/* 防水知识库 - 样式表 */
/* www.buloushui.cn - 提供防水问题诊断 材料技术知识 施工维护建议 */

/* ===== CSS 变量 ===== */
:root {
  --accent-color: #ff9800;
  --accent-light: #ffb74d;
  --accent-dark: #f57c00;
  --text-primary: #333;
  --text-secondary: #666;
  --text-muted: #999;
  --bg-primary: #fff;
  --bg-secondary: #f8f9fa;
  --bg-tertiary: #f0f2f5;
  --border-color: #e0e0e0;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 2px 8px rgba(0,0,0,0.1);
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --max-width: 1200px;
  --header-height: 64px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

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-primary);
}

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

a:hover {
  text-decoration: underline;
}

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

/* ===== 布局容器 ===== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 16px;
}

/* ===== 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 {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: var(--accent-color);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 1rem;
}

.nav {
  display: flex;
  gap: 8px;
}

.nav-link {
  padding: 8px 16px;
  color: var(--text-secondary);
  font-size: 0.9375rem;
  border-radius: var(--radius-sm);
  transition: all 0.2s;
}

.nav-link:hover {
  color: var(--accent-dark);
  background: var(--bg-secondary);
  text-decoration: none;
}

.nav-link.active {
  color: var(--accent-dark);
  background: rgba(255,152,0,0.1);
}

/* ===== 搜索框 ===== */
.search-box {
  position: relative;
  max-width: 600px;
  margin: 0 auto;
}

.search-input {
  width: 100%;
  padding: 14px 48px 14px 20px;
  font-size: 1rem;
  border: 2px solid var(--border-color);
  border-radius: var(--radius-lg);
  background: var(--bg-primary);
  transition: border-color 0.2s;
}

.search-input:focus {
  outline: none;
  border-color: var(--accent-color);
}

.search-btn {
  position: absolute;
  right: 8px;
  top: 50%;
  transform: translateY(-50%);
  width: 40px;
  height: 40px;
  background: var(--accent-color);
  border: none;
  border-radius: var(--radius-md);
  color: #fff;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}

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

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

.hero-desc {
  font-size: 1.125rem;
  color: var(--text-secondary);
  margin-bottom: 32px;
}

/* ===== 分类筛选 ===== */
.category-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
  margin-top: 32px;
}

.category-btn {
  padding: 10px 20px;
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-size: 0.9375rem;
  cursor: pointer;
  transition: all 0.2s;
}

.category-btn:hover,
.category-btn.active {
  background: var(--accent-color);
  border-color: var(--accent-color);
  color: #fff;
}

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

.breadcrumb-list {
  display: flex;
  align-items: center;
  gap: 8px;
  list-style: none;
  font-size: 0.875rem;
  color: var(--text-secondary);
}

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

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

.breadcrumb-separator {
  color: var(--text-muted);
}

/* ===== 手风琴 FAQ ===== */
.faq-section {
  padding: 40px 0;
}

.section-title {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 24px;
  color: var(--text-primary);
}

.accordion-list {
  max-width: 800px;
  margin: 0 auto;
}

.accordion-item {
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  margin-bottom: 12px;
  overflow: hidden;
}

.accordion-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 20px;
  cursor: pointer;
  background: var(--bg-primary);
  transition: background 0.2s;
}

.accordion-header:hover {
  background: var(--bg-secondary);
}

.accordion-title {
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-primary);
}

.accordion-icon {
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-color);
  font-size: 1.25rem;
  transition: transform 0.2s;
}

.accordion-item.active .accordion-icon {
  transform: rotate(180deg);
}

.accordion-content {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

.accordion-item.active .accordion-content {
  max-height: 500px;
}

.accordion-body {
  padding: 0 20px 20px;
  color: var(--text-secondary);
  line-height: 1.8;
}

/* ===== 内容卡片 ===== */
.content-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
  margin-bottom: 40px;
}

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

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

.card-title {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.card-desc {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 12px;
}

.card-meta {
  display: flex;
  gap: 16px;
  font-size: 0.8125rem;
  color: var(--text-muted);
}

/* ===== 文章列表 ===== */
.article-list {
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.article-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 20px;
  border-bottom: 1px solid var(--border-color);
  transition: background 0.2s;
}

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

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

.article-icon {
  width: 48px;
  height: 48px;
  background: rgba(255,152,0,0.1);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-color);
  font-size: 1.25rem;
  flex-shrink: 0;
}

.article-info {
  flex: 1;
}

.article-title {
  font-size: 1.0625rem;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--text-primary);
}

.article-title a {
  color: inherit;
}

.article-title a:hover {
  color: var(--accent-dark);
  text-decoration: none;
}

.article-summary {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 8px;
}

.article-meta {
  display: flex;
  gap: 16px;
  font-size: 0.8125rem;
  color: var(--text-muted);
}

/* ===== 文章详情页 ===== */
.article-page {
  padding: 40px 0;
}

.article-container {
  max-width: 800px;
  margin: 0 auto;
}

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

.article-page-title {
  font-size: 1.75rem;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.article-page-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 0.875rem;
  color: var(--text-secondary);
}

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

.article-body {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--text-primary);
}

.article-body h2 {
  font-size: 1.375rem;
  font-weight: 600;
  margin: 32px 0 16px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--accent-light);
}

.article-body h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin: 24px 0 12px;
  color: var(--text-primary);
}

.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 strong {
  color: var(--accent-dark);
}

/* ===== 反馈按钮 ===== */
.feedback-section {
  margin-top: 40px;
  padding: 24px;
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
  text-align: center;
}

.feedback-title {
  font-size: 1rem;
  font-weight: 500;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.feedback-btns {
  display: flex;
  gap: 12px;
  justify-content: center;
}

.feedback-btn {
  padding: 10px 24px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  background: var(--bg-primary);
  color: var(--text-secondary);
  font-size: 0.9375rem;
  cursor: pointer;
  transition: all 0.2s;
}

.feedback-btn:hover {
  border-color: var(--accent-color);
  color: var(--accent-dark);
}

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

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

/* ===== 相关文章/问题 ===== */
.related-section {
  margin-top: 40px;
  padding-top: 32px;
  border-top: 1px solid var(--border-color);
}

.related-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 20px;
  color: var(--text-primary);
}

.related-list {
  list-style: none;
}

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

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

.related-item a {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text-primary);
}

.related-item a:hover {
  color: var(--accent-dark);
  text-decoration: none;
}

.related-item a::before {
  content: "▶";
  color: var(--accent-color);
  font-size: 0.75rem;
}

/* ===== 三栏文章区 ===== */
.three-col-section {
  padding: 40px 0;
  background: var(--bg-secondary);
}

.three-col-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.col-title {
  font-size: 1.0625rem;
  font-weight: 600;
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--accent-color);
  color: var(--text-primary);
}

.col-list {
  list-style: none;
}

.col-list li {
  padding: 10px 0;
  border-bottom: 1px solid var(--border-color);
}

.col-list li:last-child {
  border-bottom: none;
}

.col-list a {
  color: var(--text-secondary);
  font-size: 0.9375rem;
}

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

/* ===== 404 页面 ===== */
.error-page {
  min-height: calc(100vh - var(--header-height) - 200px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 60px 0;
  text-align: center;
}

.error-code {
  font-size: 8rem;
  font-weight: 700;
  color: var(--accent-color);
  line-height: 1;
  margin-bottom: 16px;
}

.error-title {
  font-size: 1.75rem;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.error-desc {
  font-size: 1.0625rem;
  color: var(--text-secondary);
  margin-bottom: 32px;
}

.error-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  font-size: 1rem;
  font-weight: 500;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.2s;
  text-decoration: none;
}

.btn-primary {
  background: var(--accent-color);
  border: 1px solid var(--accent-color);
  color: #fff;
}

.btn-primary:hover {
  background: var(--accent-dark);
  border-color: var(--accent-dark);
  text-decoration: none;
}

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

.btn-secondary:hover {
  border-color: var(--accent-color);
  color: var(--accent-dark);
  text-decoration: none;
}

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

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 32px;
}

.footer-brand {
  max-width: 300px;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 12px;
}

.footer-desc {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.footer-title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.footer-links {
  list-style: none;
}

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

.footer-links a {
  color: var(--text-secondary);
  font-size: 0.9375rem;
}

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

.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid var(--border-color);
  text-align: center;
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* ===== 分类页头部 ===== */
.category-header {
  padding: 40px 0;
  background: var(--bg-secondary);
  text-align: center;
}

.category-title-main {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.category-stats {
  font-size: 1rem;
  color: var(--text-secondary);
}

/* ===== 响应式设计 ===== */
@media (max-width: 1024px) {
  .three-col-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

@media (max-width: 768px) {
  :root {
    --header-height: 56px;
  }

  .header-inner {
    flex-wrap: wrap;
    height: auto;
    padding: 12px 0;
  }

  .nav {
    width: 100%;
    justify-content: center;
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px solid var(--border-color);
  }

  .hero {
    padding: 40px 0;
  }

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

  .hero-desc {
    font-size: 1rem;
  }

  .category-filter {
    gap: 8px;
  }

  .category-btn {
    padding: 8px 14px;
    font-size: 0.875rem;
  }

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

  .three-col-grid {
    grid-template-columns: 1fr;
  }

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

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

  .error-actions {
    flex-direction: column;
    align-items: center;
  }

  .article-page-title {
    font-size: 1.375rem;
  }

  .article-body h2 {
    font-size: 1.125rem;
  }

  .article-body h3 {
    font-size: 1rem;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 12px;
  }

  .search-input {
    padding: 12px 44px 12px 16px;
    font-size: 0.9375rem;
  }

  .accordion-header {
    padding: 14px 16px;
  }

  .accordion-title {
    font-size: 0.9375rem;
  }

  .accordion-body {
    padding: 0 16px 16px;
    font-size: 0.9375rem;
  }

  .article-item {
    padding: 16px;
  }

  .article-icon {
    width: 40px;
    height: 40px;
    font-size: 1rem;
  }

  .feedback-btns {
    flex-direction: column;
  }

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

/* ===== 打印样式 ===== */
@media print {
  .header,
  .footer,
  .search-box,
  .category-filter,
  .feedback-section,
  .related-section {
    display: none;
  }

  .article-body {
    font-size: 12pt;
    line-height: 1.6;
  }
}