:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --bg: #ffffff;
  --bg-soft: #f5f8ff;
  --text: #1e293b;
  --text-soft: #64748b;
  --border: #e2e8f0;
  --radius: 14px;
  --max-w: 1080px;
}

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

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; }

.container { max-width: var(--max-w); margin: 0 auto; padding: 0 20px; }

/* ===== 顶部导航 ===== */
.nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
.nav .container {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.logo {
  font-size: 22px; font-weight: 700; color: var(--primary);
  display: flex; align-items: center; gap: 8px;
}
.logo .box { font-size: 24px; }
.logo img { width: 30px; height: 30px; border-radius: 8px; display: block; }
.nav-links { display: flex; gap: 28px; font-size: 15px; color: var(--text-soft); }
.nav-links a:hover { color: var(--primary); }
.nav-cta {
  background: var(--primary); color: #fff; padding: 8px 20px;
  border-radius: 8px; font-size: 15px; font-weight: 500;
}
.nav-cta:hover { background: var(--primary-dark); }

/* ===== Hero ===== */
.hero {
  background: linear-gradient(180deg, #eff5ff 0%, #ffffff 100%);
  text-align: center; padding: 80px 0 70px;
}
.hero h1 {
  font-size: 42px; font-weight: 800; line-height: 1.3;
  margin-bottom: 18px;
}
.hero h1 .hl { color: var(--primary); }
.hero p.sub {
  font-size: 18px; color: var(--text-soft); max-width: 640px; margin: 0 auto 36px;
}
.btn-group { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn {
  display: inline-block; padding: 14px 36px; border-radius: 10px;
  font-size: 17px; font-weight: 600; transition: .2s;
}
.btn-primary { background: var(--primary); color: #fff; box-shadow: 0 6px 18px rgba(37,99,235,.25); }
.btn-primary:hover { background: var(--primary-dark); transform: translateY(-2px); }
.btn-ghost { border: 1.5px solid var(--border); color: var(--text); background: #fff; }
.btn-ghost:hover { border-color: var(--primary); color: var(--primary); }
.hero-meta {
  margin-top: 34px; font-size: 14px; color: var(--text-soft);
  display: flex; gap: 28px; justify-content: center; flex-wrap: wrap;
}

/* ===== 通用 Section ===== */
section { padding: 72px 0; }
.section-alt { background: var(--bg-soft); }
.sec-title { text-align: center; font-size: 30px; font-weight: 700; margin-bottom: 12px; }
.sec-desc { text-align: center; color: var(--text-soft); max-width: 620px; margin: 0 auto 48px; font-size: 16px; }

/* ===== 场景/痛点 ===== */
.pain-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.pain-card {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  padding: 28px; text-align: center;
}
.pain-card .icon { font-size: 36px; margin-bottom: 12px; }
.pain-card h3 { font-size: 18px; margin-bottom: 8px; }
.pain-card p { font-size: 14px; color: var(--text-soft); }

/* ===== 功能特性 ===== */
.feat-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.feat-card {
  background: #fff; border-radius: var(--radius); padding: 30px;
  border: 1px solid var(--border); transition: .2s;
}
.feat-card:hover { transform: translateY(-4px); box-shadow: 0 10px 30px rgba(30,58,138,.08); }
.feat-card .icon {
  width: 48px; height: 48px; border-radius: 12px; background: #eaf1ff;
  display: flex; align-items: center; justify-content: center; font-size: 24px;
  margin-bottom: 16px;
}
.feat-card h3 { font-size: 18px; margin-bottom: 8px; }
.feat-card p { font-size: 14px; color: var(--text-soft); }

/* ===== 使用步骤 ===== */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.step {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  padding: 30px; text-align: center; position: relative;
}
.step .num {
  width: 44px; height: 44px; border-radius: 50%; background: var(--primary); color: #fff;
  font-size: 20px; font-weight: 700; display: flex; align-items: center; justify-content: center;
  margin: 0 auto 16px;
}
.step h3 { font-size: 17px; margin-bottom: 6px; }
.step p { font-size: 14px; color: var(--text-soft); }

/* ===== 价格 ===== */
.price-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; max-width: 900px; margin: 0 auto; }
.price-card {
  background: #fff; border: 1.5px solid var(--border); border-radius: var(--radius);
  padding: 36px 28px; text-align: center; position: relative;
}
.price-card.hot { border-color: var(--primary); box-shadow: 0 12px 32px rgba(37,99,235,.12); }
.badge {
  position: absolute; top: -13px; left: 50%; transform: translateX(-50%);
  background: var(--primary); color: #fff; font-size: 12px;
  padding: 4px 14px; border-radius: 999px;
}
.price-card h3 { font-size: 18px; margin-bottom: 14px; }
.price-card .price { font-size: 40px; font-weight: 800; color: var(--primary); }
.price-card .price small { font-size: 15px; font-weight: 400; color: var(--text-soft); }
.price-card .origin { font-size: 13px; color: #94a3b8; text-decoration: line-through; margin-bottom: 16px; }
.price-card ul { list-style: none; margin: 18px 0 26px; font-size: 14px; color: var(--text-soft); }
.price-card ul li { padding: 6px 0; }
.btn-buy {
  display: block; width: 100%; padding: 12px 0; border-radius: 10px;
  background: var(--primary); color: #fff; font-size: 16px; font-weight: 600;
}
.btn-buy:hover { background: var(--primary-dark); }
.price-note { text-align: center; font-size: 13px; color: var(--text-soft); margin-top: 24px; }

/* ===== FAQ ===== */
.faq-list { max-width: 760px; margin: 0 auto; }
details {
  background: #fff; border: 1px solid var(--border); border-radius: 12px;
  padding: 18px 24px; margin-bottom: 14px;
}
details summary { font-size: 16px; font-weight: 600; cursor: pointer; list-style: none; }
details summary::before { content: "Q · "; color: var(--primary); font-weight: 800; }
details p { margin-top: 10px; font-size: 14px; color: var(--text-soft); }

/* ===== 底部 CTA ===== */
.cta {
  background: linear-gradient(135deg, #2563eb, #1e40af);
  color: #fff; text-align: center; border-radius: 20px;
  padding: 56px 30px; margin: 0 20px;
}
.cta h2 { font-size: 28px; margin-bottom: 12px; }
.cta p { opacity: .85; margin-bottom: 28px; }
.cta .btn { background: #fff; color: var(--primary); }

/* ===== Footer ===== */
footer { background: #0f172a; color: #94a3b8; padding: 44px 0; margin-top: 72px; font-size: 14px; }
.footer-grid { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 28px; }
.footer-grid a { color: #cbd5e1; }
.footer-grid a:hover { color: #fff; }
.footer-links { display: flex; gap: 20px; flex-wrap: wrap; }
.copyright { text-align: center; margin-top: 30px; font-size: 13px; color: #64748b; }

/* ===== 法律页 ===== */
.legal { padding: 56px 0 80px; }
.legal h1 { font-size: 30px; margin-bottom: 8px; }
.legal .update { color: var(--text-soft); font-size: 14px; margin-bottom: 36px; }
.legal h2 { font-size: 19px; margin: 30px 0 10px; }
.legal p, .legal li { font-size: 15px; color: #475569; margin-bottom: 8px; }
.legal ul { padding-left: 22px; }

/* ===== 响应式 ===== */
@media (max-width: 860px) {
  .pain-grid, .feat-grid, .steps, .price-grid { grid-template-columns: 1fr; }
  .hero h1 { font-size: 30px; }
  .nav-links { display: none; }
  section { padding: 52px 0; }
}