/* ===== 基础重置 ===== */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --accent-color: #607d8b;
  --accent-dark: #455a64;
  --accent-light: #90a4ae;
  --text-primary: #333;
  --text-secondary: #666;
  --text-muted: #999;
  --bg-primary: #fff;
  --bg-secondary: #f5f7f8;
  --bg-tertiary: #eceff1;
  --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: 6px;
  --max-width: 1200px;
  --header-height: 64px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-secondary);
}

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

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

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

/* ===== 布局容器 ===== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* ===== 页头 ===== */
.header {
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  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: 20px;
  font-weight: 700;
  color: var(--accent-color);
}

.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-color);
  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;
  width: 180px;
  font-size: 14px;
}

.search-box button {
  border: none;
  background: none;
  cursor: pointer;
  color: var(--text-muted);
}

/* ===== 面包屑 ===== */
.breadcrumb {
  background: var(--bg-tertiary);
  padding: 12px 0;
  font-size: 13px;
  color: var(--text-secondary);
}

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

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

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

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

.hero h1 {
  font-size: 36px;
  font-weight: 700;
  margin-bottom: 16px;
}

.hero p {
  font-size: 16px;
  opacity: 0.9;
  max-width: 600px;
  margin: 0 auto;
}

/* ===== 页面标题 ===== */
.page-header {
  background: var(--bg-primary);
  padding: 40px 0;
  border-bottom: 1px solid var(--border-color);
}

.page-header h1 {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 8px;
}

.page-header p {
  color: var(--text-secondary);
}

/* ===== 卡片组件 ===== */
.card {
  background: var(--bg-primary);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
  transition: box-shadow 0.2s;
}

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

.card-body {
  padding: 20px;
}

.card-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
}

.card-text {
  color: var(--text-secondary);
  font-size: 13px;
  line-height: 1.6;
}

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

/* ===== 规格表格 ===== */
.spec-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--bg-primary);
  border-radius: var(--radius);
  overflow: hidden;
}

.spec-table th,
.spec-table td {
  padding: 14px 20px;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

.spec-table th {
  background: var(--bg-tertiary);
  font-weight: 600;
  font-size: 13px;
  color: var(--text-secondary);
  text-transform: uppercase;
}

.spec-table tr:last-child td {
  border-bottom: none;
}

.spec-table td:first-child {
  font-weight: 500;
  color: var(--text-secondary);
  width: 200px;
}

/* ===== 规格列表 ===== */
.spec-list {
  background: var(--bg-primary);
  border-radius: var(--radius);
  overflow: hidden;
}

.spec-group {
  border-bottom: 1px solid var(--border-color);
}

.spec-group:last-child {
  border-bottom: none;
}

.spec-group-title {
  background: var(--bg-tertiary);
  padding: 14px 20px;
  font-weight: 600;
  font-size: 14px;
}

.spec-item {
  display: flex;
  padding: 12px 20px;
  border-bottom: 1px solid var(--border-color);
}

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

.spec-label {
  width: 180px;
  color: var(--text-secondary);
  font-size: 13px;
}

.spec-value {
  flex: 1;
  font-weight: 500;
}

/* ===== 按钮 ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
  border: none;
}

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

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

.btn-outline {
  background: transparent;
  color: var(--accent-color);
  border: 1px solid var(--accent-color);
}

.btn-outline:hover {
  background: var(--accent-color);
  color: #fff;
}

.btn-sm {
  padding: 6px 14px;
  font-size: 13px;
}

/* ===== 网格布局 ===== */
.grid {
  display: grid;
  gap: 20px;
}

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

.grid-4 {
  grid-template-columns: repeat(4, 1fr);
}

/* ===== 文章列表 ===== */
.article-list {
  display: flex;
  flex-direction: column;
  gap: 1px;
  background: var(--border-color);
  border-radius: var(--radius);
  overflow: hidden;
}

.article-item {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 16px 20px;
  background: var(--bg-primary);
  transition: background 0.2s;
}

.article-item:hover {
  background: var(--bg-secondary);
}

.article-num {
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-tertiary);
  border-radius: var(--radius);
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
}

.article-num.hot {
  background: var(--accent-color);
  color: #fff;
}

.article-info {
  flex: 1;
}

.article-title {
  font-weight: 500;
  margin-bottom: 4px;
}

.article-meta {
  font-size: 12px;
  color: var(--text-muted);
}

/* ===== 内容区域 ===== */
.section {
  padding: 40px 0;
}

.section-title {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.section-title::before {
  content: '';
  width: 4px;
  height: 20px;
  background: var(--accent-color);
  border-radius: 2px;
}

/* ===== 文章内容 ===== */
.article-content {
  background: var(--bg-primary);
  border-radius: var(--radius);
  padding: 40px;
  box-shadow: var(--shadow);
}

.article-header {
  margin-bottom: 32px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border-color);
}

.article-header h1 {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 12px;
  line-height: 1.4;
}

.article-body {
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-primary);
}

.article-body h2 {
  font-size: 20px;
  font-weight: 600;
  margin: 32px 0 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
}

.article-body h3 {
  font-size: 17px;
  font-weight: 600;
  margin: 24px 0 12px;
}

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

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

.article-body li {
  margin-bottom: 8px;
}

.article-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 20px 0;
  font-size: 14px;
}

.article-body th,
.article-body td {
  padding: 12px 16px;
  border: 1px solid var(--border-color);
  text-align: left;
}

.article-body th {
  background: var(--bg-tertiary);
  font-weight: 600;
}

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

.pagination a,
.pagination span {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 36px;
  height: 36px;
  padding: 0 12px;
  border-radius: var(--radius);
  font-size: 14px;
  background: var(--bg-primary);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
}

.pagination a:hover {
  background: var(--accent-color);
  color: #fff;
  border-color: var(--accent-color);
}

.pagination .current {
  background: var(--accent-color);
  color: #fff;
  border-color: var(--accent-color);
}

/* ===== 三栏底部 ===== */
.footer-content {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px;
  margin-bottom: 32px;
}

.footer-column h4 {
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.footer-column ul {
  list-style: none;
}

.footer-column li {
  margin-bottom: 10px;
}

.footer-column a {
  color: var(--text-secondary);
  font-size: 13px;
}

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

/* ===== 页脚 ===== */
.footer {
  background: var(--bg-primary);
  border-top: 1px solid var(--border-color);
  padding: 40px 0 24px;
  margin-top: 40px;
}

.footer-bottom {
  text-align: center;
  padding-top: 24px;
  border-top: 1px solid var(--border-color);
  color: var(--text-muted);
  font-size: 13px;
}

/* ===== 404页面 ===== */
.error-page {
  text-align: center;
  padding: 80px 20px;
}

.error-code {
  font-size: 120px;
  font-weight: 700;
  color: var(--accent-color);
  line-height: 1;
  margin-bottom: 16px;
}

.error-title {
  font-size: 24px;
  font-weight: 600;
  margin-bottom: 12px;
}

.error-desc {
  color: var(--text-secondary);
  margin-bottom: 32px;
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .grid-4 {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 768px) {
  .nav {
    display: none;
  }

  .search-box {
    display: none;
  }

  .grid-3,
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-content {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .hero h1 {
    font-size: 28px;
  }

  .article-content {
    padding: 24px;
  }

  .spec-item {
    flex-direction: column;
    gap: 4px;
  }

  .spec-label {
    width: auto;
  }

  .spec-table {
    display: block;
    overflow-x: auto;
  }
}

@media (max-width: 480px) {
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }

  .hero {
    padding: 40px 0;
  }

  .hero h1 {
    font-size: 24px;
  }
}