/* ============================================
   户外背包 - 案例展示风格样式
   主色调: #00bcd4 (青色)
   ============================================ */

/* CSS 变量定义 */
:root {
  --accent-color: #00bcd4;
  --accent-dark: #0097a7;
  --text-primary: #333;
  --text-secondary: #666;
  --text-light: #999;
  --bg-white: #fff;
  --bg-light: #f5f5f5;
  --bg-dark: #263238;
  --border-color: #e0e0e0;
  --shadow: 0 2px 8px rgba(0,0,0,0.1);
  --shadow-hover: 0 4px 16px rgba(0,0,0,0.15);
  --radius: 8px;
  --transition: all 0.3s ease;
}

/* 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;
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-light);
}

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

ul {
  list-style: none;
}

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

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

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

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

.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-color);
  border-bottom-color: var(--accent-color);
}

/* ============================================
   分屏布局 Split Screen
   ============================================ */
.split-section {
  display: grid;
  grid-template-columns: 1fr 1fr;
  min-height: 500px;
}

.split-left,
.split-right {
  padding: 60px 40px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.split-left {
  background: var(--bg-white);
}

.split-right {
  background: var(--accent-color);
  color: var(--bg-white);
}

.split-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 20px;
  line-height: 1.3;
}

.split-right .split-title {
  color: var(--bg-white);
}

.split-desc {
  font-size: 1.1rem;
  line-height: 1.8;
  margin-bottom: 30px;
  color: var(--text-secondary);
}

.split-right .split-desc {
  color: rgba(255,255,255,0.9);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius);
  cursor: pointer;
  transition: var(--transition);
  border: none;
}

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

.btn-primary:hover {
  background: var(--accent-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}

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

.btn-white:hover {
  background: var(--bg-light);
  transform: translateY(-2px);
}

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

.breadcrumb-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  font-size: 0.9rem;
  color: var(--text-light);
}

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

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

.breadcrumb span {
  margin: 0 8px;
  color: var(--text-light);
}

.breadcrumb strong {
  color: var(--text-primary);
  font-weight: 500;
}

/* ============================================
   内容区域 Main Content
   ============================================ */
.main-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 20px;
}

.section-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 24px;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 12px;
}

.section-title::before {
  content: '';
  width: 4px;
  height: 24px;
  background: var(--accent-color);
  border-radius: 2px;
}

/* ============================================
   三栏文章列表
   ============================================ */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 40px;
}

.article-column {
  background: var(--bg-white);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
}

.column-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--accent-color);
  color: var(--text-primary);
}

.article-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.article-item {
  padding: 12px 0;
  border-bottom: 1px solid var(--border-color);
}

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

.article-item a {
  display: block;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.5;
}

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

.article-item .date {
  font-size: 0.8rem;
  color: var(--text-light);
  margin-top: 4px;
}

/* ============================================
   分类页样式
   ============================================ */
.category-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 30px;
  margin-bottom: 40px;
}

.category-card {
  background: var(--bg-white);
  border-radius: var(--radius);
  padding: 30px;
  box-shadow: var(--shadow);
  transition: var(--transition);
}

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

.category-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 20px;
}

.category-icon {
  width: 56px;
  height: 56px;
  background: var(--accent-color);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--bg-white);
  font-size: 1.5rem;
}

.category-name {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
}

.category-items {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 20px;
}

.category-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px;
  background: var(--bg-light);
  border-radius: var(--radius);
  transition: var(--transition);
}

.category-item:hover {
  background: var(--accent-color);
}

.category-item:hover .item-title,
.category-item:hover .item-desc {
  color: var(--bg-white);
}

.item-info {
  flex: 1;
}

.item-title {
  font-weight: 500;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.item-desc {
  font-size: 0.85rem;
  color: var(--text-light);
}

/* ============================================
   文章详情页
   ============================================ */
.article-detail {
  background: var(--bg-white);
  border-radius: var(--radius);
  padding: 40px;
  box-shadow: var(--shadow);
  margin-bottom: 40px;
}

.article-header {
  margin-bottom: 30px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border-color);
}

.article-title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 16px;
  line-height: 1.4;
}

.article-meta {
  display: flex;
  gap: 20px;
  color: var(--text-light);
  font-size: 0.9rem;
}

.article-meta span {
  display: flex;
  align-items: center;
  gap: 6px;
}

.article-body {
  font-size: 1.05rem;
  line-height: 1.9;
  color: var(--text-secondary);
}

.article-body h2 {
  font-size: 1.5rem;
  color: var(--text-primary);
  margin: 32px 0 16px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--border-color);
}

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

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

.article-body ul,
.article-body ol {
  margin-bottom: 16px;
  padding-left: 24px;
}

.article-body ul li {
  list-style: disc;
  margin-bottom: 8px;
}

.article-body ol li {
  list-style: decimal;
  margin-bottom: 8px;
}

.article-body strong {
  color: var(--text-primary);
}

/* 版本对比 */
.version-compare {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 30px;
  margin: 30px 0;
}

.version-box {
  background: var(--bg-light);
  border-radius: var(--radius);
  padding: 24px;
  border-left: 4px solid var(--accent-color);
}

.version-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--accent-color);
  margin-bottom: 12px;
}

/* ============================================
   推荐文章区域
   ============================================ */
.recommended-section {
  background: var(--bg-white);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
  margin-bottom: 24px;
}

.recommended-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.tag {
  display: inline-block;
  padding: 8px 16px;
  background: var(--bg-light);
  border-radius: 20px;
  font-size: 0.9rem;
  color: var(--text-secondary);
  transition: var(--transition);
}

.tag:hover {
  background: var(--accent-color);
  color: var(--bg-white);
}

/* 双栏布局 */
.two-column {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

/* ============================================
   404 页面
   ============================================ */
.error-page {
  min-height: 500px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 60px 20px;
}

.error-code {
  font-size: 8rem;
  font-weight: 700;
  color: var(--accent-color);
  line-height: 1;
  margin-bottom: 20px;
  opacity: 0.8;
}

.error-title {
  font-size: 1.75rem;
  color: var(--text-primary);
  margin-bottom: 16px;
}

.error-desc {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 32px;
  max-width: 400px;
}

/* ============================================
   页脚 Footer
   ============================================ */
.footer {
  background: var(--bg-dark);
  color: var(--bg-white);
  padding: 40px 0;
  margin-top: 60px;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  text-align: center;
}

.footer-logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent-color);
  margin-bottom: 16px;
}

.footer-desc {
  color: rgba(255,255,255,0.6);
  margin-bottom: 24px;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin-bottom: 24px;
}

.footer-links a {
  color: rgba(255,255,255,0.8);
}

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

.footer-copy {
  color: rgba(255,255,255,0.4);
  font-size: 0.9rem;
}

/* ============================================
   响应式设计
   ============================================ */
@media (max-width: 768px) {
  .header-inner {
    flex-direction: column;
    height: auto;
    padding: 16px 20px;
    gap: 12px;
  }

  .nav {
    gap: 20px;
    flex-wrap: wrap;
    justify-content: center;
  }

  .split-section {
    grid-template-columns: 1fr;
  }

  .split-left,
  .split-right {
    padding: 40px 24px;
  }

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

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

  .two-column {
    grid-template-columns: 1fr;
  }

  .version-compare {
    grid-template-columns: 1fr;
  }

  .article-detail {
    padding: 24px;
  }

  .article-title {
    font-size: 1.5rem;
  }

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

@media (max-width: 480px) {
  .split-title {
    font-size: 1.5rem;
  }

  .section-title {
    font-size: 1.25rem;
  }

  .btn {
    padding: 12px 24px;
    font-size: 0.9rem;
  }
}