/* ==========================================================================
   腾讯文档官网 — 高效办公工具 仿站样式
   主色：翠绿系（差异化，区别于参考站蓝）
   ========================================================================== */

:root {
  --primary: #1b6af5;
  --primary-dark: #1554c6;
  --primary-darker: #10439e;
  --primary-light: #e8f0fe;
  --primary-border: #c9dafb;
  --accent: #4f83f0;
  --accent-light: #eef3fe;
  --bg: #f6f8f7;
  --card: #ffffff;
  --border: #e5e9e7;
  --title: #0f172a;
  --body: #334155;
  --muted: #64748b;
  --radius: 14px;
  --shadow: 0 2px 12px rgba(15, 23, 42, 0.06);
  --shadow-lg: 0 10px 32px rgba(15, 23, 42, 0.10);
  --maxw: 1160px;
}

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

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--body);
  font-size: 16px;
  line-height: 1.7;
}

a { color: var(--primary-dark); text-decoration: none; transition: color .2s; }
a:hover { color: var(--primary-darker); }
img { max-width: 100%; height: auto; display: block; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ---------- 顶部导航 ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.nav { display: flex; align-items: center; gap: 28px; height: 64px; }
.logo { display: flex; align-items: center; gap: 9px; font-size: 19px; font-weight: 700; color: var(--title); }
.logo img, .f-logo img { flex: none; }
.logo svg { flex: none; }
.logo span { color: var(--title); }
.logo em { font-style: normal; color: var(--primary); }
.nav-links { display: flex; gap: 4px; margin-left: 6px; }
.nav-links a {
  padding: 7px 14px; border-radius: 8px; color: var(--body); font-size: 15px; font-weight: 500;
}
.nav-links a:hover { background: var(--primary-light); color: var(--primary-darker); }
.nav-links a.active { color: var(--primary-dark); background: var(--primary-light); }
.nav-actions { margin-left: auto; display: flex; align-items: center; gap: 12px; }
.nav-login { color: var(--body); font-size: 15px; font-weight: 500; }
.nav-login:hover { color: var(--primary-dark); }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 11px 22px; border-radius: 10px; font-size: 15px; font-weight: 600;
  cursor: pointer; border: 1px solid transparent; transition: all .2s; white-space: nowrap;
}
.btn-primary { background: var(--primary); color: #fff; box-shadow: 0 4px 14px rgba(27,106,245,.28); }
.btn-primary:hover { background: var(--primary-dark); color: #fff; transform: translateY(-1px); }
.btn-outline { background: #fff; color: var(--primary-dark); border-color: var(--primary-border); }
.btn-outline:hover { background: var(--primary-light); color: var(--primary-darker); }
.btn-lg { padding: 14px 30px; font-size: 16px; border-radius: 12px; }
.btn-block { width: 100%; }

/* ---------- Hero ---------- */
.hero {
  background: linear-gradient(180deg, #eef3fe 0%, var(--bg) 100%);
  padding: 64px 0 56px;
}
.hero-grid { display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 48px; align-items: center; }
.hero-badge {
  display: inline-flex; align-items: center; gap: 7px; padding: 6px 14px;
  background: #fff; border: 1px solid var(--primary-border); border-radius: 999px;
  color: var(--primary-dark); font-size: 13px; font-weight: 600; margin-bottom: 20px;
}
.hero h1 {
  font-size: 42px; line-height: 1.25; color: var(--title); font-weight: 800; letter-spacing: -0.5px;
}
.hero h1 .hl { color: var(--primary); }
.hero .sub { margin-top: 18px; font-size: 18px; color: var(--muted); max-width: 520px; }
.hero-cta { display: flex; gap: 14px; margin-top: 30px; flex-wrap: wrap; }
.hero-note { margin-top: 16px; font-size: 13px; color: var(--muted); display: flex; gap: 16px; flex-wrap: wrap; }
.hero-note span::before { content: "✓"; color: var(--primary); margin-right: 5px; font-weight: 700; }

/* 右侧数据面板（差异化 hero，替代参考站产品截图） */
.hero-panel {
  background: #fff; border: 1px solid var(--border); border-radius: 18px;
  box-shadow: var(--shadow-lg); padding: 26px; position: relative;
}
.hero-panel::before {
  content: ""; position: absolute; inset: -12px; border-radius: 22px;
  background: radial-gradient(circle at 30% 20%, rgba(27,106,245,.12), transparent 60%);
  z-index: -1;
}
.panel-title { display: flex; align-items: center; justify-content: space-between; margin-bottom: 20px; }
.panel-title b { font-size: 15px; color: var(--title); }
.panel-title .dot { display: flex; gap: 6px; }
.panel-title .dot i { width: 10px; height: 10px; border-radius: 50%; display: block; }
.panel-title .dot i:nth-child(1){ background:#f87171; }
.panel-title .dot i:nth-child(2){ background:#fbbf24; }
.panel-title .dot i:nth-child(3){ background:#5b9bff; }
.stat-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.stat-card { background: var(--bg); border: 1px solid var(--border); border-radius: 12px; padding: 16px; }
.stat-card .num { font-size: 26px; font-weight: 800; color: var(--title); line-height: 1.1; }
.stat-card .num small { font-size: 14px; color: var(--primary); font-weight: 700; margin-left: 2px; }
.stat-card .lbl { font-size: 13px; color: var(--muted); margin-top: 6px; }
.doc-row {
  margin-top: 18px; background: var(--bg); border: 1px solid var(--border); border-radius: 12px; padding: 14px;
}
.doc-row .fname { font-size: 14px; font-weight: 600; color: var(--title); }
.doc-row .fmeta { font-size: 12px; color: var(--muted); margin-top: 3px; }
.progress { height: 6px; background: var(--border); border-radius: 99px; margin-top: 10px; overflow: hidden; }
.progress i { display: block; height: 100%; background: linear-gradient(90deg, var(--primary), #5b9bff); border-radius: 99px; }
.avatar-stack { display: flex; align-items: center; margin-top: 16px; }
.avatar-stack .av {
  width: 30px; height: 30px; border-radius: 50%; border: 2px solid #fff; margin-left: -8px;
  display: flex; align-items: center; justify-content: center; font-size: 12px; font-weight: 700; color: #fff;
}
.avatar-stack .av:first-child { margin-left: 0; }
.avatar-stack .txt { margin-left: 10px; font-size: 13px; color: var(--muted); }

/* ---------- 通用 section ---------- */
.section { padding: 60px 0; }
.section.alt { background: #fff; border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.sec-head { text-align: center; max-width: 640px; margin: 0 auto 40px; }
.sec-head h2 { font-size: 30px; font-weight: 800; color: var(--title); }
.sec-head p { margin-top: 12px; color: var(--muted); font-size: 16px; }
.sec-head.left { text-align: left; margin-left: 0; }

/* ---------- 功能网格 ---------- */
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.feature-card {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  padding: 26px; transition: all .25s; position: relative; overflow: hidden;
}
.feature-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: var(--primary-border); }
.feature-card .ic {
  width: 52px; height: 52px; border-radius: 13px; display: flex; align-items: center; justify-content: center;
  background: var(--primary-light); margin-bottom: 16px;
}
.feature-card h3 { font-size: 18px; color: var(--title); margin-bottom: 8px; }
.feature-card p { font-size: 14px; color: var(--muted); }

/* ---------- 步骤区 ---------- */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.step { display: flex; gap: 16px; }
.step .idx {
  flex: none; width: 42px; height: 42px; border-radius: 50%; background: var(--primary);
  color: #fff; font-weight: 800; font-size: 18px; display: flex; align-items: center; justify-content: center;
}
.step h3 { font-size: 17px; color: var(--title); }
.step p { font-size: 14px; color: var(--muted); margin-top: 6px; }

/* ---------- 场景卡 ---------- */
.scene-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 22px; }
.scene-card {
  display: flex; gap: 18px; background: #fff; border: 1px solid var(--border);
  border-radius: var(--radius); padding: 24px; align-items: flex-start;
}
.scene-card .ic { flex: none; width: 48px; height: 48px; border-radius: 12px; background: var(--accent-light); display: flex; align-items: center; justify-content: center; }
.scene-card h3 { font-size: 17px; color: var(--title); }
.scene-card p { font-size: 14px; color: var(--muted); margin-top: 6px; }

/* ---------- 下载矩阵 ---------- */
.dl-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.dl-card {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  padding: 26px; text-align: center; transition: all .25s;
}
.dl-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: var(--primary-border); }
.dl-card .ic { width: 60px; height: 60px; margin: 0 auto 16px; border-radius: 16px; background: var(--primary-light); display: flex; align-items: center; justify-content: center; }
.dl-card h3 { font-size: 17px; color: var(--title); }
.dl-card p { font-size: 13px; color: var(--muted); margin: 8px 0 16px; }
.dl-card .badge { display: inline-block; font-size: 12px; color: var(--primary-dark); background: var(--primary-light); padding: 3px 10px; border-radius: 99px; margin-bottom: 14px; }

/* ---------- 订阅套餐 ---------- */
.plan-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; align-items: stretch; }
.plan {
  background: #fff; border: 1px solid var(--border); border-radius: 18px; padding: 30px;
  display: flex; flex-direction: column; position: relative; transition: all .25s;
}
.plan:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.plan.hot { border: 2px solid var(--primary); box-shadow: 0 10px 30px rgba(27,106,245,.14); }
.plan .tag {
  position: absolute; top: -13px; left: 50%; transform: translateX(-50%);
  background: var(--primary); color: #fff; font-size: 12px; font-weight: 700; padding: 4px 14px; border-radius: 99px;
}
.plan h3 { font-size: 18px; color: var(--title); }
.plan .price { margin: 16px 0 4px; font-size: 40px; font-weight: 800; color: var(--title); line-height: 1; }
.plan .price small { font-size: 15px; font-weight: 600; color: var(--muted); }
.plan .price-unit { font-size: 14px; color: var(--muted); }
.plan ul { list-style: none; margin: 22px 0 26px; flex: 1; }
.plan ul li { padding: 8px 0; font-size: 14px; color: var(--body); display: flex; gap: 9px; align-items: flex-start; }
.plan ul li::before { content: "✓"; color: var(--primary); font-weight: 700; flex: none; }

/* ---------- FAQ ---------- */
.faq-list { max-width: 820px; margin: 0 auto; }
.faq-item { background: #fff; border: 1px solid var(--border); border-radius: 12px; margin-bottom: 14px; overflow: hidden; }
.faq-item details summary {
  padding: 18px 22px; cursor: pointer; font-weight: 600; color: var(--title); font-size: 16px;
  list-style: none; display: flex; justify-content: space-between; align-items: center;
}
.faq-item details summary::-webkit-details-marker { display: none; }
.faq-item details summary::after { content: "+"; font-size: 22px; color: var(--primary); font-weight: 400; }
.faq-item details[open] summary::after { content: "−"; }
.faq-item details .faq-a { padding: 0 22px 20px; font-size: 15px; color: var(--body); }

/* ---------- 正文 SEO 段 ---------- */
.seo-content { font-size: 15px; color: var(--body); text-align: justify; }
.seo-content p { margin-bottom: 14px; text-indent: 2em; }
.seo-content h2, .seo-content h3 { text-indent: 0; color: var(--title); margin: 22px 0 12px; }
.seo-content strong { color: var(--title); }

/* ---------- 文章页 ---------- */
.article { max-width: 820px; margin: 0 auto; }
.article-meta { color: var(--muted); font-size: 13px; margin: 14px 0 26px; display: flex; gap: 16px; flex-wrap: wrap; }
.article h2 { font-size: 22px; color: var(--title); margin: 28px 0 12px; }
.article h3 { font-size: 18px; color: var(--title); margin: 22px 0 10px; }
.article p { margin-bottom: 14px; text-align: justify; }
.article ul, .article ol { margin: 0 0 16px 22px; }
.article li { margin-bottom: 8px; }
.article strong { color: var(--title); }
.article .tip { background: var(--primary-light); border-left: 4px solid var(--primary); padding: 16px 18px; border-radius: 8px; margin: 18px 0; }

/* ---------- 面包屑 ---------- */
.breadcrumb { font-size: 13px; color: var(--muted); padding: 18px 0 0; }
.breadcrumb a { color: var(--muted); }
.breadcrumb a:hover { color: var(--primary-dark); }
.breadcrumb span { margin: 0 6px; color: var(--border); }

/* ---------- 页脚 ---------- */
.site-footer { background: var(--bg); color: var(--body); padding: 54px 0 0; margin-top: 40px; border-top: 1px solid var(--border); }
.footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 32px; }
.footer-col .f-logo { display: flex; align-items: center; gap: 8px; color: var(--title); font-size: 17px; font-weight: 700; margin-bottom: 14px; }
.footer-col p { font-size: 13px; color: var(--muted); line-height: 1.8; }
.footer-col h4 { color: var(--title); font-size: 15px; margin-bottom: 16px; }
.footer-col a { display: block; color: var(--muted); font-size: 13px; padding: 5px 0; }
.footer-col a:hover { color: var(--primary-dark); }
.footer-bottom { border-top: 1px solid var(--border); margin-top: 40px; padding: 20px 0; font-size: 12px; color: var(--muted); text-align: center; }

/* ---------- 404 ---------- */
.error-404 { text-align: center; padding: 90px 0 70px; }
.error-404 .code { font-size: 100px; font-weight: 800; color: var(--primary); line-height: 1; }
.error-404 h1 { font-size: 26px; color: var(--title); margin: 18px 0 10px; }
.error-404 p { color: var(--muted); margin-bottom: 28px; }

/* ---------- 响应式 ---------- */
@media (max-width: 768px) {
  .nav { gap: 14px; flex-wrap: wrap; height: auto; padding: 12px 0; }
  .nav-links { order: 3; width: 100%; overflow-x: auto; gap: 2px; }
  .nav-links a { white-space: nowrap; }
  .nav-actions { margin-left: auto; }
  .hero { padding: 40px 0; }
  .hero-grid { grid-template-columns: 1fr; gap: 34px; }
  .hero h1 { font-size: 30px; }
  .feature-grid, .dl-grid, .plan-grid, .steps { grid-template-columns: 1fr 1fr; }
  .scene-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .sec-head h2 { font-size: 25px; }
}
@media (max-width: 480px) {
  .feature-grid, .dl-grid, .plan-grid, .steps { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .hero h1 { font-size: 26px; }
  .btn-lg { padding: 13px 22px; }
  .hero-cta { flex-direction: column; }
  .hero-cta .btn { width: 100%; }
  body { font-size: 15px; }
  .stat-grid { grid-template-columns: 1fr; }
}