/*
Theme Name: 图书展示与下载
Theme URI:  https://example.com/book-showcase
Author:     Book Showcase Team
Description: 专为图书展示与下载设计的 WordPress 主题，使用普通文章类型管理图书，内置 JSON-LD 结构化标记、Open Graph 标签和 SEO Meta 支持。
Version:    1.0.0
License:    GPL-2.0-or-later
License URI: https://www.gnu.org/licenses/gpl-2.0.html
Text Domain: book-showcase
Language:   zh-CN
*/

/* =Variables
-------------------------------------------------------------- */
:root {
    --color-primary: #5c9ead;
    --color-primary-dark: #4a8a98;
    --color-primary-light: #7eb8c9;
    --color-accent: #e8a87c;
    --color-accent-dark: #d4956a;
    --color-text: #4a4a4a;
    --color-text-light: #8a8a8a;
    --color-bg: #f8f9fa;
    --color-bg-alt: #fefefe;
    --color-white: #ffffff;
    --color-border: #e5e9ec;
    --color-hover: #f0f4f5;
    --spacing-md: 20px;
    --spacing-lg: 30px;
    --spacing-xl: 40px;
    --border-radius: 16px;
    --shadow: 0 4px 20px rgba(92, 158, 173, 0.12);
    --shadow-hover: 0 8px 30px rgba(92, 158, 173, 0.2);
}

/* =Reset
-------------------------------------------------------------- */
*, *::before, *::after {
    box-sizing: border-box;
}

html {
    font-size: 16px;
}

body {
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    color: var(--color-text);
    background-color: var(--color-bg);
    line-height: 1.6;
}

a {
    color: var(--color-primary);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

img {
    max-width: 100%;
    height: auto;
}

/* =Layout
-------------------------------------------------------------- */
.site {
    max-width: 1200px;
    margin: 0 auto;
    background: var(--color-white);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

/* =Header
-------------------------------------------------------------- */
.site-header {
    background: var(--color-white);
    border-bottom: 1px solid var(--color-border);
    padding: var(--spacing-md) 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.03);
}

.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.header-left {
    flex: 1;
    display: flex;
    align-items: center;
    gap: 12px;
}

.site-header-text {
    display: flex;
    flex-direction: column;
    gap: 2px;
    text-align: left;
}

.site-logo {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    border-radius: 10px;
    color: var(--color-white);
    flex-shrink: 0;
    overflow: hidden;
}

.site-logo img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.site-title {
    margin: 0;
    font-size: 1.5rem;
}

.site-title a {
    color: var(--color-text);
}

.site-title a:hover {
    text-decoration: none;
}

.site-description {
    margin: 0;
    color: var(--color-text-light);
    font-size: 0.875rem;
}

/* 搜索框样式 */
.header-search {
    flex-shrink: 0;
}

.header-search form {
    display: flex;
    align-items: center;
}

.search-input {
    width: 240px;
    height: 42px;
    padding: 10px 16px;
    border: 2px solid var(--color-border);
    border-right: none;
    border-radius: 21px 0 0 21px;
    font-size: 0.95rem;
    outline: none;
    transition: border-color 0.3s ease;
}

.search-input:focus {
    border-color: var(--color-primary);
}

.search-input::placeholder {
    color: var(--color-text-light);
}

.search-btn {
    width: 48px;
    height: 42px;
    background: var(--color-primary);
    border: 2px solid var(--color-primary);
    border-left: none;
    border-radius: 0 21px 21px 0;
    color: var(--color-white);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.3s ease;
}

.search-btn:hover {
    background: var(--color-primary-dark);
    border-color: var(--color-primary-dark);
}

@media (max-width: 768px) {
    .site-header .container {
        flex-direction: column;
        align-items: stretch;
        gap: 15px;
    }

    .header-left {
        text-align: center;
    }

    .header-search {
        width: 100%;
    }

    .header-search form {
        justify-content: center;
    }

    .search-input {
        width: 160px;
    }

    .search-btn {
        width: 42px;
    }
}

/* =Navigation
-------------------------------------------------------------- */
.main-navigation {
    background: var(--color-white);
    border-bottom: 1px solid var(--color-border);
    position: relative;
}

.main-navigation .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.main-navigation ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    flex-wrap: wrap;
}

.main-navigation li {
    position: relative;
}

.main-navigation a {
    display: block;
    padding: 15px 20px;
    color: var(--color-text);
    transition: all 0.3s ease;
}

.main-navigation a:hover {
    background: var(--color-primary);
    color: var(--color-white);
    text-decoration: none;
}

/* Mobile Menu Toggle */
.menu-toggle {
    display: none;
    align-items: center;
    gap: 8px;
    padding: 10px 18px;
    background: var(--color-primary);
    border: none;
    border-radius: var(--border-radius);
    color: var(--color-white);
    cursor: pointer;
    font-size: 0.95rem;
    font-weight: 500;
    transition: all 0.3s ease;
}

.menu-toggle:hover {
    background: var(--color-primary-dark);
    transform: scale(1.02);
}

.menu-toggle .menu-icon {
    font-size: 1.2rem;
}

.menu-toggle .menu-text {
    font-family: inherit;
}

.main-navigation .sub-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background: var(--color-white);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    min-width: 220px;
    box-shadow: var(--shadow);
    z-index: 100;
}

.main-navigation li:hover > .sub-menu {
    display: block;
}

.main-navigation .sub-menu a {
    padding: 12px 20px;
    border-bottom: 1px solid var(--color-border);
}

.main-navigation .sub-menu li:last-child a {
    border-bottom: none;
}

/* =Content
-------------------------------------------------------------- */
.site-content {
    padding: var(--spacing-md) 15px;
}

.entry-title {
    margin: 0 0 15px;
    font-size: 2rem;
    line-height: 1.3;
}

.entry-title a {
    color: var(--color-text);
}

.entry-meta {
    color: var(--color-text-light);
    font-size: 0.875rem;
    margin-bottom: 20px;
}

.entry-content {
    line-height: 1.8;
    padding-right: 10px;
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--color-border);
}

.entry-footer {
    margin-top: 20px;
    padding-top: 15px;
    border-top: 1px solid var(--color-border);
}

.entry-footer-cats {
    margin-top: 15px;
    padding: 12px 10px;
    background: var(--color-bg);
    border-radius: var(--border-radius);
}

.entry-footer-cats .cat-links,
.entry-footer-cats .tags-links {
    display: inline-block;
    margin-right: 15px;
    color: var(--color-text-light);
    font-size: 0.875rem;
}

.entry-footer-cats .cat-links a,
.entry-footer-cats .tags-links a {
    display: inline-block;
    padding: 4px 12px;
    margin: 2px;
    background: var(--color-white);
    border: 1px solid var(--color-border);
    border-radius: 20px;
    color: var(--color-text);
    font-size: 0.8rem;
    transition: all 0.3s ease;
}

.entry-footer-cats .cat-links a:hover,
.entry-footer-cats .tags-links a:hover {
    background: var(--color-primary);
    border-color: var(--color-primary);
    color: var(--color-white);
    text-decoration: none;
}

/* =Book Grid (Homepage)
-------------------------------------------------------------- */
.book-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 20px;
    margin: 0;
    padding: 0;
    list-style: none;
}

.book-card {
    background: var(--color-white);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    overflow: hidden;
    transition: all 0.3s ease;
}

.book-card:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-4px);
}

.book-card-cover {
    width: 100%;
    height: 200px;
    object-fit: contain;
    background: linear-gradient(160deg, #f0f7f9 0%, #e8f1f3 100%);
}

.book-card-cover-placeholder {
    width: 100%;
    height: 200px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: linear-gradient(160deg, #f0f7f9 0%, #e8f1f3 100%);
    color: var(--color-primary);
    font-size: 0.75rem;
}

.book-card-cover-placeholder svg {
    margin-bottom: 8px;
    width: 40px;
    height: 40px;
    color: var(--color-primary-light);
}

.book-card-content {
    padding: 12px;
}

.book-card-title {
    margin: 0 0 6px;
    font-size: 0.9rem;
    font-weight: 600;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.book-card-title a {
    color: var(--color-text);
}

.book-card-excerpt {
    color: var(--color-text-light);
    font-size: 0.75rem;
    margin: 0;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* =Book Single
-------------------------------------------------------------- */
.book-detail {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: var(--spacing-md);
    padding: var(--spacing-md) 10px;
}

.book-detail-info {
    padding: 0 10px;
}

.book-detail-info h1 {
    margin: 0 0 20px;
    font-size: 2rem;
    padding-right: 10px;
}

/* 详情页封面容器 - 固定尺寸确保统一 */
.book-cover {
    width: 100%;
    max-width: 280px;
}

.book-cover .book-card-cover {
    width: 100%;
    height: 380px;
    object-fit: contain;
    background: linear-gradient(160deg, #f0f7f9 0%, #e8f1f3 100%);
    border-radius: var(--border-radius);
    padding: 10px;
    box-shadow: var(--shadow);
}

.book-cover .book-card-cover-placeholder {
    width: 100%;
    height: 380px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: linear-gradient(160deg, #f0f7f9 0%, #e8f1f3 100%);
    border-radius: var(--border-radius);
    color: var(--color-primary);
    box-shadow: var(--shadow);
}

.book-detail-info h1 {
    margin: 0 0 20px;
    font-size: 2rem;
}

.book-meta-list {
    list-style: none;
    margin: 0 0 30px;
    padding: 0;
}

.book-meta-list li {
    padding: 12px 0;
    border-bottom: 1px solid var(--color-border);
    display: flex;
}

.book-meta-label {
    font-weight: 600;
    color: var(--color-text-light);
    min-width: 100px;
}

/* =Download Button
-------------------------------------------------------------- */
.book-download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 14px 32px;
    margin: 5px auto;
    background: var(--color-primary);
    color: #fff;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    transition: all 0.25s ease;
    box-shadow: 0 2px 8px rgba(26, 115, 232, 0.25);
    border: none;
}

.book-download-btn:hover {
    background: var(--color-primary-dark);
    text-decoration: none;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(26, 115, 232, 0.35);
}

.book-download-btn:active {
    transform: translateY(0);
    box-shadow: 0 1px 4px rgba(26, 115, 232, 0.2);
}

.book-download-btn svg {
    flex-shrink: 0;
}

/* 返回顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    padding: 10px 16px;
    background: var(--color-primary);
    border: none;
    border-radius: 8px;
    color: var(--color-white);
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    box-shadow: var(--shadow);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all 0.3s ease;
    z-index: 999;
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: var(--color-primary-dark);
    transform: translateY(-3px);
    box-shadow: var(--shadow-hover);
}

/* 详情页底部导航 */
.book-nav-links {
    margin-top: 40px;
    padding-top: 30px;
    border-top: 1px solid var(--color-border);
    text-align: center;
}

.back-home {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: 50px;
    color: var(--color-text);
    transition: all 0.3s ease;
}

.back-home:hover {
    background: var(--color-primary);
    border-color: var(--color-primary);
    color: var(--color-white);
    text-decoration: none;
    transform: translateY(-2px);
}

/* =Footer
-------------------------------------------------------------- */
.site-footer {
    background: var(--color-bg);
    color: var(--color-text);
    padding: var(--spacing-lg) 0;
    text-align: center;
    border-top: 1px solid var(--color-border);
}

.site-footer a {
    color: var(--color-primary);
}

.site-footer a:hover {
    color: var(--color-primary-dark);
}

.site-disclaimer {
    margin: 1px 0 0;
    padding: 8px 12px;
    background: rgba(232, 168, 124, 0.15);
    border-radius: 4px;
    font-size: 0.85rem;
    color: var(--color-text-light);
    display: inline-block;
}

/* =Sidebar
-------------------------------------------------------------- */
.widget {
    margin-bottom: 30px;
    padding: var(--spacing-md);
    background: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
}

.widget-title {
    margin: 0 0 15px;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--color-text);
}

.widget ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.widget li {
    padding: 8px 0;
    border-bottom: 1px solid var(--color-border);
    transition: color 0.3s ease;
}

.widget li:hover {
    color: var(--color-primary);
}

/* =404 & Search
-------------------------------------------------------------- */
.not-found,
.no-results {
    text-align: center;
    padding: 60px 20px;
}

.not-found h1,
.no-results h1 {
    font-size: 4rem;
    font-weight: 300;
    color: var(--color-primary-light);
    margin: 0 0 20px;
}

.not-found p,
.no-results p {
    color: var(--color-text-light);
    font-size: 1.125rem;
}

.search-form {
    display: flex;
    max-width: 500px;
    margin: 30px auto;
}

.search-form input[type="search"] {
    flex: 1;
    padding: 12px;
    border: 2px solid var(--color-border);
    border-radius: var(--border-radius) 0 0 var(--border-radius);
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.search-form input[type="search"]:focus {
    outline: none;
    border-color: var(--color-primary);
}

.search-form button {
    padding: 12px 24px;
    background: var(--color-primary);
    color: var(--color-white);
    border: none;
    border-radius: 0 var(--border-radius) var(--border-radius) 0;
    cursor: pointer;
    transition: all 0.3s ease;
}

.search-form button:hover {
    background: var(--color-accent);
}

/* =Pagination
-------------------------------------------------------------- */
.pagination,
.post-navigation {
    margin-top: var(--spacing-xl);
    text-align: center;
}

.pagination .page-numbers {
    display: inline-block;
    padding: 10px 18px;
    background: var(--color-white);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    margin: 0 4px;
    transition: all 0.3s ease;
}

.pagination .page-numbers:hover {
    background: var(--color-primary-light);
    color: var(--color-white);
    border-color: var(--color-primary-light);
}

.pagination .page-numbers.current {
    background: var(--color-primary);
    color: var(--color-white);
    border-color: var(--color-primary);
}

/* =Responsive
-------------------------------------------------------------- */
@media (max-width: 1200px) {
    .book-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

@media (max-width: 992px) {
    .book-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 768px) {
    .book-detail {
        grid-template-columns: 1fr;
    }

    .book-cover {
        max-width: 220px;
        margin: 0 auto;
    }

    .book-cover .book-card-cover,
    .book-cover .book-card-cover-placeholder {
        height: 300px;
    }

    .book-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 15px;
    }

    /* 列表页封面高度 */
    .book-card-cover,
    .book-card-cover-placeholder {
        height: 180px;
    }

    /* Mobile Navigation */
    .main-navigation .container {
        flex-wrap: wrap;
        padding: 10px 20px;
    }

    .menu-toggle {
        display: flex;
    }

    .main-navigation ul {
        display: none;
        width: 100%;
        flex-direction: column;
        padding: 10px 0;
        border-top: 1px solid var(--color-border);
    }

    .main-navigation ul.toggled {
        display: flex;
    }

    .main-navigation li {
        width: 100%;
    }

    .main-navigation a {
        padding: 14px 20px;
        border-bottom: 1px solid var(--color-border);
        background: var(--color-white);
    }

    .main-navigation a:hover {
        background: var(--color-primary);
        color: var(--color-white);
    }

    /* 子菜单在移动端 */
    .main-navigation .sub-menu {
        position: static;
        box-shadow: none;
        border: none;
        border-radius: 0;
        background: var(--color-bg);
        display: none;
    }

    .main-navigation li:hover > .sub-menu,
    .main-navigation .sub-menu.toggled {
        display: block;
    }

    .main-navigation .sub-menu a {
        padding-left: 40px;
        background: var(--color-bg);
    }

    .site-header .container {
        flex-direction: column;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 10px;
    }

    .book-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
    }

    .book-download-btn {
        display: block;
        text-align: center;
    }

    .not-found h1,
    .no-results h1 {
        font-size: 3rem;
    }

    .menu-toggle {
        width: 100%;
        justify-content: center;
    }

    /* 小屏幕封面高度 */
    .book-card-cover,
    .book-card-cover-placeholder {
        height: 160px;
    }
}

/* =Utilities
-------------------------------------------------------------- */
.clearfix::after {
    content: "";
    display: table;
    clear: both;
}

.screen-reader-text {
    border: 0;
    clip: rect(1px, 1px, 1px, 1px);
    clip-path: inset(50%);
    height: 1px;
    margin: -1px;
    overflow: hidden;
    padding: 0;
    position: absolute;
    width: 1px;
    word-wrap: normal !important;
}

.screen-reader-text:focus {
    background-color: #f1f1f1;
    border-radius: 3px;
    box-shadow: 0 0 2px 2px rgba(0, 0, 0, 0.6);
    clip: auto !important;
    clip-path: none;
    color: #21759b;
    display: block;
    font-size: 14px;
    font-weight: 700;
    height: auto;
    left: 5px;
    line-height: normal;
    padding: 15px 23px 14px;
    text-decoration: none;
    top: 5px;
    width: auto;
    z-index: 100000;
}

/* =Page Header (from main.css)
-------------------------------------------------------------- */
.page-header {
    margin-bottom: var(--spacing-lg);
    padding: var(--spacing-md) 0 var(--spacing-md) 20px;
    border-bottom: 1px solid var(--color-border);
    border-left: 4px solid var(--color-primary);
}

.page-title {
    margin: 0;
    font-size: 2rem;
}

.archive-description {
    margin-top: var(--spacing-md);
    color: var(--color-text-light);
}

/* =Comments (from main.css)
-------------------------------------------------------------- */
.comments-area {
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--color-border);
}