/* ==========================================================================
   大哥云 (Dageyun) 浅色高品质原生 CSS 样式表
   极简·超快·自适应响应式布局
   ========================================================================== */

:root {
  /* 浅色主题色彩系统 */
  --bg-main: #f8fafc;
  --bg-card: #ffffff;
  --bg-alt: #f1f5f9;
  --bg-accent-light: #eff6ff;
  
  --text-main: #0f172a;
  --text-muted: #475569;
  --text-light: #64748b;
  
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-gradient: linear-gradient(135deg, #2563eb 0%, #0891b2 100%);
  --accent-cyan: #06b6d4;
  --accent-green: #10b981;
  --accent-orange: #f59e0b;
  
  --border-color: #e2e8f0;
  --border-hover: #cbd5e1;
  
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px rgba(15, 23, 42, 0.06);
  --shadow-lg: 0 12px 32px rgba(37, 99, 235, 0.12);
  --shadow-card-hover: 0 16px 36px rgba(37, 99, 235, 0.15);
  
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-xl: 24px;
  
  --max-width: 1200px;
  --header-height: 72px;
}

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

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
  overflow-x: hidden;
}

/* 容器与布局 */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

section {
  padding: 80px 0;
}

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

/* 统一按钮样式 (支持移动端手指触控，高度 >= 48px) */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 28px;
  min-height: 48px;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
  border: none;
  white-space: nowrap;
}

.btn-primary {
  background: var(--primary-gradient);
  color: #ffffff !important;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.35);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.45);
}

.btn-secondary {
  background-color: var(--bg-card);
  color: var(--primary) !important;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
  background-color: var(--bg-accent-light);
  border-color: var(--primary);
  transform: translateY(-2px);
}

.btn-lg {
  padding: 16px 36px;
  font-size: 1.125rem;
  border-radius: var(--radius-lg);
}

.btn-full {
  width: 100%;
}

/* 统一标题与副标题 */
.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 56px auto;
}

.badge-tag {
  display: inline-block;
  padding: 6px 14px;
  background-color: var(--bg-accent-light);
  color: var(--primary);
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: 50px;
  margin-bottom: 16px;
  border: 1px solid rgba(37, 99, 235, 0.15);
}

.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.02em;
  line-height: 1.25;
  margin-bottom: 16px;
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--text-muted);
}

/* 顶部导航栏 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: rgba(255, 255, 255, 0.9);
  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-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-main);
  text-decoration: none;
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: var(--primary-gradient);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 1.2rem;
  font-weight: 900;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.95rem;
  transition: color 0.2s ease;
}

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

.nav-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

/* 主视觉区 Hero */
.hero {
  padding: 90px 0 100px 0;
  background: radial-gradient(circle at 50% 0%, rgba(37, 99, 235, 0.08) 0%, rgba(248, 250, 252, 0) 70%);
  text-align: center;
}

.hero-content {
  max-width: 860px;
  margin: 0 auto;
}

.hero-title {
  font-size: 3.25rem;
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin-bottom: 24px;
  color: var(--text-main);
}

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

.hero-description {
  font-size: 1.25rem;
  color: var(--text-muted);
  margin-bottom: 40px;
  line-height: 1.7;
}

.hero-cta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 48px;
}

.hero-highlights {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 28px;
  flex-wrap: wrap;
  font-size: 0.925rem;
  color: var(--text-muted);
}

.highlight-item {
  display: flex;
  align-items: center;
  gap: 8px;
}

.check-icon {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background-color: var(--accent-green);
  color: white;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: bold;
}

/* 核心优势网格 */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow-sm);
  transition: all 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(37, 99, 235, 0.3);
}

.feature-icon {
  width: 52px;
  height: 52px;
  background-color: var(--bg-accent-light);
  color: var(--primary);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  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-muted);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* 流媒体与 AI 支持 */
.support-block {
  margin-bottom: 40px;
}

.support-block-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 20px;
  text-align: center;
}

.media-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 16px;
}

.media-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px 16px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: all 0.25s ease;
}

.media-card:hover {
  border-color: var(--primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.media-logo {
  font-size: 2rem;
  margin-bottom: 8px;
}

.media-name {
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--text-main);
}

/* 套餐价格对比 */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  align-items: stretch;
}

.price-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 36px 28px;
  display: flex;
  flex-direction: column;
  position: relative;
  box-shadow: var(--shadow-sm);
  transition: all 0.3s ease;
}

.price-card.popular {
  border: 2px solid var(--primary);
  box-shadow: var(--shadow-lg);
  transform: scale(1.02);
}

.price-card:hover {
  box-shadow: var(--shadow-card-hover);
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--primary-gradient);
  color: white;
  padding: 4px 16px;
  border-radius: 50px;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.price-header {
  margin-bottom: 24px;
}

.price-name {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 8px;
}

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

.price-amount-box {
  margin-bottom: 28px;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.price-currency {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary);
}

.price-amount {
  font-size: 2.75rem;
  font-weight: 900;
  color: var(--text-main);
  line-height: 1;
}

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

.price-features {
  list-style: none;
  margin-bottom: 32px;
  flex-grow: 1;
}

.price-features li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.925rem;
  color: var(--text-muted);
  margin-bottom: 12px;
}

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

/* FAQ 免 JS Accordion */
.faq-list {
  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);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: border-color 0.2s ease;
}

.faq-item:hover {
  border-color: var(--border-hover);
}

.faq-item summary {
  padding: 20px 24px;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-main);
  cursor: pointer;
  user-select: none;
  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: 1.4rem;
  color: var(--primary);
  font-weight: 400;
  transition: transform 0.25s ease;
}

.faq-item[open] summary::after {
  content: "−";
}

.faq-answer {
  padding: 0 24px 20px 24px;
  color: var(--text-muted);
  font-size: 0.975rem;
  line-height: 1.7;
  border-top: 1px dashed var(--border-color);
  padding-top: 16px;
}

/* 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-lg);
  padding: 28px;
  box-shadow: var(--shadow-sm);
}

.stars {
  color: var(--accent-orange);
  font-size: 1.1rem;
  margin-bottom: 12px;
}

.review-text {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 20px;
  line-height: 1.6;
}

.user-info {
  display: flex;
  align-items: center;
  gap: 12px;
}

.avatar-placeholder {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: var(--primary-gradient);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1rem;
}

.user-detail h4 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-main);
}

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

/* 底部极简 Footer：只保留四个独立标题链接 */
.site-footer {
  background-color: #ffffff;
  border-top: 1px solid var(--border-color);
  padding: 40px 0;
  text-align: center;
}

.footer-nav-only {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 40px;
  list-style: none;
  margin-bottom: 24px;
}

.footer-nav-only a {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-main);
  text-decoration: none;
  transition: color 0.2s ease;
  padding: 8px 12px;
}

.footer-nav-only a:hover {
  color: var(--primary);
  text-decoration: underline;
}

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

/* 子页面内容专用样式 */
.subpage-content {
  padding: 60px 0 100px 0;
}

.page-header-box {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 40px;
  margin-bottom: 40px;
  box-shadow: var(--shadow-sm);
}

.page-title {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 12px;
}

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

.content-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px;
  margin-bottom: 28px;
  box-shadow: var(--shadow-sm);
}

.content-card h2 {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--bg-accent-light);
}

.content-card p {
  color: var(--text-muted);
  line-height: 1.8;
  margin-bottom: 16px;
  font-size: 1rem;
}

.content-card ul {
  padding-left: 20px;
  margin-bottom: 16px;
  color: var(--text-muted);
}

.content-card li {
  margin-bottom: 8px;
  line-height: 1.6;
}

/* 网站地图层级 */
.sitemap-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}

.sitemap-card ul {
  list-style: none;
  padding-left: 0;
}

.sitemap-card li {
  margin-bottom: 12px;
}

.sitemap-card a {
  color: var(--primary);
  font-weight: 600;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.sitemap-card a:hover {
  text-decoration: underline;
}

/* ==========================================================================
   响应式媒体查询适配 (@media)
   完美兼容手机单栏显示与触摸体验
   ========================================================================== */

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

  .media-grid {
    grid-template-columns: repeat(3, 1fr);
  }

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

  .price-card.popular {
    transform: none;
  }
}

@media (max-width: 768px) {
  section {
    padding: 50px 0;
  }

  .site-header {
    height: 64px;
  }

  .nav-links {
    display: none; /* 移动端隐藏冗余顶部导航，保留简洁直达按钮 */
  }

  .hero {
    padding: 50px 0 60px 0;
  }

  .hero-title {
    font-size: 2.15rem;
  }

  .hero-description {
    font-size: 1rem;
    margin-bottom: 28px;
  }

  .hero-cta {
    flex-direction: column;
    width: 100%;
    gap: 12px;
  }

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

  .hero-highlights {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    padding-left: 20px;
  }

  .section-title {
    font-size: 1.75rem;
  }

  .features-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .media-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }

  .pricing-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .reviews-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .footer-nav-only {
    flex-direction: column;
    gap: 16px;
  }

  .sitemap-grid {
    grid-template-columns: 1fr;
  }

  .page-header-box {
    padding: 24px;
  }

  .content-card {
    padding: 24px;
  }
}

/* ==========================================================================
   高科技网格卡片 (Grid Cards) 与独立 SEO 文章页专用样式
   ========================================================================== */

.article-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  margin-top: 32px;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 28px;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-sm);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.article-card:hover {
  transform: translateY(-6px);
  border-color: rgba(37, 99, 235, 0.4);
  box-shadow: var(--shadow-lg);
}

.article-category {
  display: inline-block;
  padding: 4px 12px;
  background-color: var(--bg-accent-light);
  color: var(--primary);
  font-size: 0.8rem;
  font-weight: 700;
  border-radius: 50px;
  margin-bottom: 14px;
  align-self: flex-start;
}

.article-card-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.45;
  margin-bottom: 12px;
}

.article-card-title a {
  color: var(--text-main);
  text-decoration: none;
  transition: color 0.2s ease;
}

.article-card-title a:hover {
  color: var(--primary);
}

.article-card-desc {
  font-size: 0.925rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 20px;
  flex-grow: 1;
}

.article-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.825rem;
  color: var(--text-light);
  padding-top: 16px;
  border-top: 1px dashed var(--border-color);
}

.read-more-link {
  color: var(--primary);
  font-weight: 700;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.read-more-link:hover {
  text-decoration: underline;
}

/* 独立文章排版专用样式 */
.article-container {
  max-width: 900px;
  margin: 0 auto;
}

.article-header-box {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 40px;
  margin-bottom: 32px;
  box-shadow: var(--shadow-sm);
}

.article-page-title {
  font-size: 2.1rem;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1.3;
  margin-bottom: 16px;
}

.article-page-meta {
  display: flex;
  align-items: center;
  gap: 24px;
  color: var(--text-light);
  font-size: 0.9rem;
}

.article-content-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 44px;
  box-shadow: var(--shadow-sm);
  font-size: 1.05rem;
  line-height: 1.85;
  color: #334155;
}

.article-content-card h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-main);
  margin: 36px 0 16px 0;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--bg-accent-light);
}

.article-content-card h3 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-main);
  margin: 24px 0 12px 0;
}

.article-content-card p {
  margin-bottom: 18px;
}

.article-content-card ul, .article-content-card ol {
  padding-left: 24px;
  margin-bottom: 20px;
}

.article-content-card li {
  margin-bottom: 8px;
}

.pbn-recommend-box {
  background-color: var(--bg-accent-light);
  border: 1px solid rgba(37, 99, 235, 0.2);
  border-radius: var(--radius-md);
  padding: 24px;
  margin: 32px 0;
}

.pbn-recommend-box h4 {
  color: var(--primary);
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.pbn-recommend-box a {
  color: var(--primary);
  font-weight: 700;
  text-decoration: underline;
}

.article-bottom-bar {
  margin-top: 40px;
  padding-top: 24px;
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

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

@media (max-width: 768px) {
  .article-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  .article-content-card {
    padding: 24px;
  }
  .article-header-box {
    padding: 24px;
  }
}