/* ==========================================================================
   大哥云 (DageCloud) 官方落地页与通用页面样式表
   极简、极速、无外部依赖纯 CSS
   ========================================================================== */

:root {
  --bg-main: #0b0f19;
  --bg-card: #151d2a;
  --bg-card-hover: #1e293b;
  --bg-nav: rgba(11, 15, 25, 0.9);
  --primary: #3b82f6;
  --primary-hover: #2563eb;
  --accent-purple: #8b5cf6;
  --accent-cyan: #06b6d4;
  --accent-green: #10b981;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  --border-color: rgba(255, 255, 255, 0.08);
  --border-highlight: rgba(59, 130, 246, 0.3);
  --gradient-hero: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 50%, #06b6d4 100%);
  --shadow-glow: 0 0 25px rgba(59, 130, 246, 0.25);
  --shadow-card: 0 10px 30px rgba(0, 0, 0, 0.3);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --max-width: 1200px;
}

/* 基础重置 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
  font-size: 16px;
}

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

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

ul {
  list-style: none;
}

/* 布局容器 */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* 导航栏 */
.header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--bg-nav);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  padding: 16px 0;
}

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.85rem;
  font-weight: 900;
  letter-spacing: -0.5px;
  color: #ffffff;
  text-shadow: 0 2px 15px rgba(255, 255, 255, 0.3);
}

.logo-badge {
  background: var(--gradient-hero);
  color: #ffffff;
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  font-size: 1rem;
  font-weight: 800;
  border: 1px solid rgba(255, 255, 255, 0.3);
  box-shadow: 0 0 15px rgba(59, 130, 246, 0.4);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-links a {
  font-size: 1.05rem;
  font-weight: 700;
  color: #ffffff;
  transition: all 0.2s ease;
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.5);
}

.nav-links a:hover {
  color: #60a5fa;
  transform: translateY(-1px);
}

/* 通用按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-size: 1rem;
  font-weight: 600;
  padding: 12px 28px;
  border-radius: var(--radius-sm);
  transition: all 0.25s ease;
  cursor: pointer;
  border: none;
  text-align: center;
}

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

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 35px rgba(59, 130, 246, 0.45);
  opacity: 0.95;
}

.btn-outline {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  color: var(--text-main);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--primary);
  transform: translateY(-2px);
}

.btn-lg {
  padding: 16px 36px;
  font-size: 1.1rem;
  border-radius: var(--radius-md);
}

/* 主视觉区 (Hero Section) */
.hero {
  padding: 90px 0 60px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: -100px;
  left: 50%;
  transform: translateX(-50%);
  width: 600px;
  height: 400px;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.15) 0%, rgba(139, 92, 246, 0.05) 50%, transparent 70%);
  filter: blur(50px);
  z-index: -1;
  pointer-events: none;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(59, 130, 246, 0.25);
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: #ffffff;
  padding: 8px 20px;
  border-radius: 30px;
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 24px;
  box-shadow: 0 0 15px rgba(59, 130, 246, 0.3);
}

.hero h1 {
  font-size: 3.4rem;
  font-weight: 900;
  line-height: 1.25;
  margin-bottom: 20px;
  letter-spacing: -1px;
  color: #ffffff;
}

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

.hero p {
  font-size: 1.25rem;
  color: #e2e8f0;
  max-width: 760px;
  margin: 0 auto 36px;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 40px;
}

.hero-features-list {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 24px;
  color: #f1f5f9;
  font-size: 1.05rem;
  font-weight: 600;
  flex-wrap: wrap;
}

.hero-features-list span {
  display: flex;
  align-items: center;
  gap: 6px;
}

.hero-features-list span::before {
  content: "✓";
  color: var(--accent-green);
  font-weight: bold;
}

/* 模块标题与公用样式 */
.section {
  padding: 80px 0;
}

.section-bg {
  background: rgba(21, 29, 42, 0.4);
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.section-header {
  text-align: center;
  margin-bottom: 50px;
}

.section-title {
  font-size: 2.5rem;
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 12px;
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto;
}

/* 核心优势 */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 30px;
  transition: all 0.3s ease;
  position: relative;
}

.card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-highlight);
  transform: translateY(-4px);
  box-shadow: var(--shadow-card);
}

.card-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-sm);
  background: rgba(59, 130, 246, 0.1);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 20px;
  border: 1px solid rgba(59, 130, 246, 0.2);
}

.card h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 10px;
}

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

/* 流媒体与 AI 支持 */
.support-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.support-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 32px;
}

.support-card h3 {
  font-size: 1.4rem;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 20px;
}

.tag {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 8px;
}

/* 价格表格 */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px 24px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all 0.3s ease;
}

.pricing-card:hover {
  transform: translateY(-5px);
  border-color: var(--primary);
}

.pricing-card.popular {
  border: 2px solid var(--primary);
  background: linear-gradient(180deg, rgba(59, 130, 246, 0.08) 0%, var(--bg-card) 100%);
  box-shadow: var(--shadow-glow);
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--gradient-hero);
  color: #fff;
  font-size: 0.8rem;
  font-weight: 700;
  padding: 4px 16px;
  border-radius: 20px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.pricing-header h3 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.pricing-header p {
  color: var(--text-muted);
  font-size: 0.85rem;
  min-height: 40px;
}

.pricing-price {
  margin: 24px 0;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.pricing-price .currency {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--primary);
}

.pricing-price .amount {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1;
}

.pricing-price .period {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.pricing-features {
  margin-bottom: 30px;
  flex-grow: 1;
}

.pricing-features li {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.pricing-features li strong {
  color: var(--text-main);
}

.pricing-features li::before {
  content: "✓";
  color: var(--accent-green);
  font-weight: bold;
}

/* 用户评价 */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
}

.review-user {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--gradient-hero);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: #fff;
  font-size: 1.1rem;
}

.user-info h4 {
  font-size: 1rem;
  font-weight: 600;
}

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

.stars {
  color: #fbbf24;
  margin-bottom: 10px;
  font-size: 0.9rem;
}

.review-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* 常见问题 FAQ */
.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;
}

.faq-item h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 10px;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 10px;
}

.faq-item h3::before {
  content: "Q:";
  color: var(--primary);
  font-weight: 800;
}

.faq-item p {
  color: var(--text-muted);
  font-size: 0.95rem;
  padding-left: 28px;
}

/* 底部 Footer - 严格仅保留四个标题链接 */
.footer {
  background: #070a12;
  border-top: 1px solid var(--border-color);
  padding: 40px 0;
  margin-top: auto;
}

.footer-nav {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 36px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.footer-nav a {
  color: var(--text-muted);
  font-size: 1rem;
  font-weight: 500;
  transition: color 0.2s ease;
}

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

.footer-copyright {
  text-align: center;
  color: var(--text-dim);
  font-size: 0.85rem;
}

/* 辅助页面通用样式 (about, terms, privacy, sitemap) */
.page-header {
  padding: 60px 0 40px;
  background: rgba(21, 29, 42, 0.3);
  border-bottom: 1px solid var(--border-color);
  text-align: center;
}

.page-header h1 {
  font-size: 2.6rem;
  font-weight: 900;
  color: #ffffff;
  margin-bottom: 10px;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.5);
}

.page-header p {
  color: var(--text-muted);
  font-size: 1.05rem;
}

.page-content {
  padding: 60px 0;
  max-width: 900px;
  margin: 0 auto;
}

.article-box {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 40px;
  margin-bottom: 30px;
}

.article-box h2 {
  font-size: 1.5rem;
  color: var(--text-main);
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  gap: 10px;
}

.article-box p {
  color: var(--text-muted);
  margin-bottom: 16px;
  font-size: 1rem;
  line-height: 1.7;
}

.article-box ul {
  margin-bottom: 20px;
  padding-left: 20px;
}

.article-box li {
  color: var(--text-muted);
  margin-bottom: 8px;
  list-style-type: disc;
}

.article-box strong {
  color: var(--text-main);
}

.highlight-box {
  background: rgba(59, 130, 246, 0.08);
  border-left: 4px solid var(--primary);
  padding: 16px 20px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 20px 0;
}

.highlight-box p {
  color: var(--text-main);
  margin: 0;
  font-size: 0.95rem;
}

/* 网站地图样式 */
.sitemap-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.sitemap-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
}

.sitemap-card h3 {
  font-size: 1.2rem;
  color: var(--primary);
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
}

.sitemap-card ul li {
  margin-bottom: 10px;
  list-style: none;
}

.sitemap-card ul li a {
  color: var(--text-muted);
  font-size: 0.95rem;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: color 0.2s;
}

.sitemap-card ul li a:hover {
  color: var(--text-main);
}

.sitemap-card ul li a::before {
  content: "▸";
  color: var(--primary);
}

/* ==========================================================================
   响应式适配 (Mobile Responsive @media)
   ========================================================================== */

@media (max-width: 1024px) {
  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
  }
}

@media (max-width: 768px) {
  /* 导航响应式 */
  .header .container {
    flex-direction: row;
  }

  .nav-links {
    display: none; /* 移动端精简导航 */
  }

  /* Hero 响应式 */
  .hero {
    padding: 50px 0 40px;
  }

  .hero h1 {
    font-size: 2.1rem;
  }

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

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

  .hero-actions .btn {
    width: 100%;
    min-height: 48px;
  }

  /* 基础网格一律切换为单栏 */
  .grid-3, 
  .support-grid, 
  .pricing-grid, 
  .reviews-grid,
  .sitemap-grid {
    grid-template-columns: 1fr;
  }

  .section {
    padding: 50px 0;
  }

  .section-title {
    font-size: 1.7rem;
  }

  .section-subtitle {
    font-size: 0.95rem;
  }

  /* 移动端按钮触摸增强 */
  .btn {
    width: 100%;
    padding: 14px 20px;
    min-height: 48px;
    font-size: 1.05rem;
  }

  /* 价格卡片移端调整 */
  .pricing-card {
    padding: 24px 20px;
  }

  .pricing-price .amount {
    font-size: 2.2rem;
  }

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

  /* 辅助页面 */
  .article-box {
    padding: 24px 18px;
  }

  .page-header h1 {
    font-size: 1.8rem;
  }
}