/* ==========================================================================
   极速云机场 - 纯原生轻量 CSS 样式表 (style.css)
   无外部框架 / 零依赖 / 秒开加载 / 深度优化无障碍与响应式
   ========================================================================== */

:root {
  --primary-color: #0d6efd;
  --primary-hover: #0b5ed7;
  --primary-light: #e7f1ff;
  --accent-color: #00d26a;
  --accent-hover: #00b85c;
  --text-main: #212529;
  --text-secondary: #495057;
  --text-muted: #6c757d;
  --bg-main: #ffffff;
  --bg-alt: #f8f9fa;
  --bg-card: #ffffff;
  --border-color: #dee2e6;
  --border-light: #e9ecef;
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --container-max: 1200px;
  --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
  --header-height: 70px;
}

/* 盒模型与重置 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-stack);
  color: var(--text-main);
  background-color: var(--bg-main);
  line-height: 1.65;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

/* 无障碍：跳至主内容 */
.skip-link {
  position: absolute;
  top: -40px;
  left: 10px;
  background: var(--primary-color);
  color: #ffffff;
  padding: 8px 16px;
  z-index: 9999;
  font-weight: 600;
  border-radius: var(--radius-sm);
  transition: top 0.2s ease;
  text-decoration: none;
}
.skip-link:focus {
  top: 10px;
}

/* 通用容器 */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 20px;
  padding-right: 20px;
}

/* 链接基础样式 */
a {
  color: var(--primary-color);
  text-decoration: none;
  transition: color 0.2s ease, background-color 0.2s ease, border-color 0.2s ease;
}
a:hover {
  color: var(--primary-hover);
  text-decoration: underline;
}
a:focus-visible, button:focus-visible {
  outline: 3px solid var(--primary-color);
  outline-offset: 2px;
}

/* 锚点滚动距离补偿 */
section[id] {
  scroll-margin-top: calc(var(--header-height) + 20px);
}

/* 导航页眉 */
.site-header {
  position: sticky;
  top: 0;
  width: 100%;
  height: var(--header-height);
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border-light);
  z-index: 1000;
  display: flex;
  align-items: center;
}
.site-header .header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}
.site-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
  text-decoration: none;
}
.site-logo:hover {
  text-decoration: none;
}
.logo-icon {
  width: 38px;
  height: 38px;
  flex-shrink: 0;
  border-radius: 8px;
  object-fit: cover;
  display: block;
}
.site-nav ul {
  display: flex;
  list-style: none;
  align-items: center;
  gap: 24px;
}
.site-nav a {
  color: var(--text-secondary);
  font-size: 0.95rem;
  font-weight: 500;
  padding: 6px 4px;
}
.site-nav a:hover {
  color: var(--primary-color);
  text-decoration: none;
}
/* 顶部导航“立即注册”按钮文字强制纯白 */
.site-nav .btn,
.site-nav .btn-primary {
  color: #ffffff !important;
  font-weight: 600;
}
.site-nav .btn:hover,
.site-nav .btn-primary:hover {
  color: #ffffff !important;
}
.nav-highlight {
  color: var(--primary-color) !important;
  font-weight: 600 !important;
}

/* CTA 按钮规范 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  min-width: 44px;
  padding: 10px 24px;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.2s ease;
  white-space: nowrap;
}
.btn:hover {
  text-decoration: none;
}
.btn-primary {
  background-color: var(--primary-color);
  color: #ffffff;
}
.btn-primary:hover {
  background-color: var(--primary-hover);
  color: #ffffff;
  box-shadow: 0 4px 12px rgba(13, 110, 253, 0.35);
}
.btn-accent {
  background-color: var(--accent-color);
  color: #ffffff;
}
.btn-accent:hover {
  background-color: var(--accent-hover);
  color: #ffffff;
  box-shadow: 0 4px 12px rgba(0, 210, 106, 0.35);
}
.btn-outline {
  background-color: transparent;
  border-color: var(--primary-color);
  color: var(--primary-color);
}
.btn-outline:hover {
  background-color: var(--primary-light);
  color: var(--primary-hover);
}
.btn-lg {
  padding: 14px 32px;
  font-size: 1.125rem;
}

/* Hero 主视觉区 (融入跑车镰刀型轮胎轨迹与冒烟特效背景) */
.hero-section {
  position: relative;
  padding: 84px 0 68px;
  background-color: #0b1120;
  background-image: 
    linear-gradient(180deg, rgba(11, 17, 32, 0.78) 0%, rgba(11, 17, 32, 0.90) 100%),
    url('hero-drift-bg.jpg');
  background-size: cover;
  background-position: center bottom;
  background-repeat: no-repeat;
  text-align: center;
  color: #ffffff;
  overflow: hidden;
}
.hero-section .hero-badge {
  display: inline-block;
  background-color: rgba(13, 110, 253, 0.25);
  border: 1px solid rgba(56, 189, 248, 0.4);
  color: #38bdf8;
  padding: 6px 18px;
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: 50px;
  margin-bottom: 22px;
  backdrop-filter: blur(4px);
}
.hero-section .hero-title {
  font-size: 2.6rem;
  font-weight: 800;
  line-height: 1.25;
  color: #ffffff;
  margin-bottom: 18px;
  letter-spacing: -0.5px;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.5);
}
.hero-section .hero-subtitle {
  font-size: 1.25rem;
  font-weight: 600;
  color: #38bdf8;
  margin-bottom: 22px;
  text-shadow: 0 1px 6px rgba(0, 0, 0, 0.4);
}
.hero-section .hero-description {
  max-width: 780px;
  margin: 0 auto 34px;
  font-size: 1.05rem;
  color: #cbd5e1;
  line-height: 1.75;
}
.hero-section .hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 34px;
}
.hero-section .btn-outline {
  border-color: #38bdf8;
  color: #38bdf8;
  background-color: rgba(15, 23, 42, 0.6);
  backdrop-filter: blur(4px);
}
.hero-section .btn-outline:hover {
  background-color: #38bdf8;
  color: #0b1120;
}
.hero-section .hero-guarantee {
  display: flex;
  justify-content: center;
  gap: 24px;
  font-size: 0.875rem;
  color: #94a3b8;
  flex-wrap: wrap;
}
.hero-section .hero-guarantee span {
  display: flex;
  align-items: center;
  gap: 6px;
}

/* 通用区块排版 */
.section {
  padding: 64px 0;
}
.section-alt {
  background-color: var(--bg-alt);
}
.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 48px;
}
.section-title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 12px;
}
.section-desc {
  font-size: 1rem;
  color: var(--text-secondary);
}

/* 核心优势卡片 (3列) */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}
.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 32px 24px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  display: flex;
  flex-direction: column;
}
.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}
.feature-icon-wrapper {
  width: 56px;
  height: 56px;
  background-color: var(--primary-light);
  color: var(--primary-color);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}
.feature-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text-main);
}
.feature-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* 流媒体与 AI 支持图卡 */
.streaming-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.stream-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 24px 20px;
  text-align: center;
  box-shadow: var(--shadow-sm);
}
.stream-icon {
  width: 48px;
  height: 48px;
  margin: 0 auto 14px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.stream-card h4 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 6px;
}
.stream-card p {
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* 套餐对比表 */
.pricing-wrapper {
  overflow-x: auto;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  background: #ffffff;
  border: 1px solid var(--border-light);
}
.pricing-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  min-width: 680px;
}
.pricing-table caption {
  font-size: 1.1rem;
  font-weight: 600;
  padding: 16px;
  text-align: left;
  background-color: var(--bg-alt);
  border-bottom: 1px solid var(--border-light);
  color: var(--text-main);
}
.pricing-table th,
.pricing-table td {
  padding: 18px 20px;
  border-bottom: 1px solid var(--border-light);
  font-size: 0.95rem;
}
.pricing-table thead th {
  background-color: #f1f5f9;
  font-weight: 700;
  color: var(--text-main);
}
.pricing-table .featured-plan {
  background-color: #f8fbff;
}
.pricing-table thead .featured-plan {
  background-color: #e7f1ff;
  color: var(--primary-color);
}
.price-tag {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--primary-color);
}
.price-unit {
  font-size: 0.875rem;
  color: var(--text-muted);
  font-weight: normal;
}

/* 用户评价区 */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sm);
}
.review-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}
.review-author {
  font-weight: 700;
  font-size: 1rem;
}
.review-stars {
  color: #ffc107;
  font-size: 1rem;
}
.review-text {
  font-size: 0.925rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* FAQ 常见问题 (原生 details / summary，默认展开) */
.faq-list {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  box-shadow: var(--shadow-sm);
}
.faq-item summary {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text-main);
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.faq-item summary::-webkit-details-marker {
  display: none;
}
.faq-item summary::after {
  content: "▾";
  font-size: 1.2rem;
  color: var(--primary-color);
  transition: transform 0.2s ease;
}
.faq-item[open] summary::after {
  transform: rotate(180deg);
}
.faq-content {
  margin-top: 14px;
  padding-top: 14px;
  border-top: 1px solid var(--border-light);
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* 转化呼吁条 Banner */
.cta-banner {
  background: linear-gradient(135deg, var(--primary-color) 0%, #084298 100%);
  color: #ffffff;
  padding: 56px 0;
  text-align: center;
}
.cta-banner h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 12px;
}
.cta-banner p {
  font-size: 1.1rem;
  margin-bottom: 24px;
  opacity: 0.9;
}
.cta-banner .btn-accent {
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
}

/* 页脚样式 (只保留4个标题) */
.site-footer {
  background-color: #111827;
  color: #9ca3af;
  padding: 40px 0 24px;
  border-top: 1px solid #1f2937;
}
.footer-nav {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 36px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}
.footer-link {
  color: #e5e7eb;
  font-size: 1rem;
  font-weight: 600;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  transition: color 0.2s ease;
}
.footer-link:hover {
  color: #ffffff;
  text-decoration: underline;
}
.footer-bottom {
  text-align: center;
  font-size: 0.85rem;
  color: #6b7280;
  border-top: 1px solid #1f2937;
  padding-top: 20px;
}

/* 文章正文与内容页样式 */
.article-container {
  max-width: 840px;
  margin: 0 auto;
  padding: 40px 20px 60px;
}
.article-header {
  margin-bottom: 32px;
  border-bottom: 1px solid var(--border-light);
  padding-bottom: 24px;
}
.article-meta {
  display: flex;
  gap: 16px;
  color: var(--text-muted);
  font-size: 0.875rem;
  margin-top: 12px;
}
.article-body {
  font-size: 1.05rem;
  line-height: 1.8;
  color: #2b3035;
}
.article-body h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin: 36px 0 16px;
  color: var(--text-main);
}
.article-body h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin: 24px 0 12px;
  color: var(--text-main);
}
.article-body p {
  margin-bottom: 18px;
}
.article-body ul, .article-body ol {
  margin: 0 0 20px 24px;
}
.article-body li {
  margin-bottom: 8px;
}
.article-body blockquote {
  border-left: 4px solid var(--primary-color);
  padding: 12px 18px;
  background-color: var(--bg-alt);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 24px 0;
  color: var(--text-secondary);
}
.article-nav-box {
  margin-top: 48px;
  padding: 24px;
  background-color: var(--bg-alt);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-light);
}

/* 知识科普目录网格 */
.knowledge-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.knowledge-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.knowledge-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}
.knowledge-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 12px;
  line-height: 1.4;
}
.knowledge-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 16px;
}
.knowledge-card .read-more {
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--primary-color);
}

/* 响应式适配 @media */
@media (max-width: 992px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .streaming-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .reviews-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .knowledge-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .site-header {
    height: auto;
    padding: 12px 0;
  }
  .site-header .header-inner {
    flex-direction: column;
    gap: 12px;
  }
  .site-nav ul {
    gap: 14px;
    flex-wrap: wrap;
    justify-content: center;
  }
  .hero-title {
    font-size: 1.85rem;
  }
  .hero-subtitle {
    font-size: 1.1rem;
  }
  .features-grid {
    grid-template-columns: 1fr;
  }
  .streaming-grid {
    grid-template-columns: 1fr;
  }
  .reviews-grid {
    grid-template-columns: 1fr;
  }
  .knowledge-grid {
    grid-template-columns: 1fr;
  }
  .footer-nav {
    flex-direction: column;
    gap: 16px;
  }
  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }
  .hero-actions .btn {
    width: 100%;
  }
}

@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;
    scroll-behavior: auto !important;
  }
}