/* DataHand 官网样式 — 统一视觉系统 */
:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --accent: #06b6d4;
  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --text: #1e293b;
  --muted: #64748b;
  --border: #e2e8f0;
  --card: #ffffff;
  --success: #16a34a;
  --warning: #f59e0b;
  --radius: 14px;
  --shadow: 0 4px 24px rgba(15, 23, 42, .08);
  --shadow-lg: 0 12px 40px rgba(15, 23, 42, .12);
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", 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); }
.container { max-width: 1180px; margin: 0 auto; padding: 0 24px; }

/* 导航 */
.nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,.92); backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.logo { display: flex; align-items: center; gap: 10px; font-size: 20px; font-weight: 800; color: var(--text); }
.logo .mark {
  width: 34px; height: 34px; border-radius: 9px; display: grid; place-items: center;
  background: linear-gradient(135deg, var(--primary), var(--accent)); color: #fff; font-size: 18px;
}
.logo .mark-img { width: 34px; height: 34px; display: block; border-radius: 9px; }
.nav-links { display: flex; align-items: center; gap: 6px; }
.nav-links a {
  padding: 8px 14px; border-radius: 8px; color: var(--muted); font-size: 15px; font-weight: 500;
}
.nav-links a:hover { background: var(--bg-alt); color: var(--primary); }
.nav-links a.active { color: var(--primary); background: #eff6ff; }
.nav-cta {
  padding: 9px 18px; border-radius: 9px; font-size: 15px; font-weight: 600;
  background: var(--primary); color: #fff !important;
}
.nav-cta:hover { background: var(--primary-dark); }

/* Hero */
.hero {
  padding: 88px 0 72px; text-align: center;
  background: linear-gradient(180deg, #f0f7ff 0%, #ffffff 100%);
}
.hero h1 { font-size: 50px; font-weight: 800; line-height: 1.2; letter-spacing: -.5px; }
.hero h1 .grad {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero .sub { font-size: 19px; color: var(--muted); margin: 20px auto 0; max-width: 720px; }
.hero .actions { margin-top: 34px; display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.hero .meta { margin-top: 22px; color: var(--muted); font-size: 14px; }
.badges { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; margin-top: 26px; }
.badge {
  background: #fff; border: 1px solid var(--border); border-radius: 999px;
  padding: 6px 14px; font-size: 13px; color: var(--muted);
}

/* 按钮 */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 13px 28px; border-radius: 10px; font-size: 16px; font-weight: 600;
  border: 1px solid transparent; cursor: pointer; transition: all .18s;
}
.btn-primary { background: var(--primary); color: #fff; box-shadow: 0 4px 14px rgba(37,99,235,.28); }
.btn-primary:hover { background: var(--primary-dark); color: #fff; transform: translateY(-1px); }
.btn-ghost { background: #fff; color: var(--text); border-color: var(--border); }
.btn-ghost:hover { border-color: var(--primary); color: var(--primary); }
.btn-lg { padding: 16px 36px; font-size: 17px; }

/* 区块 */
section { padding: 72px 0; }
section.alt { background: var(--bg-alt); }
.section-head { text-align: center; max-width: 720px; margin: 0 auto 48px; }
.section-head h2 { font-size: 34px; font-weight: 800; margin-bottom: 12px; }
.section-head p { color: var(--muted); font-size: 16px; }

/* 卡片网格 */
.grid { display: grid; gap: 22px; }
.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: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 26px; transition: all .2s;
}
.card:hover { box-shadow: var(--shadow); transform: translateY(-2px); border-color: #cbd5e1; }
.card .icon {
  width: 46px; height: 46px; border-radius: 12px; display: grid; place-items: center;
  font-size: 22px; margin-bottom: 16px;
  background: #eff6ff;
}
.card h3 { font-size: 18px; font-weight: 700; margin-bottom: 8px; }
.card p { color: var(--muted); font-size: 14.5px; }

/* 统计 */
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; text-align: center; }
.stat .num {
  font-size: 38px; font-weight: 800;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.stat .label { color: var(--muted); font-size: 14px; margin-top: 4px; }

/* 定价 */
.price-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; align-items: start; }
.price-card {
  background: #fff; border: 1.5px solid var(--border); border-radius: 18px; padding: 32px;
  position: relative;
}
.price-card.featured { border-color: var(--primary); box-shadow: var(--shadow-lg); transform: scale(1.03); }
.price-card .tag {
  position: absolute; top: -13px; left: 50%; transform: translateX(-50%);
  background: var(--primary); color: #fff; font-size: 12.5px; font-weight: 600;
  padding: 5px 14px; border-radius: 999px;
}
.price-card h3 { font-size: 20px; margin-bottom: 6px; }
.price-card .desc { color: var(--muted); font-size: 14px; min-height: 42px; }
.price-card .amount { font-size: 40px; font-weight: 800; margin: 18px 0 4px; color: var(--primary); }
.price-card .amount small { font-size: 15px; font-weight: 500; color: var(--muted); }
.price-card ul { list-style: none; margin: 22px 0; }
.price-card li { padding: 8px 0 8px 26px; position: relative; font-size: 14.5px; }
.price-card li::before { content: "✓"; position: absolute; left: 0; color: var(--success); font-weight: 700; }
.price-card .btn { width: 100%; justify-content: center; }

/* 表格 */
table { width: 100%; border-collapse: collapse; background: #fff; border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); }
th, td { padding: 13px 18px; text-align: left; font-size: 14.5px; border-bottom: 1px solid var(--border); }
th { background: var(--primary); color: #fff; font-weight: 600; }
tr:last-child td { border-bottom: none; }
tr:nth-child(even) td { background: var(--bg-alt); }

/* 代码块 */
pre {
  background: #0f172a; color: #e2e8f0; padding: 18px 20px; border-radius: 12px;
  overflow-x: auto; font-size: 13.5px; line-height: 1.6;
  font-family: "Cascadia Code", Consolas, monospace;
}
code { font-family: "Cascadia Code", Consolas, monospace; font-size: .92em; }
p code, li code { background: #eff6ff; color: var(--primary-dark); padding: 2px 6px; border-radius: 5px; }

/* 文档布局 */
.doc-layout { display: grid; grid-template-columns: 240px 1fr; gap: 40px; padding: 40px 0 80px; }
.doc-side { position: sticky; top: 92px; align-self: start; }
.doc-side h4 { font-size: 13px; text-transform: uppercase; color: var(--muted); margin: 18px 0 8px; letter-spacing: .5px; }
.doc-side a { display: block; padding: 7px 12px; border-radius: 8px; color: var(--muted); font-size: 14.5px; }
.doc-side a:hover { background: var(--bg-alt); color: var(--primary); }
.doc-side a.active { background: #eff6ff; color: var(--primary); font-weight: 600; }
.doc-body h1 { font-size: 32px; margin-bottom: 10px; }
.doc-body h2 { font-size: 23px; margin: 38px 0 14px; padding-bottom: 8px; border-bottom: 1px solid var(--border); }
.doc-body h3 { font-size: 18px; margin: 26px 0 10px; }
.doc-body p { margin: 12px 0; color: #334155; }
.doc-body ul, .doc-body ol { margin: 12px 0 12px 24px; }
.doc-body li { margin: 7px 0; }
.doc-body blockquote {
  border-left: 4px solid var(--primary); background: #f0f7ff;
  padding: 12px 18px; border-radius: 0 8px 8px 0; margin: 16px 0; color: #334155;
}

/* 提示框 */
.alert { padding: 14px 18px; border-radius: 10px; margin: 16px 0; font-size: 14.5px; }
.alert-info { background: #eff6ff; border-left: 4px solid var(--primary); }
.alert-warn { background: #fffbeb; border-left: 4px solid var(--warning); }
.alert-ok { background: #f0fdf4; border-left: 4px solid var(--success); }

/* 步骤 */
.steps { counter-reset: step; }
.step { position: relative; padding: 0 0 26px 54px; }
.step::before {
  counter-increment: step; content: counter(step);
  position: absolute; left: 0; top: 0; width: 34px; height: 34px; border-radius: 50%;
  background: var(--primary); color: #fff; display: grid; place-items: center;
  font-weight: 700; font-size: 15px;
}
.step:not(:last-child)::after {
  content: ""; position: absolute; left: 16px; top: 38px; bottom: 4px; width: 2px; background: var(--border);
}
.step h3 { font-size: 17px; margin-bottom: 4px; }
.step p { color: var(--muted); font-size: 14.5px; }

/* FAQ */
.faq-item { border-bottom: 1px solid var(--border); }
.faq-q {
  padding: 18px 0; font-size: 16.5px; font-weight: 600; cursor: pointer;
  display: flex; justify-content: space-between; align-items: center;
}
.faq-q::after { content: "+"; font-size: 22px; color: var(--muted); font-weight: 400; }
.faq-item.open .faq-q::after { content: "−"; }
.faq-a { display: none; padding: 0 0 20px; color: var(--muted); font-size: 15px; }
.faq-item.open .faq-a { display: block; }

/* 页脚 */
footer { background: #0f172a; color: #94a3b8; padding: 54px 0 30px; margin-top: 40px; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 36px; }
footer h5 { color: #fff; font-size: 14.5px; margin-bottom: 14px; }
footer a { display: block; color: #94a3b8; font-size: 14px; padding: 5px 0; }
footer a:hover { color: #fff; }
.footer-bottom {
  border-top: 1px solid #1e293b; margin-top: 36px; padding-top: 22px;
  text-align: center; font-size: 13px; color: #64748b;
}

/* 响应式 */
@media (max-width: 900px) {
  .grid-3, .grid-4, .price-grid, .stats, .footer-grid { grid-template-columns: 1fr 1fr; }
  .grid-2 { grid-template-columns: 1fr; }
  .doc-layout { grid-template-columns: 1fr; }
  .doc-side { position: static; }
  .hero h1 { font-size: 34px; }
  .nav-links { display: none; }
}
@media (max-width: 620px) {
  .grid-3, .grid-4, .price-grid, .stats, .footer-grid { grid-template-columns: 1fr; }
  .hero { padding: 56px 0 44px; }
  .hero h1 { font-size: 28px; }
  .price-card.featured { transform: none; }
}