@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600&family=Outfit:wght@400;500;600;700&display=swap');

/* ==========================================
   CSS 变量与主题设计 (莫兰迪极简冷灰调)
   ========================================== */
:root {
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --accent-color: #0f766e;        /* 静谧的松石绿，传递稳重、自然的品质感 */
  --accent-hover: #115e59;
  --border-color: #f1f5f9;
  --card-shadow: 0 10px 25px -5px rgba(15, 23, 42, 0.04), 0 8px 10px -6px rgba(15, 23, 42, 0.04);
  --hover-shadow: 0 20px 25px -5px rgba(15, 23, 42, 0.08), 0 10px 10px -6px rgba(15, 23, 42, 0.08);
  --font-title: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Microsoft YaHei", sans-serif;
  --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --container-width: 1100px;
}

/* 优雅暗色模式自适应支持 */
@media (prefers-color-scheme: dark) {
  :root {
    --bg-primary: #0b0f19;
    --bg-secondary: #131a26;
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-muted: #64748b;
    --accent-color: #14b8a6;
    --accent-hover: #2dd4bf;
    --border-color: #1e293b;
    --card-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
    --hover-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
  }
}

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

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

body {
  font-family: var(--font-body);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

ul {
  list-style: none;
}

/* ==========================================
   公共布局组件
   ========================================== */
.container {
  width: 90%;
  max-width: var(--container-width);
  margin: 0 auto;
}

.section-padding {
  padding: 80px 0;
}

@media (max-width: 768px) {
  .section-padding {
    padding: 50px 0;
  }
}

/* ==========================================
   导航栏 (Header)
   ========================================== */
.site-header {
  background-color: rgba(var(--bg-secondary), 0.8);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-secondary); /* 回退 */
}

/* 如果支持模糊，使用半透明 */
@supports (backdrop-filter: blur(12px)) {
  .site-header {
    background-color: rgba(255, 255, 255, 0.75);
  }
  @media (prefers-color-scheme: dark) {
    .site-header {
      background-color: rgba(19, 26, 38, 0.75);
    }
  }
}

.nav-wrapper {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 70px;
}

.logo {
  font-family: var(--font-title);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent-color);
  letter-spacing: -0.5px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo::before {
  content: '';
  display: inline-block;
  width: 12px;
  height: 12px;
  background-color: var(--accent-color);
  border-radius: 3px;
}

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

.nav-links a {
  font-weight: 500;
  font-size: 0.95rem;
  color: var(--text-secondary);
  position: relative;
  padding: 4px 0;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--accent-color);
  transition: var(--transition-smooth);
}

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

.nav-links a:hover::after {
  width: 100%;
}

@media (max-width: 600px) {
  .nav-links {
    gap: 16px;
  }
  .nav-links a {
    font-size: 0.85rem;
  }
}

/* ==========================================
   Hero 主视觉区
   ========================================== */
.hero-section {
  position: relative;
  overflow: hidden;
  padding: 100px 0 60px;
}

.hero-content {
  max-width: 700px;
}

.hero-subtitle {
  font-family: var(--font-title);
  font-size: 1rem;
  font-weight: 600;
  color: var(--accent-color);
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: 12px;
}

.hero-title {
  font-family: var(--font-title);
  font-size: 3rem;
  font-weight: 700;
  line-height: 1.25;
  color: var(--text-primary);
  margin-bottom: 20px;
  letter-spacing: -1px;
}

.hero-title span {
  background: linear-gradient(135deg, var(--text-primary), var(--accent-color));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-description {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 30px;
  max-width: 600px;
}

@media (max-width: 768px) {
  .hero-section {
    padding: 60px 0 40px;
  }
  .hero-title {
    font-size: 2.2rem;
  }
}

/* ==========================================
   内容过滤/分类导航
   ========================================== */
.filter-wrapper {
  display: flex;
  justify-content: flex-start;
  gap: 12px;
  margin-bottom: 40px;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 16px;
}

.filter-btn {
  background: none;
  border: none;
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 8px 16px;
  border-radius: 20px;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.filter-btn:hover {
  color: var(--accent-color);
  background-color: rgba(15, 118, 110, 0.05);
}

.filter-btn.active {
  color: #ffffff;
  background-color: var(--accent-color);
}

@media (prefers-color-scheme: dark) {
  .filter-btn.active {
    color: var(--bg-primary);
  }
}

/* ==========================================
   卡片列表 (Card Grid)
   ========================================== */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 30px;
}

.card {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: var(--card-shadow);
  transition: var(--transition-smooth);
  display: flex;
  flex-direction: column;
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: var(--hover-shadow);
  border-color: rgba(15, 118, 110, 0.15);
}

.card-image {
  height: 200px;
  background-color: #e2e8f0;
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

@media (prefers-color-scheme: dark) {
  .card-image {
    background-color: #1e293b;
  }
}

.card-image-placeholder {
  font-family: var(--font-title);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-muted);
  text-align: center;
  padding: 20px;
}

.card-body {
  padding: 24px;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.card-tag {
  display: inline-block;
  align-self: flex-start;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-color);
  background-color: rgba(15, 118, 110, 0.08);
  padding: 4px 10px;
  border-radius: 12px;
  margin-bottom: 14px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.card-title {
  font-family: var(--font-title);
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--text-primary);
  margin-bottom: 12px;
}

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

.card-excerpt {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 20px;
  flex-grow: 1;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border-color);
  padding-top: 16px;
}

/* ==========================================
   文章详情页排版
   ========================================== */
.article-header {
  text-align: center;
  max-width: 800px;
  margin: 40px auto 60px;
}

.article-meta {
  display: flex;
  justify-content: center;
  gap: 20px;
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 20px;
}

.article-title {
  font-family: var(--font-title);
  font-size: 2.75rem;
  font-weight: 700;
  line-height: 1.25;
  color: var(--text-primary);
  letter-spacing: -1px;
}

.article-content {
  max-width: 750px;
  margin: 0 auto;
  font-size: 1.05rem;
  color: var(--text-secondary);
}

.article-content p {
  margin-bottom: 24px;
}

.article-content h2 {
  font-family: var(--font-title);
  font-size: 1.75rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 40px 0 20px;
}

.article-content h3 {
  font-family: var(--font-title);
  font-size: 1.35rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 30px 0 16px;
}

.article-content blockquote {
  border-left: 4px solid var(--accent-color);
  padding-left: 20px;
  margin: 30px 0;
  font-style: italic;
  color: var(--text-primary);
}

.article-content code {
  font-family: Consolas, Monaco, monospace;
  background-color: var(--border-color);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.9rem;
}

.back-to-home {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--accent-color);
  font-weight: 500;
  margin-bottom: 40px;
}

.back-to-home:hover {
  transform: translateX(-4px);
}

@media (max-width: 768px) {
  .article-title {
    font-size: 2rem;
  }
}

/* ==========================================
   页脚 (Footer) - 特别加强备案栏的显眼性与规范性
   ========================================== */
.site-footer {
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 40px 0;
  margin-top: auto;
}

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

.footer-logo {
  font-family: var(--font-title);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.footer-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
  max-width: 400px;
}

/* 备案底栏样式：严格符合工信部和公安备案标准 */
.beian-info {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  margin-top: 12px;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.beian-link {
  color: var(--text-secondary);
  font-weight: 500;
  border-bottom: 1px dashed var(--text-muted);
  padding-bottom: 2px;
}

.beian-link:hover {
  color: var(--accent-color);
  border-bottom-color: var(--accent-color);
}