/* ==========================================================================
   杨帆云 (Yangfan Cloud) - 官方极速纯原生样式表
   零重型外部依赖 | 秒开性能 | 完美无障碍对比度与响应式适配
   ========================================================================== */

:root {
  --primary: #0284c7;
  --primary-hover: #0369a1;
  --primary-light: #e0f2fe;
  --accent: #2563eb;
  --accent-gradient: linear-gradient(135deg, #0284c7 0%, #2563eb 100%);
  --cta-color: #ea580c;
  --cta-hover: #c2410c;
  --bg-page: #0f172a;
  --bg-card: #1e293b;
  --bg-card-hover: #334155;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dark: #0f172a;
  --border-color: #334155;
  --border-light: #475569;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-full: 9999px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.4);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.5);
  --shadow-glow: 0 0 20px rgba(2, 132, 199, 0.35);
  --max-width: 1200px;
  --header-height: 72px;
}

/* 全局重置与基础设置 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.6;
  scroll-behavior: smooth;
  background-color: var(--bg-page);
  color: var(--text-main);
  text-size-adjust: 100%;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  position: relative;
}

/* 无障碍：跳至主要内容链接 */
.skip-link {
  position: absolute;
  top: -60px;
  left: 1rem;
  background: var(--cta-color);
  color: #ffffff;
  padding: 0.75rem 1.25rem;
  z-index: 9999;
  font-weight: 700;
  border-radius: var(--radius-sm);
  text-decoration: none;
  transition: top 0.2s ease-in-out;
}
.skip-link:focus {
  top: 1rem;
  outline: 3px solid #ffffff;
}

/* 锚点滚动留白 */
section[id], h2[id], h3[id] {
  scroll-margin-top: calc(var(--header-height) + 1.5rem);
}

/* 容器定义 */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

/* 顶部导航栏 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(15, 23, 42, 0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border-color);
  height: var(--header-height);
  display: flex;
  align-items: center;
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}
.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.35rem;
  font-weight: 800;
  color: #ffffff;
  text-decoration: none;
  letter-spacing: -0.025em;
}
.brand-logo:hover {
  opacity: 0.9;
}
.brand-icon {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: var(--accent-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  font-size: 1.1rem;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}
.nav-link {
  color: var(--text-muted);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  padding: 0.5rem 0.25rem;
  transition: color 0.2s ease;
  position: relative;
}
.nav-link:hover, .nav-link:focus-visible {
  color: #ffffff;
}
.nav-link.active {
  color: var(--primary);
  font-weight: 600;
}
.nav-badge {
  background: var(--primary);
  color: #ffffff;
  font-size: 0.75rem;
  padding: 0.15rem 0.45rem;
  border-radius: var(--radius-full);
  margin-left: 0.35rem;
}

/* 按钮通用组件 (触摸目标 >= 44x44px) */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  min-width: 44px;
  padding: 0.65rem 1.4rem;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  text-decoration: none;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all 0.2s ease;
  text-align: center;
}
.btn:focus-visible {
  outline: 3px solid var(--primary-light);
  outline-offset: 2px;
}
.btn-cta {
  background: var(--cta-color);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(234, 88, 12, 0.4);
}
.btn-cta:hover {
  background: var(--cta-hover);
  transform: translateY(-1px);
}
.btn-primary {
  background: var(--primary);
  color: #ffffff;
}
.btn-primary:hover {
  background: var(--primary-hover);
  transform: translateY(-1px);
}
.btn-secondary {
  background: rgba(255, 255, 255, 0.08);
  color: #ffffff;
  border-color: var(--border-light);
}
.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.16);
}
.btn-lg {
  min-height: 48px;
  padding: 0.85rem 1.85rem;
  font-size: 1.05rem;
}

/* 主视觉区 Hero */
.hero-section {
  padding: 4.5rem 0 3.5rem;
  text-align: center;
  position: relative;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(2, 132, 199, 0.15);
  border: 1px solid rgba(2, 132, 199, 0.4);
  color: #38bdf8;
  padding: 0.35rem 1rem;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
}
.hero-title {
  font-size: 2.75rem;
  line-height: 1.2;
  font-weight: 800;
  margin-bottom: 1.25rem;
  color: #ffffff;
  letter-spacing: -0.02em;
}
.hero-title .gradient-text {
  background: linear-gradient(135deg, #38bdf8 0%, #818cf8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero-subtitle {
  font-size: 1.35rem;
  color: #cbd5e1;
  font-weight: 600;
  margin-bottom: 1rem;
}
.hero-desc {
  max-width: 780px;
  margin: 0 auto 2rem;
  color: var(--text-muted);
  font-size: 1.05rem;
  line-height: 1.7;
}
.hero-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 2.5rem;
}
.hero-features-bar {
  display: flex;
  justify-content: center;
  gap: 2rem;
  flex-wrap: wrap;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border-color);
  color: var(--text-muted);
  font-size: 0.9rem;
}
.hero-feature-item {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

/* 区块通用样式 */
.section {
  padding: 4.5rem 0;
}
.section-alt {
  background-color: rgba(30, 41, 59, 0.4);
}
.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 3rem;
}
.section-tag {
  color: #38bdf8;
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  display: block;
  margin-bottom: 0.5rem;
}
.section-title {
  font-size: 2rem;
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 0.75rem;
}
.section-desc {
  color: var(--text-muted);
  font-size: 1rem;
}

/* 核心优势卡片网格 (3张图文卡片) */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.75rem;
}
.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 2rem;
  transition: transform 0.2s ease, border-color 0.2s ease;
  display: flex;
  flex-direction: column;
}
.feature-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary);
}
.card-icon-wrap {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-sm);
  background: rgba(2, 132, 199, 0.15);
  color: #38bdf8;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 1.25rem;
}
.feature-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 0.75rem;
}
.feature-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* 流媒体与 AI 支持图卡 */
.support-section {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
}
.support-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 2.25rem;
}
.support-card h3 {
  font-size: 1.35rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.support-card p {
  color: var(--text-muted);
  margin-bottom: 1.5rem;
  font-size: 0.95rem;
}
.badge-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
}
.chip {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border-color);
  color: #cbd5e1;
  padding: 0.4rem 0.85rem;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}
.chip.active-chip {
  border-color: rgba(56, 189, 248, 0.4);
  color: #38bdf8;
  background: rgba(56, 189, 248, 0.1);
}

/* 套餐价格对比表 */
.pricing-wrapper {
  overflow-x: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  background: var(--bg-card);
}
.pricing-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.95rem;
}
.pricing-table caption {
  padding: 1rem 1.5rem;
  text-align: left;
  font-size: 0.85rem;
  color: var(--text-muted);
  background: rgba(0, 0, 0, 0.2);
  border-bottom: 1px solid var(--border-color);
}
.pricing-table th, .pricing-table td {
  padding: 1.15rem 1.5rem;
  border-bottom: 1px solid var(--border-color);
}
.pricing-table thead th {
  background: rgba(15, 23, 42, 0.8);
  color: #ffffff;
  font-weight: 700;
  font-size: 1rem;
}
.pricing-table tbody tr:hover {
  background: rgba(255, 255, 255, 0.02);
}
.pricing-table tbody tr.popular-row {
  background: rgba(2, 132, 199, 0.08);
}
.pricing-badge {
  background: var(--cta-color);
  color: #ffffff;
  font-size: 0.7rem;
  padding: 0.15rem 0.4rem;
  border-radius: var(--radius-sm);
  font-weight: 700;
  margin-left: 0.4rem;
}
.price-value {
  font-size: 1.4rem;
  font-weight: 800;
  color: #38bdf8;
}
.price-unit {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: normal;
}

/* 用户真实评价卡片 */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}
.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}
.review-stars {
  color: #f59e0b;
  margin-bottom: 0.75rem;
  font-size: 1.1rem;
  letter-spacing: 2px;
}
.review-text {
  color: #cbd5e1;
  font-size: 0.95rem;
  line-height: 1.6;
  margin-bottom: 1.25rem;
}
.review-author {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border-color);
}
.author-avatar {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  background: var(--accent-gradient);
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.9rem;
}
.author-info h4 {
  font-size: 0.9rem;
  color: #ffffff;
}
.author-info span {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* FAQ 常见问题 (原生 details / summary, 默认 open) */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  max-width: 860px;
  margin: 0 auto;
}
.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color 0.2s ease;
}
.faq-item[open] {
  border-color: var(--primary);
}
.faq-summary {
  padding: 1.25rem 1.5rem;
  font-weight: 700;
  font-size: 1.05rem;
  color: #ffffff;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  list-style: none;
  min-height: 44px;
}
.faq-summary::-webkit-details-marker {
  display: none;
}
.faq-summary::after {
  content: "▾";
  font-size: 1.2rem;
  color: #38bdf8;
  transition: transform 0.2s ease;
}
.faq-item[open] .faq-summary::after {
  transform: rotate(180deg);
}
.faq-summary:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: -2px;
}
.faq-content {
  padding: 0 1.5rem 1.25rem;
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.7;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  padding-top: 1rem;
}
.faq-content a {
  color: #38bdf8;
  text-decoration: underline;
  text-underline-offset: 3px;
}
.faq-content a:hover {
  color: #ffffff;
}

/* 知识科普聚合页 & 9 篇文章专属样式 */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.75rem;
}
.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all 0.2s ease;
}
.article-card:hover {
  border-color: var(--primary);
  transform: translateY(-3px);
}
.article-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}
.article-badge {
  background: rgba(2, 132, 199, 0.15);
  color: #38bdf8;
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
}
.article-card h3 {
  font-size: 1.15rem;
  line-height: 1.4;
  margin-bottom: 0.75rem;
}
.article-card h3 a {
  color: #ffffff;
  text-decoration: none;
}
.article-card h3 a:hover {
  color: #38bdf8;
}
.article-summary {
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1.6;
  margin-bottom: 1.25rem;
}

/* 单篇文章阅读页样式 */
.article-container {
  max-width: 820px;
  margin: 2rem auto 4rem;
  padding: 0 1.5rem;
}
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}
.breadcrumb a {
  color: #38bdf8;
  text-decoration: none;
}
.breadcrumb a:hover {
  text-decoration: underline;
}
.article-header {
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-color);
}
.article-header h1 {
  font-size: 2.25rem;
  line-height: 1.3;
  color: #ffffff;
  margin-bottom: 1rem;
}
.article-info-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}
.article-body {
  font-size: 1.05rem;
  line-height: 1.8;
  color: #cbd5e1;
}
.article-body h2 {
  font-size: 1.5rem;
  color: #ffffff;
  margin: 2rem 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-color);
}
.article-body h3 {
  font-size: 1.25rem;
  color: #ffffff;
  margin: 1.5rem 0 0.75rem;
}
.article-body p {
  margin-bottom: 1.25rem;
}
.article-body ul, .article-body ol {
  margin: 1rem 0 1.5rem 1.5rem;
}
.article-body li {
  margin-bottom: 0.5rem;
}
.article-body blockquote {
  border-left: 4px solid var(--primary);
  background: rgba(2, 132, 199, 0.1);
  padding: 1rem 1.25rem;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 1.5rem 0;
  color: #e2e8f0;
}
.article-body a {
  color: #38bdf8;
  text-decoration: underline;
  text-underline-offset: 3px;
}
.article-cta-box {
  background: linear-gradient(135deg, rgba(2, 132, 199, 0.15) 0%, rgba(37, 99, 235, 0.15) 100%);
  border: 1px solid rgba(56, 189, 248, 0.3);
  border-radius: var(--radius-md);
  padding: 2rem;
  text-align: center;
  margin: 3rem 0;
}
.article-cta-box h3 {
  font-size: 1.35rem;
  color: #ffffff;
  margin-bottom: 0.75rem;
}
.article-cta-box p {
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

/* 网站地图与独立页脚页内容容器 */
.page-content-box {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 2.5rem;
  margin: 2rem 0 4rem;
}
.page-content-box h2 {
  font-size: 1.45rem;
  color: #ffffff;
  margin: 1.75rem 0 0.75rem;
}
.page-content-box p {
  color: #cbd5e1;
  margin-bottom: 1rem;
  line-height: 1.7;
}
.page-content-box ul {
  margin: 0.75rem 0 1.5rem 1.5rem;
  color: #cbd5e1;
}
.page-content-box li {
  margin-bottom: 0.4rem;
}
.sitemap-columns {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
  margin-top: 1.5rem;
}
.sitemap-group {
  background: rgba(15, 23, 42, 0.6);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 1.5rem;
}
.sitemap-group h3 {
  font-size: 1.15rem;
  color: #38bdf8;
  margin-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.5rem;
}
.sitemap-group ul {
  list-style: none;
  margin: 0;
  padding: 0;
}
.sitemap-group li {
  margin-bottom: 0.65rem;
}
.sitemap-group a {
  color: #e2e8f0;
  text-decoration: none;
  display: inline-block;
  padding: 0.2rem 0;
  transition: color 0.2s ease;
}
.sitemap-group a:hover {
  color: #38bdf8;
  text-decoration: underline;
}

/* 页脚：严格只保留 4 个跳转新页面的独立标题链接 */
.site-footer {
  margin-top: auto;
  background-color: #0b1120;
  border-top: 1px solid var(--border-color);
  padding: 2.5rem 0 2rem;
  text-align: center;
}
.footer-links-bar {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 2rem;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}
.footer-link-item {
  color: #cbd5e1;
  text-decoration: none;
  font-size: 1rem;
  font-weight: 600;
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-sm);
  transition: all 0.2s ease;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}
.footer-link-item:hover, .footer-link-item:focus-visible {
  color: #38bdf8;
  background: rgba(255, 255, 255, 0.05);
}
.footer-divider {
  color: var(--border-light);
  user-select: none;
}
.footer-copy {
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* ==========================================================================
   响应式媒体查询 (@media) - 确保手机端 360/390/768 完美单栏，无横向溢出
   ========================================================================== */

@media (max-width: 992px) {
  .features-grid, .reviews-grid, .articles-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .hero-title {
    font-size: 2.25rem;
  }
}

@media (max-width: 768px) {
  :root {
    --header-height: 64px;
  }
  .site-header {
    height: auto;
    padding: 0.75rem 0;
  }
  .header-inner {
    flex-direction: column;
    gap: 0.75rem;
  }
  .main-nav {
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.75rem;
    font-size: 0.85rem;
  }
  .hero-section {
    padding: 2.5rem 0 2rem;
  }
  .hero-title {
    font-size: 1.85rem;
  }
  .hero-subtitle {
    font-size: 1.15rem;
  }
  .hero-features-bar {
    gap: 1rem;
  }
  .features-grid, .support-section, .reviews-grid, .articles-grid, .sitemap-columns {
    grid-template-columns: 1fr;
  }
  .section {
    padding: 3rem 0;
  }
  .section-title {
    font-size: 1.6rem;
  }
  .btn-lg {
    width: 100%;
  }
  .hero-actions {
    flex-direction: column;
    width: 100%;
  }
  .footer-links-bar {
    gap: 1rem;
    flex-direction: column;
  }
  .footer-divider {
    display: none;
  }
  .pricing-table th, .pricing-table td {
    padding: 0.85rem 0.75rem;
    font-size: 0.85rem;
  }
}

/* 用户偏好：减少动画模式 */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}