/* ===== 基础变量 ===== */
:root {
  --accent-color: #8bc34a;
  --accent-dark: #689f38;
  --accent-light: #c5e1a5;
  --text-primary: #333;
  --text-secondary: #666;
  --text-muted: #999;
  --bg-primary: #fff;
  --bg-secondary: #f5f5f5;
  --bg-card: #fafafa;
  --border-color: #e0e0e0;
  --shadow: 0 2px 8px rgba(0,0,0,0.08);
  --shadow-hover: 0 4px 16px rgba(0,0,0,0.12);
  --radius: 8px;
  --radius-sm: 4px;
  --max-width: 1200px;
  --header-height: 64px;
}

/* ===== 重置样式 ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-secondary);
}

a {
  text-decoration: none;
  color: var(--accent-dark);
  transition: color 0.2s;
}

a:hover {
  color: var(--accent-color);
}

ul {
  list-style: none;
}

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

/* ===== 布局容器 ===== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== 页头 ===== */
.header {
  background: var(--bg-primary);
  box-shadow: var(--shadow);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent-dark);
}

.logo span {
  color: var(--text-primary);
}

.nav {
  display: flex;
  gap: 32px;
}

.nav a {
  color: var(--text-secondary);
  font-weight: 500;
  padding: 8px 0;
  border-bottom: 2px solid transparent;
}

.nav a:hover,
.nav a.active {
  color: var(--accent-dark);
  border-bottom-color: var(--accent-color);
}

.search-box {
  display: flex;
  align-items: center;
  background: var(--bg-secondary);
  border-radius: var(--radius);
  padding: 8px 16px;
  gap: 8px;
}

.search-box input {
  border: none;
  background: none;
  outline: none;
  font-size: 14px;
  width: 180px;
}

.search-box button {
  border: none;
  background: var(--accent-color);
  color: white;
  padding: 6px 16px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 14px;
}

.search-box button:hover {
  background: var(--accent-dark);
}

/* ===== 面包屑 ===== */
.breadcrumb {
  background: var(--bg-primary);
  padding: 16px 0;
  border-bottom: 1px solid var(--border-color);
}

.breadcrumb-inner {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  color: var(--text-secondary);
}

.breadcrumb-inner a:hover {
  color: var(--accent-dark);
}

.breadcrumb-inner .current {
  color: var(--text-primary);
}

/* ===== Hero 区域 ===== */
.hero {
  background: linear-gradient(135deg, var(--accent-light) 0%, var(--accent-color) 100%);
  padding: 60px 0;
  text-align: center;
}

.hero-title {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 12px;
}

.hero-desc {
  font-size: 1.125rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

/* ===== 统计卡片 ===== */
.stats-section {
  padding: 40px 0;
  background: var(--bg-primary);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  max-width: 600px;
  margin: 0 auto;
}

.stat-card {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 24px;
  text-align: center;
  border: 1px solid var(--border-color);
}

.stat-number {
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent-dark);
}

.stat-label {
  font-size: 14px;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* ===== 内容区块 ===== */
.section {
  padding: 48px 0;
}

.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
}

.section-title {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-primary);
}

.section-more {
  font-size: 14px;
  color: var(--accent-dark);
}

/* ===== 书籍卡片 ===== */
.book-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.book-card {
  display: flex;
  gap: 20px;
  background: var(--bg-primary);
  border-radius: var(--radius);
  padding: 20px;
  border: 1px solid var(--border-color);
  transition: box-shadow 0.2s;
}

.book-card:hover {
  box-shadow: var(--shadow-hover);
}

.book-cover {
  width: 100px;
  height: 140px;
  background: linear-gradient(135deg, var(--accent-light), var(--accent-color));
  border-radius: var(--radius-sm);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 12px;
}

.book-info {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.book-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.book-author {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 12px;
}

.book-meta {
  display: flex;
  gap: 16px;
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 12px;
}

.book-status {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  padding: 4px 12px;
  border-radius: 20px;
  background: var(--bg-secondary);
  color: var(--text-secondary);
  width: fit-content;
}

.book-status.reading {
  background: var(--accent-light);
  color: var(--accent-dark);
}

.book-status.finished {
  background: #e8f5e9;
  color: #2e7d32;
}

/* ===== 进度条 ===== */
.progress-bar {
  width: 200px;
  height: 6px;
  background: var(--border-color);
  border-radius: 3px;
  overflow: hidden;
  margin-top: 8px;
}

.progress-fill {
  height: 100%;
  background: var(--accent-color);
  border-radius: 3px;
}

.progress-text {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 4px;
}

/* ===== 分类筛选 ===== */
.filter-bar {
  display: flex;
  gap: 12px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.filter-btn {
  padding: 8px 16px;
  border: 1px solid var(--border-color);
  background: var(--bg-primary);
  border-radius: 20px;
  font-size: 14px;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s;
}

.filter-btn:hover,
.filter-btn.active {
  background: var(--accent-color);
  border-color: var(--accent-color);
  color: white;
}

/* ===== 分类标题 ===== */
.category-header {
  text-align: center;
  padding: 40px 0;
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
}

.category-title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.category-count {
  font-size: 14px;
  color: var(--text-secondary);
}

/* ===== 文章网格 ===== */
.article-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.article-card {
  background: var(--bg-primary);
  border-radius: var(--radius);
  padding: 20px;
  border: 1px solid var(--border-color);
}

.article-card h4 {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 12px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--accent-color);
}

.article-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.article-list a {
  font-size: 14px;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 8px;
}

.article-list a::before {
  content: "•";
  color: var(--accent-color);
}

.article-list a:hover {
  color: var(--accent-dark);
}

/* ===== 文章详情页 ===== */
.article-header {
  background: var(--bg-primary);
  padding: 40px 0;
  border-bottom: 1px solid var(--border-color);
}

.article-title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 12px;
  line-height: 1.3;
}

.article-meta {
  display: flex;
  gap: 20px;
  font-size: 14px;
  color: var(--text-secondary);
}

.article-main {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 40px;
  padding: 40px 0;
}

.article-sidebar {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.sidebar-card {
  background: var(--bg-primary);
  border-radius: var(--radius);
  padding: 20px;
  border: 1px solid var(--border-color);
}

.sidebar-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 16px;
}

.detail-item {
  display: flex;
  justify-content: space-between;
  font-size: 14px;
  padding: 8px 0;
  border-bottom: 1px solid var(--border-color);
}

.detail-item:last-child {
  border-bottom: none;
}

.detail-label {
  color: var(--text-secondary);
}

.detail-value {
  color: var(--text-primary);
  font-weight: 500;
}

.rating {
  color: #ffc107;
}

.article-content {
  background: var(--bg-primary);
  border-radius: var(--radius);
  padding: 32px;
  border: 1px solid var(--border-color);
}

.article-body {
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-primary);
}

.article-body p {
  margin-bottom: 16px;
}

.article-body h2 {
  font-size: 1.5rem;
  font-weight: 600;
  margin: 32px 0 16px;
  color: var(--text-primary);
}

.article-body h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin: 24px 0 12px;
  color: var(--text-primary);
}

.notes-box {
  background: var(--bg-secondary);
  border-radius: var(--radius);
  padding: 20px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--text-secondary);
}

.action-btns {
  display: flex;
  gap: 12px;
  margin-top: 24px;
}

.btn {
  padding: 10px 20px;
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  border: none;
  transition: all 0.2s;
}

.btn-primary {
  background: var(--accent-color);
  color: white;
}

.btn-primary:hover {
  background: var(--accent-dark);
}

.btn-secondary {
  background: var(--bg-secondary);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background: var(--border-color);
}

/* ===== 分页 ===== */
.pagination {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-top: 32px;
}

.page-btn {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border-color);
  background: var(--bg-primary);
  border-radius: var(--radius);
  font-size: 14px;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s;
}

.page-btn:hover,
.page-btn.active {
  background: var(--accent-color);
  border-color: var(--accent-color);
  color: white;
}

/* ===== 页脚 ===== */
.footer {
  background: var(--bg-primary);
  border-top: 1px solid var(--border-color);
  padding: 40px 0;
  margin-top: 48px;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--accent-dark);
}

.footer-logo span {
  color: var(--text-primary);
}

.footer-links {
  display: flex;
  gap: 24px;
}

.footer-links a {
  font-size: 14px;
  color: var(--text-secondary);
}

.footer-links a:hover {
  color: var(--accent-dark);
}

.footer-copy {
  font-size: 13px;
  color: var(--text-muted);
}

/* ===== 404 页面 ===== */
.error-page {
  min-height: calc(100vh - var(--header-height) - 200px);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 60px 24px;
}

.error-code {
  font-size: 8rem;
  font-weight: 700;
  color: var(--accent-light);
  line-height: 1;
}

.error-title {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 16px 0 8px;
}

.error-desc {
  font-size: 16px;
  color: var(--text-secondary);
  margin-bottom: 24px;
}

/* ===== 响应式设计 ===== */
@media (max-width: 992px) {
  .article-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .article-main {
    grid-template-columns: 1fr;
  }

  .article-sidebar {
    order: 2;
  }
}

@media (max-width: 768px) {
  .header-inner {
    flex-wrap: wrap;
    height: auto;
    padding: 12px 0;
    gap: 12px;
  }

  .nav {
    order: 3;
    width: 100%;
    justify-content: center;
    gap: 16px;
  }

  .search-box {
    width: 100%;
  }

  .search-box input {
    flex: 1;
    width: auto;
  }

  .hero-title {
    font-size: 1.75rem;
  }

  .stats-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
  }

  .stat-card {
    padding: 16px;
  }

  .stat-number {
    font-size: 1.5rem;
  }

  .book-card {
    flex-direction: column;
    gap: 16px;
  }

  .book-cover {
    width: 80px;
    height: 112px;
  }

  .article-grid {
    grid-template-columns: 1fr;
  }

  .footer-inner {
    flex-direction: column;
    gap: 16px;
    text-align: center;
  }

  .error-code {
    font-size: 5rem;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }

  .section {
    padding: 32px 0;
  }

  .filter-bar {
    gap: 8px;
  }

  .filter-btn {
    padding: 6px 12px;
    font-size: 13px;
  }
}