/* 奈云 官方落地页 - 浅色极简精美样式表 */

:root {
  --bg-primary: #f8fafc;
  --bg-card: #ffffff;
  --bg-subtle: #f1f5f9;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --brand-primary: #2563eb;
  --brand-gradient: linear-gradient(135deg, #2563eb 0%, #4f46e5 100%);
  --brand-hover: linear-gradient(135deg, #1d4ed8 0%, #4338ca 100%);
  --accent-light: #eff6ff;
  --border-color: #e2e8f0;
  --border-hover: #cbd5e1;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 30px rgba(37, 99, 235, 0.1);
  --shadow-hover: 0 20px 40px rgba(37, 99, 235, 0.15);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

/* 全局重置 */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* 顶部导航 */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  transition: all 0.3s ease;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -0.5px;
}

.logo-icon {
  width: 38px;
  height: 38px;
  background: var(--brand-gradient);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  box-shadow: var(--shadow-sm);
}

.logo-icon svg {
  width: 22px;
  height: 22px;
  fill: currentColor;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color 0.2s;
}

.nav-link:hover {
  color: var(--brand-primary);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* 按钮通用 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  transition: all 0.25s ease;
  cursor: pointer;
  border: none;
  white-space: nowrap;
}

.btn-primary {
  background: var(--brand-gradient);
  color: #ffffff;
  box-shadow: var(--shadow-lg);
}

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

.btn-outline {
  background-color: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
}

.btn-outline:hover {
  border-color: var(--brand-primary);
  color: var(--brand-primary);
  background-color: var(--accent-light);
  transform: translateY(-2px);
}

.btn-lg {
  padding: 16px 36px;
  font-size: 1.1rem;
}

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

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background-color: var(--accent-light);
  border: 1px solid rgba(37, 99, 235, 0.2);
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--brand-primary);
  margin-bottom: 24px;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -1px;
  margin-bottom: 20px;
  color: var(--text-primary);
}

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

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 720px;
  margin: 0 auto 36px;
  font-weight: 400;
}

.hero-cta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 48px;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  max-width: 900px;
  margin: 0 auto;
  padding: 24px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

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

.stat-value {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--brand-primary);
}

.stat-label {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* 核心优势板块 */
.section {
  padding: 80px 0;
}

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

.section-header {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 56px;
}

.section-subtitle {
  color: var(--brand-primary);
  font-weight: 700;
  text-transform: uppercase;
  font-size: 0.875rem;
  letter-spacing: 1px;
  margin-bottom: 8px;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -0.5px;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.feature-card {
  background: var(--bg-card);
  padding: 32px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  transition: all 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(37, 99, 235, 0.3);
}

.feature-icon {
  width: 56px;
  height: 56px;
  background: var(--accent-light);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--brand-primary);
  margin-bottom: 20px;
}

.feature-icon svg {
  width: 28px;
  height: 28px;
  fill: currentColor;
}

.feature-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--text-primary);
}

.feature-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* 流媒体与 AI 支持 */
.support-tags {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 16px;
  margin-top: 36px;
}

.support-tag {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 24px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-sm);
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text-primary);
}

.support-tag svg {
  width: 22px;
  height: 22px;
}

/* 套餐价格对比 */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 24px;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  display: flex;
  flex-direction: column;
  position: relative;
  box-shadow: var(--shadow-sm);
  transition: all 0.3s ease;
}

.pricing-card.featured {
  border: 2px solid var(--brand-primary);
  box-shadow: var(--shadow-lg);
  transform: scale(1.03);
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--brand-gradient);
  color: #ffffff;
  padding: 4px 16px;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.5px;
}

.plan-name {
  font-size: 1.35rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.plan-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-bottom: 24px;
}

.plan-price {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 24px;
}

.plan-price span {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-muted);
}

.plan-features {
  list-style: none;
  margin-bottom: 32px;
  flex: 1;
}

.plan-features li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.925rem;
  color: var(--text-secondary);
  margin-bottom: 12px;
}

.plan-features svg {
  width: 18px;
  height: 18px;
  fill: #10b981;
  flex-shrink: 0;
}

.pricing-card .btn {
  width: 100%;
}

/* FAQ 常见问题 */
.faq-grid {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sm);
}

.faq-question {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.faq-answer {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* 用户评价 */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow-sm);
}

.review-stars {
  color: #f59e0b;
  margin-bottom: 14px;
  font-size: 1.1rem;
}

.review-content {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 20px;
  line-height: 1.6;
}

.review-author {
  display: flex;
  align-items: center;
  gap: 12px;
}

.author-avatar {
  width: 44px;
  height: 44px;
  background: var(--brand-gradient);
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  font-weight: 700;
}

.author-info h4 {
  font-size: 0.95rem;
  font-weight: 700;
}

.author-info p {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* 页脚 Footer - 规范严格：只保留 4 个标题链接 */
.footer {
  background-color: #ffffff;
  border-top: 1px solid var(--border-color);
  padding: 48px 0;
  margin-top: 40px;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
}

.footer-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 36px;
  flex-wrap: wrap;
}

.footer-nav a {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-secondary);
  transition: color 0.2s ease;
}

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

.footer-copy {
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* 附属页面通用容器样式 (About, Terms, Privacy, Sitemap) */
.page-header {
  padding: 60px 0 40px;
  text-align: center;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 40px;
}

.page-title {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.page-desc {
  font-size: 1.1rem;
  color: var(--text-secondary);
}

.content-box {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 40px;
  box-shadow: var(--shadow-sm);
  margin-bottom: 60px;
  line-height: 1.8;
}

.content-box h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin: 32px 0 16px;
  color: var(--text-primary);
  border-bottom: 2px solid var(--accent-light);
  padding-bottom: 8px;
}

.content-box h2:first-child {
  margin-top: 0;
}

.content-box p {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-bottom: 16px;
}

.content-box ul {
  margin: 0 0 24px 24px;
  color: var(--text-secondary);
}

.content-box li {
  margin-bottom: 8px;
}

/* 移动端响应式 @media (max-width: 768px) */
@media (max-width: 768px) {
  .header-inner {
    height: 64px;
  }
  
  .nav-links {
    display: none; /* 移动端精简顶部，突出注册与购买按钮 */
  }

  .hero {
    padding: 48px 0 36px;
  }

  .hero-title {
    font-size: 2.25rem;
  }

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

  .hero-cta {
    flex-direction: column;
    width: 100%;
  }

  .hero-cta .btn {
    width: 100%;
    min-height: 50px;
  }

  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    padding: 16px;
  }

  .stat-value {
    font-size: 1.4rem;
  }

  .section {
    padding: 48px 0;
  }

  .section-title {
    font-size: 1.75rem;
  }

  .features-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

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

  .pricing-card.featured {
    transform: none;
  }

  .reviews-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .footer-nav {
    flex-direction: column;
    gap: 16px;
  }

  .content-box {
    padding: 24px;
  }
}

/* 高科技网格卡片 (Grid Cards) 布局 */
.article-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 28px;
  margin-bottom: 60px;
}

.art-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 28px;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-sm);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.art-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(37, 99, 235, 0.4);
}

.art-card-tag {
  align-self: flex-start;
  padding: 4px 12px;
  background: var(--accent-light);
  color: var(--brand-primary);
  font-size: 0.8rem;
  font-weight: 700;
  border-radius: var(--radius-full);
  margin-bottom: 16px;
  border: 1px solid rgba(37, 99, 235, 0.15);
}

.art-card-title {
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1.4;
  margin-bottom: 12px;
}

.art-card-title a {
  transition: color 0.2s;
}

.art-card-title a:hover {
  color: var(--brand-primary);
}

.art-card-meta {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.art-card-desc {
  font-size: 0.925rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 24px;
  flex: 1;
}

.art-card-footer {
  margin-top: auto;
}

/* 关联外部权重 DOFOLLOW 样式 */
.dofollow-link {
  color: var(--brand-primary);
  font-weight: 700;
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: opacity 0.2s;
}

.dofollow-link:hover {
  opacity: 0.85;
}