/* ==========================================================================
   一分机场 (Yifen Jichang) - 浅色极简科技风格统一样式表
   特点：纯 CSS，无需 JS 库，极致加载速度，全端响应式
   ========================================================================== */

/* 1. 全局变量定义 (浅色调) */
:root {
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  --bg-card: #ffffff;
  
  --text-main: #0f172a;
  --text-muted: #475569;
  --text-light: #64748b;
  
  --primary-color: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-gradient: linear-gradient(135deg, #2563eb 0%, #3b82f6 100%);
  --accent-color: #059669;
  --accent-light: #ecfdf5;
  
  --border-color: #e2e8f0;
  --border-hover: #cbd5e1;
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.06), 0 2px 4px -1px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 10px 25px -3px rgba(37, 99, 235, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-card: 0 4px 20px -2px rgba(15, 23, 42, 0.06);

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  
  --max-width: 1200px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

/* 2. 基础重置 */
*, *::before, *::after {
  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-secondary);
  color: var(--text-main);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

ul, ol {
  list-style: none;
}

/* 3. 通用容器与布局 */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section {
  padding: 5rem 0;
}

.section-alt {
  background-color: var(--bg-primary);
}

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

.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 0.75rem;
  letter-spacing: -0.02em;
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--text-muted);
  max-width: 650px;
  margin: 0 auto 3.5rem auto;
}

/* 4. 头部导航栏 (Header) */
.header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  padding: 1rem 0;
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.03em;
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: var(--primary-gradient);
  color: #ffffff;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 900;
  font-size: 1.1rem;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
}

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

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

/* 5. 呼吁性按钮 (CTA Buttons) */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-weight: 600;
  font-size: 1rem;
  padding: 0.85rem 1.8rem;
  border-radius: var(--radius-full);
  transition: all 0.25s ease;
  cursor: pointer;
  border: none;
  text-align: center;
  line-height: 1.2;
}

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

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 28px -4px rgba(37, 99, 235, 0.35);
  color: #ffffff;
}

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

.btn-secondary:hover {
  background-color: #e2e8f0;
  color: var(--text-main);
}

.btn-block {
  width: 100%;
}

.btn-sm {
  padding: 0.55rem 1.25rem;
  font-size: 0.875rem;
}

/* 6. Hero 主视觉区 */
.hero {
  padding: 5.5rem 0 4.5rem 0;
  background: radial-gradient(circle at 50% 0%, rgba(37, 99, 235, 0.06) 0%, rgba(255, 255, 255, 0) 70%), var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
}

.hero-content {
  max-width: 850px;
  margin: 0 auto;
  text-align: center;
}

.badge-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 1rem;
  background-color: rgba(37, 99, 235, 0.08);
  color: var(--primary-color);
  border: 1px solid rgba(37, 99, 235, 0.2);
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 1.75rem;
}

.hero-title {
  font-size: 3.25rem;
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin-bottom: 1.25rem;
  color: var(--text-main);
}

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

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 2.5rem;
  max-width: 720px;
  margin-left: auto;
  margin-right: auto;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.25rem;
  margin-bottom: 3rem;
}

.hero-features-list {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 1.75rem;
  font-size: 0.925rem;
  color: var(--text-light);
}

.hero-feature-item {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.hero-feature-item svg {
  color: var(--accent-color);
  width: 18px;
  height: 18px;
}

/* 7. 产品核心优势卡片 */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

.feature-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 2rem;
  box-shadow: var(--shadow-card);
  transition: all 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary-color);
  box-shadow: var(--shadow-lg);
}

.feature-icon {
  width: 52px;
  height: 52px;
  background-color: rgba(37, 99, 235, 0.08);
  color: var(--primary-color);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
}

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

.feature-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.6rem;
  color: var(--text-main);
}

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

/* 8. 高科技 SEO 文章网格卡片 (Grid Cards) */
.article-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  margin-top: 2rem;
}

.article-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-sm);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.article-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: var(--primary-gradient);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.article-card:hover {
  transform: translateY(-5px);
  border-color: var(--primary-color);
  box-shadow: var(--shadow-lg);
}

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

.article-tag {
  display: inline-block;
  align-self: flex-start;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--primary-color);
  background-color: rgba(37, 99, 235, 0.08);
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-full);
  margin-bottom: 0.85rem;
}

.article-card-title {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1.4;
  margin-bottom: 0.75rem;
}

.article-card-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 1.5rem;
  flex-grow: 1;
}

.article-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border-color);
  padding-top: 1rem;
  font-size: 0.825rem;
  color: var(--text-light);
}

/* 9. SEO 文章内部样式与 SEO 链接模块 */
.seo-link-box {
  background-color: var(--bg-tertiary);
  border-left: 4px solid var(--primary-color);
  padding: 1.25rem 1.5rem;
  border-radius: var(--radius-sm);
  margin: 2rem 0;
}

.seo-link-box h4 {
  font-size: 1rem;
  color: var(--text-main);
  margin-bottom: 0.5rem;
}

.seo-link-box ul {
  list-style: disc;
  padding-left: 1.25rem;
}

.seo-link-box li {
  margin-bottom: 0.4rem;
  font-size: 0.95rem;
}

.btn-back-wrap {
  margin-bottom: 2rem;
}

/* 10. 流媒体与 AI 支持专区 */
.media-ai-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
}

.media-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  display: flex;
  align-items: center;
  gap: 1.2rem;
  box-shadow: var(--shadow-sm);
  transition: all 0.25s ease;
}

.media-card:hover {
  border-color: var(--primary-color);
  box-shadow: var(--shadow-md);
}

.media-badge-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background-color: var(--bg-tertiary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1rem;
  color: var(--primary-color);
  flex-shrink: 0;
}

.media-info h4 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.2rem;
}

.media-info p {
  font-size: 0.85rem;
  color: var(--text-light);
}

/* 11. 套餐价格对比表 (Pricing Section) */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  align-items: stretch;
}

.pricing-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.25rem 1.5rem;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-card);
  position: relative;
  transition: all 0.3s ease;
}

.pricing-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.pricing-card.popular {
  border: 2px solid var(--primary-color);
  box-shadow: 0 12px 30px -4px rgba(37, 99, 235, 0.2);
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--primary-gradient);
  color: #ffffff;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.25rem 1rem;
  border-radius: var(--radius-full);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.pricing-header {
  text-align: center;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 1.5rem;
}

.pricing-name {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.75rem;
}

.pricing-price {
  font-size: 2.5rem;
  font-weight: 900;
  color: var(--text-main);
  line-height: 1;
}

.pricing-price span {
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-light);
}

.pricing-sub {
  font-size: 0.85rem;
  color: var(--primary-color);
  margin-top: 0.5rem;
  font-weight: 600;
}

.pricing-features {
  margin-bottom: 2rem;
  flex-grow: 1;
}

.pricing-features li {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 0.85rem;
}

.pricing-features svg {
  width: 18px;
  height: 18px;
  color: var(--accent-color);
  flex-shrink: 0;
}

/* 12. 用户评价 (User Reviews) */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.75rem;
}

.review-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  box-shadow: var(--shadow-sm);
}

.review-stars {
  color: #f59e0b;
  margin-bottom: 0.75rem;
  font-size: 1.1rem;
}

.review-text {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 1.25rem;
  font-style: italic;
}

.review-author {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

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

.author-info h5 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-main);
}

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

/* 13. FAQ 常见问题解答 */
.faq-grid {
  max-width: 850px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.faq-item {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
}

.faq-question {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.6rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.faq-question::before {
  content: "Q:";
  color: var(--primary-color);
  font-weight: 900;
}

.faq-answer {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.65;
  padding-left: 1.5rem;
}

/* 14. 极简页脚 (Footer) - 用户要求仅保留 4 个标题，在新页面打开 */
.footer {
  background-color: var(--bg-primary);
  border-top: 1px solid var(--border-color);
  padding: 3rem 0;
  text-align: center;
}

.footer-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 2.5rem;
  margin-bottom: 1.5rem;
}

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

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

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

/* 15. 子页面专用通用样式 (About, Terms, Privacy, Sitemap) */
.page-header {
  padding: 4rem 0 2.5rem 0;
  background-color: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
}

.page-title {
  font-size: 2.5rem;
  font-weight: 900;
  color: var(--text-main);
  margin-bottom: 0.5rem;
}

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

.page-body {
  padding: 4rem 0;
}

.content-box {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
  max-width: 900px;
  margin: 0 auto;
}

.content-box h2 {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-main);
  margin: 2rem 0 1rem 0;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-color);
}

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

.content-box p {
  color: var(--text-muted);
  line-height: 1.8;
  margin-bottom: 1.25rem;
  font-size: 1rem;
}

.content-box ul {
  list-style-type: disc;
  padding-left: 1.5rem;
  margin-bottom: 1.25rem;
  color: var(--text-muted);
}

.content-box li {
  margin-bottom: 0.5rem;
  line-height: 1.6;
}

/* 16. 媒体查询 - 响应式单栏适配 (Mobile & Tablet) */
@media (max-width: 992px) {
  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .grid-3, .reviews-grid, .article-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .section {
    padding: 3.5rem 0;
  }
  
  .hero-title {
    font-size: 2.25rem;
  }
  
  .hero-subtitle {
    font-size: 1.05rem;
  }

  .nav-wrapper {
    flex-direction: column;
    gap: 1rem;
  }

  .nav-links {
    gap: 1.25rem;
    font-size: 0.9rem;
  }

  .grid-3, .grid-4, .pricing-grid, .reviews-grid, .article-grid {
    grid-template-columns: 1fr;
  }
  
  .hero-actions {
    flex-direction: column;
    width: 100%;
  }

  .btn {
    width: 100%;
    min-height: 48px; /* 触控优化 */
  }

  .footer-nav {
    flex-direction: column;
    gap: 1rem;
  }

  .content-box {
    padding: 1.5rem;
  }
}