/* ========================================================
   PayAI (payai.win) 现代化科技风响应式样式系统
   轻量、纯原生、全球 CDN 毫秒级秒开
   ======================================================== */

:root {
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-light: #eff6ff;
  --secondary: #0f172a;
  --accent: #10b981;
  --text-main: #1e293b;
  --text-muted: #64748b;
  --bg-page: #f8fafc;
  --bg-card: #ffffff;
  --border: #e2e8f0;
  --radius: 12px;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

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

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-page);
  color: var(--text-main);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

/* 导航栏 */
.header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 800;
  color: var(--secondary);
}

.brand-badge {
  background: linear-gradient(135deg, #2563eb, #3b82f6);
  color: #fff;
  font-size: 11px;
  padding: 2px 8px;
  border-radius: 999px;
  font-weight: 600;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  font-size: 15px;
  font-weight: 500;
  color: var(--text-muted);
}

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

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--primary);
  color: #fff !important;
  padding: 10px 20px;
  border-radius: 8px;
  font-weight: 600;
  transition: all 0.2s;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
}

.btn-primary:hover {
  background: var(--primary-hover);
  transform: translateY(-1px);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: #fff;
  color: var(--secondary) !important;
  border: 1px solid var(--border);
  padding: 10px 20px;
  border-radius: 8px;
  font-weight: 600;
  transition: all 0.2s;
}

.btn-secondary:hover {
  background: #f1f5f9;
}

/* 主视觉区 Hero */
.hero {
  max-width: 1100px;
  margin: 60px auto 40px;
  padding: 0 24px;
  text-align: center;
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--primary-light);
  color: var(--primary);
  padding: 6px 16px;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 20px;
  border: 1px solid #bfdbfe;
}

.hero-title {
  font-size: 42px;
  line-height: 1.25;
  font-weight: 800;
  color: var(--secondary);
  letter-spacing: -0.02em;
  margin-bottom: 20px;
}

.hero-desc {
  font-size: 18px;
  color: var(--text-muted);
  max-width: 780px;
  margin: 0 auto 32px;
  line-height: 1.6;
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-bottom: 48px;
  flex-wrap: wrap;
}

/* 信任指标 Trust Grid */
.trust-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
  margin-top: 30px;
}

.trust-item {
  background: #fff;
  border: 1px solid var(--border);
  padding: 20px;
  border-radius: var(--radius);
  text-align: left;
  box-shadow: var(--shadow-sm);
}

.trust-icon {
  font-size: 24px;
  margin-bottom: 10px;
}

.trust-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--secondary);
  margin-bottom: 4px;
}

.trust-text {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.5;
}

/* 容器通用类 */
.section {
  max-width: 1200px;
  margin: 60px auto;
  padding: 0 24px;
}

.section-head {
  text-align: center;
  margin-bottom: 40px;
}

.section-badge {
  font-size: 12px;
  font-weight: 700;
  color: var(--primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 8px;
  display: block;
}

.section-title {
  font-size: 30px;
  font-weight: 800;
  color: var(--secondary);
  margin-bottom: 12px;
}

.section-subtitle {
  font-size: 16px;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto;
}

/* 商品 / 服务卡片 Grid */
.products-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}

.product-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: all 0.2s;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  box-shadow: var(--shadow-sm);
}

.product-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: #cbd5e1;
}

.product-header {
  margin-bottom: 16px;
}

.product-tag {
  display: inline-block;
  font-size: 11px;
  font-weight: 700;
  padding: 3px 8px;
  border-radius: 4px;
  background: #f1f5f9;
  color: #475569;
  margin-bottom: 10px;
}

.product-name {
  font-size: 19px;
  font-weight: 700;
  color: var(--secondary);
  margin-bottom: 8px;
}

.product-desc {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.5;
  margin-bottom: 16px;
}

.product-features {
  list-style: none;
  font-size: 13px;
  color: #334155;
  margin-bottom: 24px;
}

.product-features li {
  padding: 4px 0;
  display: flex;
  align-items: center;
  gap: 6px;
}

.product-features li::before {
  content: "✓";
  color: var(--accent);
  font-weight: 800;
}

/* 文章网格 */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
}

.article-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all 0.2s;
}

.article-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: #cbd5e1;
}

.article-date {
  font-size: 12px;
  color: #94a3b8;
  margin-bottom: 8px;
}

.article-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--secondary);
  line-height: 1.4;
  margin-bottom: 12px;
}

.article-excerpt {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 20px;
  flex-grow: 1;
}

.article-link {
  font-size: 14px;
  font-weight: 600;
  color: var(--primary);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

/* 文章详情页专用排版 */
.article-page-wrap {
  max-width: 860px;
  margin: 40px auto 80px;
  padding: 0 24px;
}

.article-page-body {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px;
  box-shadow: var(--shadow-sm);
}

.article-page-body h1 {
  font-size: 30px;
  font-weight: 800;
  color: var(--secondary);
  line-height: 1.35;
  margin-bottom: 16px;
}

.article-meta {
  display: flex;
  gap: 16px;
  font-size: 13px;
  color: var(--text-muted);
  border-bottom: 1px solid var(--border);
  padding-bottom: 20px;
  margin-bottom: 28px;
}

.article-content {
  font-size: 16px;
  line-height: 1.8;
  color: #334155;
}

.article-content h2 {
  font-size: 22px;
  font-weight: 700;
  color: var(--secondary);
  margin: 36px 0 16px;
  border-bottom: 1px solid var(--border);
  padding-bottom: 8px;
}

.article-content h3 {
  font-size: 18px;
  font-weight: 600;
  color: var(--secondary);
  margin: 24px 0 12px;
}

.article-content p {
  margin-bottom: 16px;
}

.article-content ul, .article-content ol {
  margin: 0 0 20px 24px;
}

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

.article-content blockquote {
  background: #eff6ff;
  border-left: 4px solid var(--primary);
  padding: 14px 18px;
  border-radius: 4px;
  color: #1e3a8a;
  margin: 20px 0;
}

.article-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 24px 0;
  font-size: 14px;
}

.article-content th, .article-content td {
  border: 1px solid var(--border);
  padding: 12px 14px;
  text-align: left;
}

.article-content th {
  background: #f1f5f9;
  font-weight: 700;
}

/* 购买 CTA 悬浮/嵌入条 */
.cta-box {
  background: linear-gradient(135deg, #1e293b, #0f172a);
  color: #fff;
  border-radius: var(--radius);
  padding: 32px;
  margin: 40px 0;
  text-align: center;
}

.cta-box h3 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 10px;
}

.cta-box p {
  font-size: 15px;
  color: #94a3b8;
  max-width: 600px;
  margin: 0 auto 20px;
}

/* 页脚 */
.footer {
  background: #fff;
  border-top: 1px solid var(--border);
  padding: 40px 24px;
  font-size: 14px;
  color: var(--text-muted);
  text-align: center;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin-bottom: 16px;
}

/* 移动端适配 */
@media (max-width: 768px) {
  .hero-title {
    font-size: 28px;
  }
  .nav-links {
    display: none;
  }
  .article-page-body {
    padding: 24px 16px;
  }
}