/* ===== 北京知行智研科技有限公司 · 样式 v4（浅色极简 / 珊瑚橙 / 分栏） ===== */
:root {
  --ink: #0F172A;
  --accent: #FF5A3C;
  --slate: #64748B;
  --bg: #FAFBFE;
  --card: #FFFFFF;
  --line: #E7EAF0;
  --radius: 18px;
  --shadow: 0 14px 40px rgba(15,23,42,.07);
  --maxw: 1120px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", system-ui, sans-serif;
  color: var(--ink); background: var(--bg); line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
.container { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* 顶部导航 */
.site-header { background: rgba(255,255,255,.9); backdrop-filter: blur(8px); border-bottom: 1px solid var(--line); position: sticky; top: 0; z-index: 50; }
.nav { display: flex; align-items: center; justify-content: space-between; height: 74px; }
.brand { display: flex; align-items: center; gap: 12px; }
.brand img { width: 42px; height: 42px; }
.brand .name { font-weight: 800; font-size: 17px; color: var(--ink); line-height: 1.3; }
.brand .name small { display: block; font-size: 10px; color: var(--slate); letter-spacing: 1.5px; }
.nav-links { display: flex; gap: 6px; list-style: none; }
.nav-links a { padding: 9px 18px; border-radius: 999px; font-size: 15px; color: var(--ink); transition: .2s; }
.nav-links a:hover { color: var(--accent); }
.nav-links a.active { background: var(--accent); color: #fff; font-weight: 700; }
.nav-toggle { display: none; background: none; border: 0; font-size: 26px; cursor: pointer; color: var(--ink); }

/* Hero 分栏 */
.hero { padding: 84px 0 92px; }
.hero-grid { display: grid; grid-template-columns: 1.05fr .95fr; gap: 48px; align-items: center; }
.hero h1 { font-size: 44px; line-height: 1.2; margin-bottom: 16px; letter-spacing: -1px; }
.hero h1 span { color: var(--accent); }
.hero p { font-size: 18px; color: var(--slate); max-width: 520px; }
.hero .cta { margin-top: 28px; display: flex; gap: 14px; flex-wrap: wrap; }
.btn { display: inline-block; padding: 12px 28px; border-radius: 999px; font-size: 15px; font-weight: 700; transition: .2s; cursor: pointer; }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 26px rgba(255,90,60,.4); }
.btn-ghost { border: 1px solid var(--line); color: var(--ink); }
.btn-ghost:hover { background: #fff; }

/* Hero 右侧几何装饰面板 */
.hero-art { position: relative; background: linear-gradient(135deg, #0F172A, #1f2d44); border-radius: 28px; min-height: 360px; display: grid; place-items: center; overflow: hidden; box-shadow: var(--shadow); }
.hero-art img { width: 150px; height: 150px; filter: drop-shadow(0 10px 24px rgba(0,0,0,.4)); position: relative; z-index: 2; }
.hero-art .ring { position: absolute; border: 2px dashed rgba(255,90,60,.5); border-radius: 50%; }
.hero-art .r1 { width: 260px; height: 260px; }
.hero-art .r2 { width: 360px; height: 360px; }
.hero-art .dot { position: absolute; width: 14px; height: 14px; border-radius: 50%; background: var(--accent); }

/* 区块 */
.section { padding: 72px 0; }
.section-title { font-size: 28px; margin-bottom: 8px; }
.section-sub { color: var(--slate); margin-bottom: 36px; }
.eyebrow { display: inline-block; font-size: 12px; letter-spacing: 3px; color: var(--accent); font-weight: 700; margin-bottom: 10px; }

.cards { display: grid; gap: 22px; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 28px; box-shadow: var(--shadow); transition: .2s; }
.card:hover { transform: translateY(-4px); border-color: var(--accent); }
.card .ico { width: 46px; height: 46px; border-radius: 12px; background: #fff0ec; color: var(--accent); display: grid; place-items: center; margin-bottom: 16px; font-weight: 800; font-size: 20px; }
.card h3 { font-size: 19px; margin-bottom: 8px; }
.card p { color: var(--slate); font-size: 15px; }
.card ul { margin-top: 12px; color: var(--slate); font-size: 14px; padding-left: 18px; }

.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px,1fr)); gap: 16px; }
.stat { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 26px; text-align: center; }
.stat .num { font-size: 34px; font-weight: 800; color: var(--accent); }
.stat .label { color: var(--slate); font-size: 14px; margin-top: 4px; }

.list { display: grid; gap: 16px; }
.list .item { display: flex; gap: 16px; align-items: flex-start; background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px 20px; }
.list .badge { flex: 0 0 auto; width: 44px; height: 44px; border-radius: 12px; background: var(--ink); color: #fff; display: grid; place-items: center; font-weight: 800; }
.list .item h4 { font-size: 17px; margin-bottom: 4px; }
.list .item p { color: var(--slate); font-size: 15px; }

.team-grid { display: grid; gap: 22px; grid-template-columns: repeat(auto-fit, minmax(210px,1fr)); }
.member { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; text-align: center; box-shadow: var(--shadow); }
.member .avatar { width: 70px; height: 70px; margin: 0 auto 14px; border-radius: 50%; background: linear-gradient(135deg, #0F172A, var(--accent)); display: grid; place-items: center; color: #fff; font-size: 24px; font-weight: 800; }
.member h4 { font-size: 17px; }
.member .role { color: var(--accent); font-weight: 700; font-size: 14px; margin-bottom: 8px; }
.member p { color: var(--slate); font-size: 14px; }

.contact-grid { display: grid; grid-template-columns: 1.3fr 1fr; gap: 26px; }
.contact-info li { list-style: none; padding: 13px 0; border-bottom: 1px dashed var(--line); display: flex; gap: 12px; }
.contact-info li b { color: var(--ink); width: 84px; flex: 0 0 auto; }
.contact-info li span { color: var(--slate); }
.map-box { background: var(--ink); border-radius: var(--radius); min-height: 220px; display: grid; place-items: center; color: #cbd5e1; }

.footer { background: var(--ink); color: #cbd5e1; padding: 38px 0; }
.footer .container { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 16px; }
.footer a { color: #cbd5e1; text-decoration: underline; text-underline-offset: 3px; }
.footer a:hover { color: var(--accent); }
.footer .copy { font-size: 13px; color: #94a3b8; }

@media (max-width: 900px) {
  .nav-links { display: none; position: absolute; top: 74px; left: 0; right: 0; flex-direction: column; background: #fff; padding: 12px 24px; border-bottom: 1px solid var(--line); }
  .nav-links.open { display: flex; }
  .nav-toggle { display: block; }
  .hero-grid { grid-template-columns: 1fr; }
  .hero-art { min-height: 260px; order: -1; }
  .hero h1 { font-size: 34px; }
  .contact-grid { grid-template-columns: 1fr; }
}