:root {
    --primary-color: #2c7a7b;
    --secondary-color: #4fd1c7;
    --light-bg: #f7fafc;
    --text-dark: #2d3748;
}

body {
    font-family: 'Microsoft YaHei', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    color: var(--text-dark);
    background-color: var(--light-bg);
}

/* Navbar */
.navbar-book {
    background-color: white;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
    padding: 0.65rem 0;
}

.navbar-book .navbar-brand {
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--primary-color) !important;
    padding-top: 0.35rem;
    padding-bottom: 0.35rem;
}

.navbar-book .navbar-brand-logo {
    height: 2rem;
    width: auto;
    object-fit: contain;
}

.navbar-book .nav-link {
    color: var(--text-dark) !important;
    font-weight: 500;
    padding: 0.5rem 0.85rem;
    border-radius: 0.35rem;
    transition: color 0.2s ease, background-color 0.2s ease;
}

.navbar-book .nav-link:hover,
.navbar-book .nav-link:focus {
    color: var(--primary-color) !important;
    background-color: rgba(44, 122, 123, 0.06);
}

.navbar-book .navbar-toggler {
    border: 1px solid rgba(44, 122, 123, 0.35);
    padding: 0.4rem 0.55rem;
}

.navbar-book .navbar-collapse {
    padding-top: 0.5rem;
}

@media (min-width: 992px) {
    .navbar-book .navbar-collapse {
        padding-top: 0;
    }
}

.book-nav-dropdown {
    border: none;
    border-radius: 0.5rem;
    padding: 0.5rem;
    margin-top: 0.35rem !important;
    box-shadow: 0 0.5rem 1.5rem rgba(0, 0, 0, 0.12);
}

@media (min-width: 992px) {
    .book-nav-dropdown {
        min-width: 22rem;
    }

    .book-nav-dropdown.show {
        display: grid !important;
        grid-template-columns: 1fr 1fr;
        gap: 0.15rem;
    }
}

.book-nav-dropdown .dropdown-item {
    border-radius: 0.35rem;
    padding: 0.5rem 0.75rem;
    font-size: 0.9rem;
    white-space: normal;
}

.book-nav-dropdown .dropdown-item:hover,
.book-nav-dropdown .dropdown-item:focus {
    background-color: rgba(44, 122, 123, 0.1);
    color: var(--primary-color) !important;
}

.navbar-book .dropdown-toggle::after {
    margin-left: 0.35em;
    vertical-align: 0.12em;
}

@media (max-width: 991.98px) {
    .navbar-book .book-nav-dropdown {
        position: static !important;
        transform: none !important;
        float: none;
        width: 100%;
        margin-top: 0.25rem !important;
        margin-bottom: 0.5rem;
        box-shadow: none;
        border: 1px solid rgba(0, 0, 0, 0.08);
    }

    .navbar-book .book-nav-dropdown.show {
        display: grid !important;
        grid-template-columns: 1fr;
    }
}

#bookCarousel .carousel-inner {
    overflow: hidden;
}

#bookCarousel .book-carousel-slide {
    min-height: 190px;
    background-size: cover;
    background-position: center;
    position: relative;
}

@media (min-width: 576px) {
    #bookCarousel .book-carousel-slide {
        min-height: 260px;
    }
}

@media (min-width: 768px) {
    #bookCarousel .book-carousel-slide {
        min-height: 340px;
    }
}

@media (min-width: 992px) {
    #bookCarousel .book-carousel-slide {
        min-height: 380px;
    }
}

#bookCarousel .book-carousel-slide::before {
    content: "";
    position: absolute;
    inset: 0;
    background: linear-gradient(
        135deg,
        rgba(61, 48, 41, 0.5) 0%,
        rgba(74, 85, 104, 0.45) 50%,
        rgba(45, 55, 72, 0.55) 100%
    );
    z-index: 0;
}

#bookCarousel .carousel-content {
    position: relative;
    z-index: 1;
    min-height: 190px;
    display: flex;
    align-items: center;
    color: #fffaf5;
    text-shadow: 0 2px 12px rgba(0, 0, 0, 0.35);
    padding: 0.85rem 0;
}

@media (min-width: 576px) {
    #bookCarousel .carousel-content {
        min-height: 260px;
        padding: 1.25rem 0;
    }
}

@media (min-width: 768px) {
    #bookCarousel .carousel-content {
        min-height: 340px;
        padding: 1.5rem 0;
    }
}

@media (min-width: 992px) {
    #bookCarousel .carousel-content {
        min-height: 380px;
        padding: 1.75rem 0;
    }
}

#bookCarousel .carousel-content h1,
#bookCarousel .carousel-content h2 {
    font-weight: 700;
    letter-spacing: 0.02em;
}

@media (max-width: 575.98px) {
    #bookCarousel .carousel-content h1 {
        font-size: 1.35rem;
    }

    #bookCarousel .carousel-content h2 {
        font-size: 1.15rem;
    }

    #bookCarousel .carousel-content .lead {
        font-size: 0.9rem;
        margin-bottom: 0;
    }
}

#bookCarousel .carousel-content .lead {
    color: rgba(255, 250, 245, 0.95);
}

#bookCarousel .carousel-indicators {
    z-index: 2;
    margin-bottom: 0.5rem;
}

#bookCarousel .carousel-control-prev,
#bookCarousel .carousel-control-next {
    z-index: 2;
}

/* 卡片样式 */
.book-card {
    border: none;
    border-radius: 12px;
    transition: all 0.3s ease;
    background: white;
    overflow: hidden;
    height: 100%;
}

.book-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0,0,0,.1);
}

.book-cover {
    height: 200px;
    background-size: cover;
    background-position: center;
    border-radius: 8px;
}

.featured-books-section .book-cover {
    height: 118px;
    border-radius: 0;
}

@media (min-width: 400px) {
    .featured-books-section .book-cover {
        height: 135px;
    }
}

@media (min-width: 576px) {
    .featured-books-section .book-cover {
        height: 155px;
    }
}

@media (min-width: 768px) {
    .featured-books-section .book-cover {
        height: 200px;
        border-radius: 8px;
    }
}

.featured-books-section .card-body {
    padding: 0.55rem 0.6rem;
}

@media (min-width: 768px) {
    .featured-books-section .card-body {
        padding: 1rem;
    }
}

.featured-books-section .card-title {
    font-size: 0.82rem;
    line-height: 1.25;
    margin-bottom: 0.35rem;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

@media (min-width: 768px) {
    .featured-books-section .card-title {
        font-size: 1.1rem;
        margin-bottom: 0.5rem;
        -webkit-line-clamp: 3;
    }
}

.featured-books-section .card-text {
    font-size: 0.72rem;
    line-height: 1.3;
    margin-bottom: 0.25rem;
}

@media (min-width: 768px) {
    .featured-books-section .card-text {
        font-size: 0.875rem;
        margin-bottom: 0.5rem;
    }
}

.featured-books-section .badge {
    font-size: 0.65rem;
    padding: 0.2em 0.45em;
}

@media (min-width: 768px) {
    .featured-books-section .badge {
        font-size: 0.75rem;
        padding: 0.35em 0.65em;
    }
}

.search-book-header .category-title {
    margin-bottom: 1rem;
}

.category-section {
    padding: 2rem 0;
    background: white;
}

.category-section-tiles {
    padding-top: 1.35rem;
    padding-bottom: 1.35rem;
}

@media (min-width: 768px) {
    .category-section-tiles {
        padding-top: 2rem;
        padding-bottom: 2rem;
    }
}

.category-section-tiles .category-tile {
    border-radius: 0.5rem;
    transition: background-color 0.2s ease, transform 0.2s ease;
}

.category-section-tiles .category-tile:hover {
    background-color: rgba(44, 122, 123, 0.06);
}

.category-section-tiles .category-icon {
    width: 44px;
    height: 44px;
    font-size: 1.15rem;
    margin-bottom: 0.5rem;
}

@media (min-width: 576px) {
    .category-section-tiles .category-icon {
        width: 52px;
        height: 52px;
        font-size: 1.3rem;
    }
}

@media (min-width: 768px) {
    .category-section-tiles .category-icon {
        width: 60px;
        height: 60px;
        font-size: 1.5rem;
        margin-bottom: 1rem;
    }
}

.category-section-tiles .category-tile-title {
    font-size: 0.68rem;
    font-weight: 600;
    line-height: 1.25;
    hyphens: auto;
    word-break: break-word;
}

@media (min-width: 400px) {
    .category-section-tiles .category-tile-title {
        font-size: 0.78rem;
    }
}

@media (min-width: 576px) {
    .category-section-tiles .category-tile-title {
        font-size: 0.9rem;
    }
}

@media (min-width: 768px) {
    .category-section-tiles .category-tile-title {
        font-size: 1.1rem;
        line-height: 1.3;
    }
}

.category-title {
    font-size: 1.8rem;
    font-weight: bold;
    color: var(--primary-color);
    margin-bottom: 2rem;
}

.category-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.footer {
    background: #2d3748;
    color: white;
    padding: 3rem 0 1rem;
    margin-top: 4rem;
}

@media (max-width: 767.98px) {
    .footer {
        margin-top: 2rem;
    }
}

.read-chapter-nav .btn {
    line-height: 1.2;
}

@media (max-width: 575.98px) {
    .read-chapter-nav .btn {
        font-size: 0.8rem;
        padding: 0.25rem 0.5rem;
    }
}

.footer a {
    color: #cbd5e0;
    text-decoration: none;
}

.footer a:hover {
    color: white;
}

/* 搜索框样式 */
.search-box {
    position: relative;
    max-width: 500px;
    margin: 0 auto;
}

.search-input {
    border-radius: 25px;
    border: 2px solid var(--primary-color);
    padding: 10px 20px;
    width: 100%;
}

.search-btn {
    position: absolute;
    right: 5px;
    top: 50%;
    transform: translateY(-50%);
    background: var(--primary-color);
    border: none;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.book-detail-cover-img {
    display: block;
    width: 100%;
    max-width: 220px;
    height: auto;
    aspect-ratio: 2 / 3;
    object-fit: cover;
    margin-left: auto;
    margin-right: auto;
}

@media (min-width: 768px) {
    .book-detail-cover-img {
        max-width: 100%;
        margin-left: 0;
        margin-right: 0;
    }
}

.book-detail-cover-placeholder {
    width: 100%;
    max-width: 220px;
    aspect-ratio: 2 / 3;
    margin-left: auto;
    margin-right: auto;
    background: linear-gradient(145deg, #e2e8f0 0%, #cbd5e0 50%, #a0aec0 100%);
}

@media (min-width: 768px) {
    .book-detail-cover-placeholder {
        max-width: 100%;
        margin-left: 0;
        margin-right: 0;
    }
}

.chapter-mini-card {
    position: relative;
    padding: 0.85rem 1rem;
    background: #fff;
    border: 1px solid rgba(44, 122, 123, 0.12);
    border-radius: 0.85rem;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
    transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
    overflow: hidden;
}

.chapter-mini-card:hover {
    border-color: rgba(44, 122, 123, 0.28);
    box-shadow: 0 6px 16px rgba(44, 122, 123, 0.1);
    transform: translateY(-1px);
}

.chapter-mini-badge {
    font-size: 0.65rem;
    font-weight: 600;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    color: var(--primary-color);
    background: rgba(44, 122, 123, 0.1);
    padding: 0.25rem 0.55rem;
    border-radius: 999px;
}

.chapter-mini-title {
    font-size: 0.8rem;
    font-weight: 500;
    line-height: 1.4;
    color: var(--text-dark);
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

@media (min-width: 768px) {
    .chapter-mini-title {
        font-size: 0.85rem;
    }
}

/* Reading-friendly typography */
.reading-content p {
    margin-bottom: 1.5em;
    text-align: justify;
}

.reading-content h3 {
    margin-top: 2em;
    margin-bottom: 1em;
    font-weight: 600;
}

.reading-content .dialogue {
    background-color: #f8f9fa;
    padding: 1em 1.5em;
    border-left: 4px solid var(--primary-color);
    margin: 1.5em 0;
    font-style: italic;
}

/* Chapter navigation active state */
.list-group-item.active {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}