/* ==========================================================================
   山水云机场 (shanshuicloud.best) - 极简白主题原生样式表
   极白风格 | 原生 CSS | 零外部依赖 | 移动端完全响应式 | WCAG 4.5:1+ 对比度
   ========================================================================== */

:root {
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  
  /* 极白主题色彩定义 */
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-hover: #f8fafc;
  --bg-input: #f1f5f9;
  
  --text-main: #0f172a;
  --text-secondary: #334155;
  --text-muted: #64748b;
  
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-light: #eff6ff;
  --primary-border: #bfdbfe;
  
  --accent: #10b981;
  --accent-light: #ecfdf5;
  --accent-text: #047857;
  --warning: #f59e0b;
  --warning-light: #fef3c7;
  --warning-text: #b45309;
  
  --border-color: #e2e8f0;
  --border-hover: #cbd5e1;
  
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;
  
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05), 0 1px 2px rgba(0, 0, 0, 0.03);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 25px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
  
  --max-width: 1200px;
  --header-height: 72px;
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.6;
  scroll-behavior: smooth;
  text-rendering: optimizeLegibility;
  -webkit-text-size-adjust: 100%;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  background-color: #ffffff;
  background-image: 
    radial-gradient(circle at 50% 0%, rgba(37, 99, 235, 0.04) 0%, transparent 65%),
    radial-gradient(circle at 100% 100%, rgba(16, 185, 129, 0.03) 0%, transparent 50%);
  background-attachment: fixed;
}

/* 键盘无障碍跳过导航 */
.skip-link {
  position: absolute;
  top: -100px;
  left: 1rem;
  background: var(--primary);
  color: #ffffff;
  padding: 0.75rem 1.25rem;
  z-index: 9999;
  border-radius: var(--radius-sm);
  text-decoration: none;
  font-weight: 600;
  transition: top 0.2s ease;
}
.skip-link:focus {
  top: 1rem;
}

/* 基础排版 */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-main);
  line-height: 1.3;
  margin-bottom: 0.75rem;
  font-weight: 700;
  scroll-margin-top: calc(var(--header-height) + 20px);
}

h1 { font-size: 2.25rem; }
h2 { font-size: 1.85rem; }
h3 { font-size: 1.35rem; }
h4 { font-size: 1.15rem; }

p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

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

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

.container {
  width: 100%;
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.25rem;
  padding-right: 1.25rem;
}

/* 按钮通用规范 (手机端保证 >= 44x44px 触控区) */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  min-height: 48px;
  padding: 0.75rem 1.75rem;
  border-radius: var(--radius-full);
  font-size: 1rem;
  font-weight: 600;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.2s ease;
  border: 1px solid transparent;
  white-space: nowrap;
}
.btn:hover {
  text-decoration: none;
}

.btn-primary {
  background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.28);
}
.btn-primary:hover {
  background: linear-gradient(135deg, #1d4ed8 0%, #1e40af 100%);
  box-shadow: 0 6px 18px rgba(37, 99, 235, 0.38);
  transform: translateY(-1px);
  color: #ffffff;
}

.btn-secondary {
  background: #ffffff;
  color: var(--text-main);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
}
.btn-secondary:hover {
  background: #f8fafc;
  border-color: var(--border-hover);
  color: var(--primary);
}

.btn-success {
  background: linear-gradient(135deg, #10b981 0%, #059669 100%);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(16, 185, 129, 0.25);
}
.btn-success:hover {
  background: linear-gradient(135deg, #059669 0%, #047857 100%);
  color: #ffffff;
}

.btn-sm {
  min-height: 44px;
  padding: 0.5rem 1.25rem;
  font-size: 0.9rem;
}

/* 页眉与导航 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  height: var(--header-height);
  display: flex;
  align-items: center;
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.02em;
}
.brand-logo:hover {
  text-decoration: none;
}
.brand-logo svg {
  width: 36px;
  height: 36px;
  flex-shrink: 0;
  border-radius: 9px;
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.25);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.brand-logo:hover svg {
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.35);
}

.nav-menu {
  display: flex;
  align-items: center;
  list-style: none;
  gap: 1.5rem;
}

.nav-menu a {
  color: var(--text-secondary);
  font-size: 0.95rem;
  font-weight: 500;
  padding: 0.5rem 0.25rem;
  position: relative;
  transition: color 0.2s ease;
}
.nav-menu a:hover,
.nav-menu a.active {
  color: var(--primary);
  text-decoration: none;
}
.nav-menu a.active::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--primary);
  border-radius: 2px;
}

.nav-cta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

/* 主视觉区 Hero */
.hero-section {
  padding: 5rem 0 3.5rem;
  text-align: center;
  position: relative;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 1rem;
  border-radius: var(--radius-full);
  background: var(--primary-light);
  border: 1px solid var(--primary-border);
  color: #1d4ed8;
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
}

.hero-title {
  font-size: 2.85rem;
  line-height: 1.25;
  font-weight: 800;
  max-width: 900px;
  margin: 0 auto 1.25rem;
  color: var(--text-main);
  letter-spacing: -0.02em;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 760px;
  margin: 0 auto 2.5rem;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 2.5rem;
}

.hero-features-pill {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
  font-size: 0.9rem;
  color: var(--text-secondary);
}
.hero-features-pill span {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}
.hero-features-pill svg {
  width: 18px;
  height: 18px;
  color: var(--accent);
}

/* 通用区块排版 */
.section {
  padding: 4.5rem 0;
  border-top: 1px solid var(--border-color);
}

.section-header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto 3rem;
}
.section-tag {
  color: var(--primary);
  font-size: 0.875rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 0.5rem;
  display: block;
}
.section-title {
  font-size: 2.15rem;
  margin-bottom: 0.75rem;
  color: var(--text-main);
}
.section-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
}

/* 套餐价格对比表 */
.pricing-table-container {
  overflow-x: auto;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  background: #ffffff;
  box-shadow: var(--shadow-md);
  margin-bottom: 2rem;
}

.pricing-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  min-width: 720px;
}

.pricing-table caption {
  padding: 1rem;
  font-size: 0.95rem;
  color: var(--text-muted);
  text-align: right;
  caption-side: bottom;
}

.pricing-table th,
.pricing-table td {
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--border-color);
  vertical-align: middle;
}

.pricing-table thead th {
  background: var(--bg-secondary);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-main);
}

.pricing-table thead th.highlight {
  background: #eff6ff;
  color: #1d4ed8;
  border-top: 3px solid var(--primary);
}

.pricing-table tbody tr:hover {
  background: #f8fafc;
}

.plan-name {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.plan-badge {
  font-size: 0.75rem;
  padding: 0.15rem 0.5rem;
  border-radius: var(--radius-full);
  background: var(--accent-light);
  color: var(--accent-text);
  font-weight: 600;
}

.plan-price {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--primary);
}
.plan-price small {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 400;
}

.plan-features-list {
  list-style: none;
  font-size: 0.9rem;
  color: var(--text-secondary);
}
.plan-features-list li {
  margin-bottom: 0.35rem;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

/* 核心优势卡片 (3卡片) */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.75rem;
}

.feature-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.25rem 1.75rem;
  transition: all 0.25s ease;
  position: relative;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-sm);
}
.feature-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-hover);
  box-shadow: var(--shadow-lg);
}

.feature-icon-wrapper {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background: var(--primary-light);
  border: 1px solid var(--primary-border);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.5rem;
  color: var(--primary);
}
.feature-icon-wrapper svg {
  width: 28px;
  height: 28px;
}

.feature-card h3 {
  font-size: 1.3rem;
  margin-bottom: 0.85rem;
  color: var(--text-main);
}
.feature-card p {
  font-size: 0.95rem;
  line-height: 1.65;
  margin-bottom: 0;
  color: var(--text-secondary);
}

/* 流媒体与 AI 支持图卡 */
.media-ai-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.75rem;
}

.media-ai-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.25rem;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.media-ai-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
}

.media-tags-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 1.5rem;
}

.media-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.45rem 0.85rem;
  background: #f8fafc;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  font-size: 0.85rem;
  color: #1e293b;
  font-weight: 500;
}
.media-tag svg {
  width: 16px;
  height: 16px;
  color: var(--accent);
}

/* 用户评价 */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.review-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  box-shadow: var(--shadow-sm);
}

.review-stars {
  color: #f59e0b;
  margin-bottom: 0.75rem;
  letter-spacing: 2px;
  font-size: 1rem;
}

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

.review-author {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  border-top: 1px solid var(--border-color);
  padding-top: 1rem;
}

.author-avatar {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-full);
  background: var(--primary-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: var(--primary);
  font-size: 1rem;
}

.author-info h4 {
  font-size: 0.95rem;
  margin-bottom: 0.15rem;
  color: var(--text-main);
}
.author-info span {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* FAQ 常见问题解答 (原生 details / summary, 默认 open 展开) */
.faq-list {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.faq-item {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
  box-shadow: var(--shadow-sm);
}
.faq-item:hover {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-md);
}

.faq-question {
  padding: 1.25rem 1.5rem;
  font-size: 1.08rem;
  font-weight: 600;
  color: var(--text-main);
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  user-select: none;
}
.faq-question::-webkit-details-marker {
  display: none;
}
.faq-question::after {
  content: "▾";
  font-size: 1.25rem;
  color: var(--primary);
  transition: transform 0.2s ease;
}
.faq-item[open] .faq-question::after {
  transform: rotate(180deg);
}

.faq-answer {
  padding: 0 1.5rem 1.25rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
  border-top: 1px solid #f1f5f9;
  padding-top: 1rem;
}
.faq-answer p:last-child {
  margin-bottom: 0;
}

/* 页脚 Footer (严格只保留四个标题) */
.site-footer {
  background: #ffffff;
  border-top: 1px solid var(--border-color);
  padding: 3.5rem 0 2rem;
  margin-top: auto;
}

.footer-nav-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
  margin-bottom: 2.5rem;
  text-align: center;
}

.footer-column h3 {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
}
.footer-column h3 a {
  color: var(--text-main);
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.5rem 0;
  min-height: 44px;
}
.footer-column h3 a:hover {
  color: var(--primary);
  text-decoration: none;
}
.footer-column p {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.5;
}

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 1.5rem;
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}
.footer-bottom a {
  color: var(--text-secondary);
}

/* 文章详情页与知识科普页专属样式 */
.article-header {
  padding: 3rem 0 2rem;
  text-align: center;
}
.article-breadcrumb {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}
.article-breadcrumb a {
  color: var(--text-secondary);
}
.article-meta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.25rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 1rem;
}

.article-layout {
  max-width: 860px;
  margin: 0 auto;
  padding-bottom: 4rem;
}

.article-content {
  font-size: 1.05rem;
  line-height: 1.8;
  color: #334155;
}

.article-content h2 {
  font-size: 1.55rem;
  margin-top: 2.5rem;
  margin-bottom: 1rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-main);
}
.article-content h3 {
  font-size: 1.25rem;
  margin-top: 1.75rem;
  margin-bottom: 0.75rem;
  color: #1e293b;
}

.article-content ul,
.article-content ol {
  margin: 1rem 0 1.5rem 1.5rem;
  color: var(--text-secondary);
}
.article-content li {
  margin-bottom: 0.5rem;
}

.article-callout {
  background: var(--primary-light);
  border-left: 4px solid var(--primary);
  border-radius: var(--radius-sm);
  padding: 1.25rem 1.5rem;
  margin: 1.75rem 0;
  color: #1e40af;
}
.article-callout p:last-child {
  margin-bottom: 0;
}

.article-toc {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin: 2rem 0;
}
.article-toc h4 {
  font-size: 1.05rem;
  margin-bottom: 0.75rem;
  color: var(--text-main);
}
.article-toc ol {
  margin: 0 0 0 1.25rem;
  color: var(--text-secondary);
  font-size: 0.92rem;
}
.article-toc li {
  margin-bottom: 0.4rem;
}

.article-cta-box {
  background: linear-gradient(135deg, #eff6ff 0%, #f0fdf4 100%);
  border: 1px solid var(--primary-border);
  border-radius: var(--radius-lg);
  padding: 2.25rem;
  text-align: center;
  margin: 3rem 0;
  box-shadow: var(--shadow-sm);
}
.article-cta-box h3 {
  font-size: 1.4rem;
  margin-bottom: 0.75rem;
  color: var(--text-main);
}

/* 知识科普索引网格 (9篇SEO文章卡片) */
.articles-index-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.75rem;
  margin-top: 2rem;
}

.article-summary-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all 0.2s ease;
  box-shadow: var(--shadow-sm);
}
.article-summary-card:hover {
  transform: translateY(-3px);
  border-color: var(--border-hover);
  box-shadow: var(--shadow-md);
}

.article-card-tag {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--primary);
  text-transform: uppercase;
  margin-bottom: 0.75rem;
  display: block;
}

.article-summary-card h3 {
  font-size: 1.2rem;
  line-height: 1.4;
  margin-bottom: 0.75rem;
}
.article-summary-card h3 a {
  color: var(--text-main);
}
.article-summary-card h3 a:hover {
  color: var(--primary);
  text-decoration: none;
}

.article-card-excerpt {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 1.25rem;
  flex-grow: 1;
}

.article-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border-color);
  padding-top: 0.75rem;
}

/* ==========================================================================
   响应式媒体查询 (@media) - 确保在 360, 390, 768, 1440 完美单栏显示
   ========================================================================== */

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

@media (max-width: 768px) {
  :root {
    --header-height: 64px;
  }

  .site-header {
    height: auto;
    padding: 0.75rem 0;
  }
  
  .nav-container {
    flex-direction: column;
    gap: 0.75rem;
  }

  .nav-menu {
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.75rem 1rem;
  }

  .nav-menu a {
    min-height: 44px;
    display: inline-flex;
    align-items: center;
    padding: 0.25rem 0.5rem;
  }

  .hero-title {
    font-size: 2rem;
  }

  .hero-subtitle {
    font-size: 1.05rem;
  }

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

  .hero-actions .btn {
    width: 100%;
  }

  .features-grid,
  .media-ai-grid,
  .reviews-grid,
  .articles-index-grid,
  .footer-nav-grid {
    grid-template-columns: 1fr;
  }

  .section {
    padding: 3rem 0;
  }

  .footer-column {
    text-align: center;
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border-color);
  }
  .footer-column:last-child {
    border-bottom: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}