/* ==========================================================================
   Strong VPN - 纯原生极简高速 CSS 样式表 (浅色优雅商务风)
   零外部依赖 | 秒开渲染 | 全响应式设计 | 现代清爽高质感
   ========================================================================== */

:root {
  --bg-body: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-hover: #ffffff;
  --bg-surface: #f1f5f9;
  --border-color: #e2e8f0;
  --border-highlight: #38bdf8;
  
  --primary-cyan: #0284c7;
  --primary-blue: #2563eb;
  --accent-green: #059669;
  --accent-purple: #7c3aed;
  --accent-gold: #d97706;
  
  --gradient-primary: linear-gradient(135deg, #0284c7 0%, #2563eb 100%);
  --gradient-accent: linear-gradient(135deg, #059669 0%, #0284c7 100%);
  --gradient-glow: radial-gradient(circle at 50% 0%, rgba(2, 132, 199, 0.08) 0%, rgba(248, 250, 252, 0) 65%);

  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;

  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --shadow-sm: 0 2px 4px rgba(15, 23, 42, 0.04), 0 1px 2px rgba(15, 23, 42, 0.03);
  --shadow-md: 0 4px 12px -2px rgba(15, 23, 42, 0.06), 0 2px 6px -1px rgba(15, 23, 42, 0.04);
  --shadow-lg: 0 12px 28px -6px rgba(37, 99, 235, 0.18), 0 4px 10px -2px rgba(15, 23, 42, 0.05);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-body);
  color: var(--text-primary);
  line-height: 1.6;
  background-image: var(--gradient-glow);
  background-repeat: no-repeat;
  background-attachment: fixed;
  min-height: 100vh;
  overflow-x: hidden;
}

/* 容器与通用排版 */
.container {
  width: 100%;
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

a {
  color: inherit;
  text-decoration: none;
}

ul, ol {
  list-style: none;
}

/* 按钮规范与呼吁性（CTA）设计 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-weight: 600;
  font-size: 1rem;
  padding: 14px 28px;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
  border: 1px solid transparent;
  min-height: 48px;
  user-select: none;
  touch-action: manipulation;
}

.btn-primary {
  background: var(--gradient-primary);
  color: #ffffff;
  font-weight: 700;
  box-shadow: 0 4px 16px rgba(2, 132, 199, 0.35);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(2, 132, 199, 0.45);
  filter: brightness(1.05);
  color: #ffffff;
}

.btn-secondary {
  background: #ffffff;
  border: 1px solid #cbd5e1;
  color: #1e293b;
  box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
  background: #f8fafc;
  border-color: var(--primary-cyan);
  color: var(--primary-cyan);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-block {
  width: 100%;
}

.btn-sm {
  padding: 8px 18px;
  font-size: 0.875rem;
  min-height: 38px;
}

/* 顶部导航栏 */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  background-color: rgba(255, 255, 255, 0.9);
  border-bottom: 1px solid var(--border-color);
  box-shadow: 0 1px 4px rgba(15, 23, 42, 0.04);
  padding: 16px 0;
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: var(--text-primary);
}

.brand-logo svg {
  width: 28px;
  height: 28px;
  fill: none;
  stroke: var(--primary-cyan);
  stroke-width: 2.2;
}

.brand-logo span {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-links a {
  color: var(--text-secondary);
  font-size: 0.95rem;
  font-weight: 500;
  transition: var(--transition);
}

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

.nav-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

/* 主视觉区 (Hero Section) */
.hero {
  padding: 80px 0 60px;
  text-align: center;
  position: relative;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 18px;
  background: #e0f2fe;
  border: 1px solid #bae6fd;
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  color: #0369a1;
  font-weight: 600;
  margin-bottom: 24px;
}

.hero-title {
  font-size: clamp(2.2rem, 5vw, 3.8rem);
  font-weight: 850;
  line-height: 1.18;
  letter-spacing: -1px;
  margin-bottom: 22px;
  color: var(--text-primary);
}

.hero-title .text-gradient {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: clamp(1.05rem, 2vw, 1.25rem);
  color: var(--text-secondary);
  max-width: 780px;
  margin: 0 auto 36px;
  line-height: 1.75;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  flex-wrap: wrap;
  margin-bottom: 50px;
}

/* 核心指标统计横条 */
.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  max-width: 960px;
  margin: 0 auto 36px;
  padding: 24px 30px;
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

/* 未来感企业总部视觉展示框 */
.hero-showcase {
  max-width: 1040px;
  margin: 0 auto;
  position: relative;
}

.showcase-frame {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid rgba(2, 132, 199, 0.25);
  box-shadow: 0 20px 40px -10px rgba(2, 132, 199, 0.15), 0 10px 20px -5px rgba(15, 23, 42, 0.08);
  background: #ffffff;
  transition: var(--transition);
}

.showcase-frame:hover {
  transform: translateY(-4px);
  box-shadow: 0 26px 50px -10px rgba(2, 132, 199, 0.22), 0 12px 24px -5px rgba(15, 23, 42, 0.1);
}

.showcase-img {
  width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
  aspect-ratio: 16 / 9;
}

.showcase-caption {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  background: linear-gradient(to top, rgba(15, 23, 42, 0.88) 0%, rgba(15, 23, 42, 0.5) 60%, transparent 100%);
  padding: 24px 28px 20px;
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  backdrop-filter: blur(4px);
}

.showcase-tag {
  display: inline-block;
  background: var(--gradient-primary);
  color: #ffffff;
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 1.2px;
  padding: 4px 12px;
  border-radius: var(--radius-full);
}

.showcase-caption p {
  font-size: 0.95rem;
  color: #f1f5f9;
  font-weight: 500;
  margin: 0;
}

.stat-item {
  text-align: center;
}

.stat-number {
  font-size: 1.85rem;
  font-weight: 800;
  color: var(--primary-cyan);
  line-height: 1.2;
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* 通用区块头 */
.section {
  padding: 80px 0;
}

.section-alt {
  background-color: #f1f5f9;
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 50px;
}

.section-tag {
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--primary-cyan);
  letter-spacing: 1.5px;
  margin-bottom: 10px;
}

.section-title {
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -0.5px;
  margin-bottom: 14px;
  color: var(--text-primary);
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* 核心优势网格 */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 32px 28px;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.feature-card:hover {
  transform: translateY(-4px);
  border-color: #93c5fd;
  box-shadow: 0 12px 26px rgba(15, 23, 42, 0.08);
}

.feature-icon-wrapper {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-sm);
  background: #e0f2fe;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--primary-cyan);
}

.feature-icon-wrapper svg {
  width: 28px;
  height: 28px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.feature-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.feature-text {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* 流媒体与 AI 支持专区 */
.unlock-wrapper {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 30px;
}

.unlock-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px;
  position: relative;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}

.unlock-card:hover {
  border-color: #93c5fd;
  box-shadow: 0 14px 30px rgba(15, 23, 42, 0.08);
}

.unlock-badge {
  display: inline-block;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.badge-ai {
  background: #ede9fe;
  color: #6d28d9;
  border: 1px solid #ddd6fe;
}

.badge-stream {
  background: #d1fae5;
  color: #047857;
  border: 1px solid #a7f3d0;
}

.unlock-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.unlock-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 24px;
}

.pill-group {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 24px;
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: #f8fafc;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  color: #334155;
  font-weight: 500;
}

.pill-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent-green);
}

.unlock-checklist {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding-top: 18px;
  border-top: 1px solid var(--border-color);
}

.checklist-item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.checklist-item svg {
  width: 16px;
  height: 16px;
  stroke: var(--accent-green);
  flex-shrink: 0;
}

/* 套餐价格对比表 */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  align-items: stretch;
}

.pricing-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px 30px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}

.pricing-card:hover {
  transform: translateY(-5px);
  border-color: #cbd5e1;
  box-shadow: var(--shadow-md);
}

.pricing-card.popular {
  border: 2px solid var(--primary-cyan);
  background: #ffffff;
  box-shadow: var(--shadow-lg);
  transform: scale(1.03);
  z-index: 2;
}

.pricing-card.popular:hover {
  transform: scale(1.04) translateY(-4px);
  box-shadow: 0 16px 36px -4px rgba(2, 132, 199, 0.25);
}

.popular-tag {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--gradient-primary);
  color: #ffffff;
  font-size: 0.78rem;
  font-weight: 800;
  padding: 4px 16px;
  border-radius: var(--radius-full);
  letter-spacing: 1px;
  text-transform: uppercase;
  box-shadow: 0 4px 12px rgba(2, 132, 199, 0.35);
}

.plan-header {
  margin-bottom: 20px;
}

.plan-name {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 6px;
  color: var(--text-primary);
}

.plan-tagline {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.plan-price-wrapper {
  margin-bottom: 24px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-color);
}

.plan-currency {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--primary-cyan);
}

.plan-price {
  font-size: 2.75rem;
  font-weight: 850;
  line-height: 1;
  color: var(--text-primary);
}

.plan-period {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.plan-features {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-bottom: 30px;
  flex-grow: 1;
}

.plan-feature-item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.92rem;
  color: var(--text-secondary);
}

.plan-feature-item svg {
  width: 18px;
  height: 18px;
  stroke: var(--accent-green);
  flex-shrink: 0;
}

.plan-feature-item.highlight {
  color: var(--text-primary);
  font-weight: 600;
}

/* 用户评价 (Testimonials) */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.testimonial-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}

.testimonial-card:hover {
  transform: translateY(-3px);
  border-color: #93c5fd;
  box-shadow: 0 8px 20px rgba(15, 23, 42, 0.06);
}

.stars {
  display: flex;
  gap: 3px;
  color: var(--accent-gold);
  margin-bottom: 14px;
}

.stars svg {
  width: 16px;
  height: 16px;
  fill: currentColor;
}

.testimonial-text {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 20px;
}

.testimonial-author {
  display: flex;
  align-items: center;
  gap: 12px;
  padding-top: 14px;
  border-top: 1px solid var(--border-color);
}

.author-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: #e0f2fe;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: var(--primary-cyan);
  font-size: 0.95rem;
}

.author-info h4 {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-primary);
}

.author-info p {
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* 常见问题解答 (FAQ) */
.faq-wrapper {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.faq-item {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}

.faq-item:hover {
  border-color: #cbd5e1;
}

.faq-summary {
  padding: 20px 24px;
  font-weight: 600;
  font-size: 1.05rem;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
  color: var(--text-primary);
}

.faq-summary::-webkit-details-marker {
  display: none;
}

.faq-summary::after {
  content: "+";
  font-size: 1.4rem;
  font-weight: 400;
  color: var(--primary-cyan);
  transition: var(--transition);
}

.faq-item[open] .faq-summary::after {
  content: "−";
  transform: rotate(180deg);
}

.faq-content {
  padding: 0 24px 22px;
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.7;
  border-top: 1px solid #f1f5f9;
}

/* 底部 CTA 激励横幅 */
.cta-banner {
  margin: 40px auto 80px;
  background: linear-gradient(135deg, #eff6ff 0%, #e0f2fe 100%);
  border: 1px solid #bae6fd;
  border-radius: var(--radius-lg);
  padding: 50px 30px;
  text-align: center;
  box-shadow: 0 8px 24px rgba(2, 132, 199, 0.08);
}

.cta-banner h2 {
  font-size: clamp(1.8rem, 3vw, 2.4rem);
  font-weight: 800;
  margin-bottom: 14px;
  color: var(--text-primary);
}

.cta-banner p {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 620px;
  margin: 0 auto 30px;
}

/* 页脚 (Footer) - 严格只保留四个标题 */
.footer {
  background-color: #ffffff;
  border-top: 1px solid var(--border-color);
  padding: 48px 0 36px;
  text-align: center;
}

.footer-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 40px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.footer-nav a {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-secondary);
  transition: var(--transition);
  position: relative;
  padding: 4px 8px;
}

.footer-nav a:hover {
  color: var(--primary-cyan);
}

.footer-copyright {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* 内容详情页面公共样式 (关于我们/服务条款/隐私政策/网站地图) */
.page-container {
  max-width: 880px;
  margin: 40px auto 80px;
  padding: 40px 32px;
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

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

.page-title {
  font-size: 2.2rem;
  font-weight: 800;
  margin-bottom: 10px;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.page-subtitle {
  color: var(--text-muted);
  font-size: 0.95rem;
}

.content-section {
  margin-bottom: 32px;
}

.content-section h2 {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.content-section h2::before {
  content: "";
  display: inline-block;
  width: 4px;
  height: 18px;
  background: var(--primary-cyan);
  border-radius: 2px;
}

.content-section p {
  color: var(--text-secondary);
  font-size: 0.98rem;
  line-height: 1.75;
  margin-bottom: 12px;
}

.content-section ul {
  padding-left: 20px;
  margin-bottom: 16px;
}

.content-section ul li {
  list-style-type: disc;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
  margin-bottom: 8px;
}

.back-home-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--primary-cyan);
  font-weight: 600;
  margin-bottom: 24px;
  font-size: 0.95rem;
}

.back-home-link:hover {
  text-decoration: underline;
}

/* ==========================================================================
   响应式适配 (自带媒体查询 @media)
   确保在手机端完美单栏显示，按钮适合手指触碰点击
   ========================================================================== */

@media (max-width: 1024px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .testimonials-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  /* 导航折叠与移动端适配 */
  .nav-links {
    display: none; /* 保持移动端极简秒开 */
  }
  
  .navbar {
    padding: 12px 0;
  }
  
  /* 英雄区手机单栏化 */
  .hero {
    padding: 50px 0 40px;
  }
  
  .hero-actions {
    flex-direction: column;
    width: 100%;
  }
  
  .hero-actions .btn {
    width: 100%;
  }
  
  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    padding: 18px 16px;
  }
  
  .stat-number {
    font-size: 1.5rem;
  }
  
  /* 核心优势单栏 */
  .features-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  
  /* 流媒体与 AI 单栏 */
  .unlock-wrapper {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  
  .unlock-card {
    padding: 24px 20px;
  }
  
  /* 套餐对比单栏展示与恢复层叠比例 */
  .pricing-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  
  .pricing-card.popular {
    transform: none;
  }
  
  .pricing-card.popular:hover {
    transform: translateY(-4px);
  }
  
  .pricing-card {
    padding: 30px 22px;
  }
  
  /* 用户评价单栏 */
  .testimonials-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  
  /* 底部 CTA 与页脚 */
  .cta-banner {
    padding: 36px 18px;
    margin: 30px auto 50px;
  }
  
  .footer-nav {
    flex-direction: column;
    gap: 18px;
  }
  
  /* 手指触控友好的按钮尺寸与间距 */
  .btn {
    min-height: 50px;
    font-size: 1.05rem;
    padding: 14px 24px;
  }
  
  .page-container {
    padding: 24px 18px;
    margin: 20px auto 40px;
  }

  .article-grid {
    grid-template-columns: 1fr;
    gap: 18px;
  }
}

/* ==========================================================================
   高科技网格卡片 (Grid Cards) & SEO 文章排版样式
   ========================================================================== */
.article-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
  margin-top: 32px;
}

@media (max-width: 1024px) and (min-width: 769px) {
  .article-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.article-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 26px 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
}

.article-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--gradient-primary);
  opacity: 0;
  transition: var(--transition);
}

.article-card:hover {
  transform: translateY(-5px);
  border-color: #93c5fd;
  box-shadow: 0 12px 28px rgba(15, 23, 42, 0.08);
}

.article-card:hover::before {
  opacity: 1;
}

.article-card-tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--primary-cyan);
  background: #e0f2fe;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  margin-bottom: 12px;
  align-self: flex-start;
}

.article-card-title {
  font-size: 1.12rem;
  font-weight: 750;
  line-height: 1.45;
  color: var(--text-primary);
  margin-bottom: 12px;
}

.article-card-title a {
  color: inherit;
  transition: var(--transition);
}

.article-card-title a:hover {
  color: var(--primary-cyan);
}

.article-card-excerpt {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 20px;
  flex-grow: 1;
}

.article-card-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--text-muted);
  padding-top: 14px;
  border-top: 1px solid var(--border-color);
}

.article-card-link {
  font-weight: 700;
  color: var(--primary-cyan);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.article-card-link:hover {
  text-decoration: underline;
}

/* 单篇文章详情页排版 */
.article-header {
  margin-bottom: 30px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border-color);
}

.article-meta-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-top: 12px;
}

.article-body {
  font-size: 1.02rem;
  line-height: 1.85;
  color: var(--text-secondary);
}

.article-body h2 {
  font-size: 1.45rem;
  font-weight: 750;
  color: var(--text-primary);
  margin: 36px 0 16px;
  padding-left: 12px;
  border-left: 4px solid var(--primary-cyan);
}

.article-body h3 {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 24px 0 12px;
}

.article-body p {
  margin-bottom: 18px;
}

.article-body ul, .article-body ol {
  margin: 16px 0 20px 24px;
}

.article-body li {
  margin-bottom: 10px;
  line-height: 1.75;
}

.article-callout {
  background: #eff6ff;
  border: 1px solid #bfdbfe;
  border-radius: var(--radius-md);
  padding: 20px 24px;
  margin: 28px 0;
  color: #1e3a8a;
}

.article-callout strong {
  color: #1e40af;
}

.article-footer-nav {
  margin-top: 50px;
  padding-top: 24px;
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}