/* 知弈 · GoSense 官网样式 —— 墨绿品牌，家长向，纯静态零依赖 */
:root {
  --green: #1B6E4F;
  --green-dark: #14573E;
  --green-soft: #E8F1EC;
  --ink: #1A1A1A;
  --paper: #F7F7F4;
  --text: #243029;
  --muted: #6B7A73;
  --line: rgba(20, 40, 30, 0.10);
  --radius: 16px;
  --shadow: 0 6px 24px rgba(20, 60, 40, 0.08);
  --maxw: 1080px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, "PingFang SC", "Microsoft YaHei", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--text);
  background: #fff;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--green-dark); text-decoration: none; }
a:hover { text-decoration: underline; }
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }

/* 顶部导航 */
.nav {
  position: sticky; top: 0; z-index: 10;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
}
.nav-inner { display: flex; align-items: center; gap: 16px; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 600; font-size: 18px; color: var(--ink); }
.brand img { width: 32px; height: 32px; border-radius: 8px; }
.brand:hover { text-decoration: none; }
.nav-links { display: flex; gap: 24px; margin-left: auto; align-items: center; }
.nav-links a:not(.btn) { color: var(--text); font-size: 15px; }
.nav-cta { margin-left: 8px; }

/* 按钮 */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  background: var(--green); color: #fff;
  padding: 12px 22px; border-radius: 999px;
  font-size: 15px; font-weight: 600; border: 0; cursor: pointer;
  transition: background .15s ease, transform .15s ease;
}
.btn:hover { background: var(--green-dark); text-decoration: none; transform: translateY(-1px); }
.btn.lg { padding: 16px 30px; font-size: 17px; }
.btn.ghost { background: transparent; color: var(--green-dark); border: 1px solid var(--green); }
.btn.ghost:hover { background: var(--green-soft); }

/* Hero */
.hero { padding: 72px 0 56px; background: linear-gradient(180deg, var(--green-soft) 0%, #fff 100%); }
.hero-grid { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 48px; align-items: center; }
.hero h1 { font-size: 44px; line-height: 1.25; margin: 0 0 18px; color: var(--ink); letter-spacing: -0.5px; }
.hero h1 .hl { color: var(--green); }
.hero p.lead { font-size: 19px; color: var(--muted); margin: 0 0 28px; }
.hero-actions { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }
.sysreq { font-size: 13px; color: var(--muted); margin-top: 14px; }
.hero-art { display: flex; justify-content: center; }
.hero-art svg { width: 100%; max-width: 360px; height: auto; filter: drop-shadow(var(--shadow)); }

/* 区块通用 */
.section { padding: 64px 0; }
.section.alt { background: var(--paper); }
.section h2 { font-size: 30px; color: var(--ink); margin: 0 0 8px; text-align: center; letter-spacing: -0.3px; }
.section .sub { text-align: center; color: var(--muted); margin: 0 auto 40px; max-width: 560px; }

/* 功能卡 */
.features { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 28px; box-shadow: var(--shadow);
}
.card .ico {
  width: 46px; height: 46px; border-radius: 12px; background: var(--green-soft);
  display: flex; align-items: center; justify-content: center; margin-bottom: 16px;
}
.card .ico svg { width: 26px; height: 26px; }
.card h3 { margin: 0 0 8px; font-size: 19px; color: var(--ink); }
.card p { margin: 0; color: var(--muted); font-size: 15px; }

/* 安装步骤 */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-top: 8px; }
.step { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 26px; }
.step .num {
  width: 34px; height: 34px; border-radius: 999px; background: var(--green); color: #fff;
  display: flex; align-items: center; justify-content: center; font-weight: 700; margin-bottom: 14px;
}
.step h4 { margin: 0 0 6px; font-size: 16px; color: var(--ink); }
.step p { margin: 0; font-size: 14px; color: var(--muted); }
.note { text-align: center; color: var(--muted); font-size: 14px; margin-top: 24px; }

/* FAQ */
.faq { max-width: 760px; margin: 0 auto; }
.faq details {
  border: 1px solid var(--line); border-radius: 12px; padding: 4px 20px; margin-bottom: 12px; background: #fff;
}
.faq summary { cursor: pointer; font-weight: 600; color: var(--ink); padding: 16px 0; list-style: none; font-size: 16px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; float: right; color: var(--green); font-size: 22px; line-height: 1; }
.faq details[open] summary::after { content: "\2212"; }
.faq details p { margin: 0 0 16px; color: var(--muted); font-size: 15px; }

/* CTA 收尾 */
.cta-band { background: var(--green); color: #fff; text-align: center; padding: 60px 24px; }
.cta-band h2 { color: #fff; font-size: 30px; margin: 0 0 10px; }
.cta-band p { color: rgba(255,255,255,0.85); margin: 0 0 26px; }
.cta-band .btn { background: #fff; color: var(--green-dark); }
.cta-band .btn:hover { background: var(--paper); }

/* 页脚 */
.footer { border-top: 1px solid var(--line); padding: 36px 0; color: var(--muted); font-size: 14px; }
.footer-inner { display: flex; align-items: center; gap: 18px; flex-wrap: wrap; justify-content: space-between; }
.footer a { color: var(--muted); }
.footer .links { display: flex; gap: 20px; flex-wrap: wrap; }

/* 法务页正文 */
.legal { padding: 56px 0 72px; }
.legal h1 { font-size: 32px; color: var(--ink); margin: 0 0 8px; }
.legal .updated { color: var(--muted); font-size: 14px; margin-bottom: 32px; }
.legal h2 { font-size: 21px; color: var(--ink); margin: 32px 0 10px; }
.legal p, .legal li { color: var(--text); font-size: 16px; }
.legal ul { padding-left: 22px; }
.back { display: inline-block; margin-bottom: 24px; font-size: 15px; }

/* 响应式 */
@media (max-width: 860px) {
  .hero-grid { grid-template-columns: 1fr; gap: 32px; }
  .hero-art { order: -1; }
  .hero h1 { font-size: 34px; }
  .features { grid-template-columns: 1fr; }
  .steps { grid-template-columns: 1fr; }
  .nav-links a:not(.nav-cta) { display: none; }
}