {
        text-align: center;
    }

    .detail-description {
        text-align: left;
    }

    .detail-actions {
        justify-content: center;
    }

    .detail-stats {
        text-align: left;
    }
}