/* ============================================================
   渐青云官网 — 全站样式（纯静态，无后端）
   字体：优先 Noto Sans SC（可商用），回退系统字体（不内嵌字体文件，无授权问题）
   ============================================================ */

:root {
  --primary: #0e7490;
  --primary-dark: #155e75;
  --accent: #06b6d4;
  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --text: #0f172a;
  --text-muted: #64748b;
  --border: #e2e8f0;
  --radius: 10px;
  --maxw: 1120px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  font-family: "Noto Sans SC", "PingFang SC", "Microsoft YaHei",
    "Hiragino Sans GB", system-ui, -apple-system, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-dark); }
img { max-width: 100%; display: block; }
.container { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* 跳过导航（可访问性） */
.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 200;
  background: var(--primary); color: #fff; padding: 8px 16px; border-radius: 0 0 6px 0;
}
.skip-link:focus { left: 0; color: #fff; }

/* 顶部导航 */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
.nav { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { display: flex; align-items: center; gap: 8px; }
.logo { width: 30px; height: 30px; flex-shrink: 0; }
.brand .name { font-size: 1.35rem; font-weight: 700; color: var(--primary-dark); }
.brand .slogan { font-size: 0.85rem; color: var(--text-muted); }
.nav-links { display: flex; gap: 24px; list-style: none; }
.nav-links a {
  color: var(--text-muted); font-size: 0.95rem; font-weight: 500;
  padding: 6px 2px; border-bottom: 2px solid transparent;
}
.nav-links a:hover { color: var(--primary); }
.nav-links a.active { color: var(--primary); border-bottom-color: var(--primary); }
.nav-toggle {
  display: none; border: none; background: none; cursor: pointer;
  font-size: 1.5rem; color: var(--text);
}

/* Hero */
.hero {
  background: linear-gradient(135deg, #164e63 0%, #0e7490 60%, #155e75 100%);
  color: #fff; text-align: center; padding: 96px 24px;
}
.hero .hero-eyebrow { font-size: 0.9rem; letter-spacing: 0.2em; opacity: 0.85; margin-bottom: 12px; }
.hero h1 { font-size: 2.5rem; font-weight: 700; margin-bottom: 16px; }
.hero .hero-sub { font-size: 1.3rem; font-weight: 600; letter-spacing: 4px; margin-bottom: 16px; opacity: 0.95; }
.hero p { font-size: 1.1rem; opacity: 0.9; max-width: 640px; margin: 0 auto 32px; }
.actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn {
  display: inline-block; padding: 12px 28px; border-radius: 999px;
  font-weight: 600; font-size: 0.95rem; transition: 0.2s;
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); color: #fff; }
.btn-light { background: #fff; color: var(--primary-dark); }
.btn-light:hover { background: #e0f2fe; color: var(--primary-dark); }
.btn-ghost { border: 1px solid rgba(255, 255, 255, 0.7); color: #fff; }
.btn-ghost:hover { background: rgba(255, 255, 255, 0.12); color: #fff; }
.btn-outline { border: 1px solid var(--primary); color: var(--primary-dark); background: transparent; }
.btn-outline:hover { background: var(--primary); color: #fff; }

/* 通用 section */
.section { padding: 72px 0; }
.section-alt { background: var(--bg-alt); }
.section-head { text-align: center; max-width: 640px; margin: 0 auto 48px; }
.section-head h2 { font-size: 1.8rem; color: var(--primary-dark); margin-bottom: 12px; }
.section-head p { color: var(--text-muted); }
.section-more { text-align: center; margin-top: 40px; }

/* 卡片网格 */
.grid { display: grid; gap: 24px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  padding: 28px; transition: 0.2s;
}
.card:hover { box-shadow: 0 8px 24px rgba(14, 116, 144, 0.10); transform: translateY(-2px); }
.card h3 { color: var(--primary-dark); font-size: 1.1rem; margin-bottom: 10px; }
.card p { color: var(--text-muted); font-size: 0.95rem; }
.card .note { font-size: 0.8rem; color: #64748b; margin-top: 4px; }
.card .tag {
  display: inline-block; font-size: 0.75rem; color: var(--primary);
  background: #ecfeff; border: 1px solid #a5f3fc; border-radius: 999px;
  padding: 2px 10px; margin-bottom: 12px;
}
.card .tag.coming-soon { color: #b45309; background: #fef3c7; border-color: #fcd34d; }

/* 服务卡 */
.service-card { text-align: center; }

/* 产品卡（软件） */
.product-card { text-align: center; }
.product-card .pinyin { color: #64748b; font-size: 0.78rem; letter-spacing: 1px; }

/* 页脚 */
.site-footer { background: #0f172a; color: #cbd5e1; padding: 56px 0 24px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
.site-footer h4 { color: #fff; font-size: 1rem; margin-bottom: 16px; }
.site-footer a { color: #94a3b8; }
.site-footer a:hover { color: #fff; }
.site-footer ul { list-style: none; }
.site-footer ul li { margin-bottom: 8px; font-size: 0.9rem; }
.footer-bottom {
  border-top: 1px solid #1e293b; padding-top: 24px;
  font-size: 0.85rem; text-align: center; color: #94a3b8;
}
.filing { display: flex; justify-content: center; gap: 20px; flex-wrap: wrap; margin-bottom: 8px; }
.filing a { color: #94a3b8; }
.filing a:hover { color: #fff; }
.ai-note { margin-top: 10px; font-size: 0.75rem; color: #64748b; }

/* 页面头部（内页） */
.page-head {
  background: var(--bg-alt); border-bottom: 1px solid var(--border);
  padding: 56px 0; text-align: center;
}
.page-head h1 { font-size: 2rem; color: var(--primary-dark); margin-bottom: 8px; }
.page-head .page-head-sub { font-size: 1.2rem; font-weight: 600; letter-spacing: 3px; color: var(--text); margin-bottom: 8px; }
.page-head p { color: var(--text-muted); }

/* 广告标识 */
.ad-badge {
  display: inline-block; font-size: 0.72rem; font-weight: 600; letter-spacing: 1px;
  color: #b45309; background: #fef3c7; border: 1px solid #fcd34d;
  border-radius: 4px; padding: 2px 10px; margin-bottom: 16px;
}

/* 文章/协议页 */
.prose { max-width: 800px; margin: 0 auto; }
.prose h2 { color: var(--primary-dark); font-size: 1.3rem; margin: 32px 0 12px; }
.prose p, .prose li { color: var(--text-muted); margin-bottom: 12px; }
.prose ul { padding-left: 24px; }

/* 联系 */
.contact-row { display: flex; gap: 12px; align-items: center; margin-bottom: 12px; }
.contact-row .label { font-weight: 600; color: var(--text); min-width: 84px; }

/* 响应式 */
@media (max-width: 900px) {
  .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .hero h1 { font-size: 1.8rem; }
  .brand .slogan { display: none; }
  .nav-links {
    display: none; position: absolute; top: 64px; left: 0; right: 0;
    background: #fff; border-bottom: 1px solid var(--border);
    flex-direction: column; padding: 16px 24px; gap: 12px;
  }
  .nav-links.open { display: flex; }
  .nav-toggle { display: block; }
}