/* ===== 北京知行智研科技有限公司 · 样式 v5（新粗野主义 / 奶油黄） ===== */
:root {
  --ink: #1A1A1A;
  --accent: #FFD60A;
  --bg: #F4F1DE;
  --card: #FFFFFF;
  --line: #1A1A1A;
  --radius: 14px;
  --bd: 3px solid var(--ink);
  --shadow: 6px 6px 0 var(--ink);
  --shadow-sm: 4px 4px 0 var(--ink);
  --maxw: 1120px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Arial Black", system-ui, sans-serif;
  color: var(--ink); background: var(--bg); line-height: 1.7;
  -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: var(--bg); border-bottom: var(--bd); position: sticky; top: 0; z-index: 50; }
.nav { display: flex; align-items: center; justify-content: space-between; height: 78px; }
.brand { display: flex; align-items: center; gap: 12px; }
.brand img { width: 44px; height: 44px; }
.brand .name { font-weight: 900; font-size: 17px; color: var(--ink); line-height: 1.2; }
.brand .name small { display: block; font-size: 10px; color: #555; letter-spacing: 1.5px; }
.nav-links { display: flex; gap: 10px; list-style: none; }
.nav-links a { padding: 9px 16px; border: var(--bd); border-radius: 10px; font-size: 15px; font-weight: 700; background: #fff; transition: .15s; }
.nav-links a:hover { transform: translate(-2px,-2px); box-shadow: var(--shadow-sm); }
.nav-links a.active { background: var(--ink); color: #fff; }
.nav-toggle { display: none; background: #fff; border: var(--bd); border-radius: 10px; font-size: 22px; width: 46px; height: 46px; cursor: pointer; color: var(--ink); }

/* Hero */
.hero { padding: 64px 0 72px; }
.hero-box { background: var(--accent); border: var(--bd); border-radius: 22px; box-shadow: var(--shadow); padding: 48px; display: grid; grid-template-columns: 1.1fr .9fr; gap: 40px; align-items: center; }
.hero h1 { font-size: 46px; line-height: 1.15; margin-bottom: 18px; font-weight: 900; }
.hero h1 .hl { background: #fff; border: var(--bd); padding: 0 8px; border-radius: 8px; }
.hero p { font-size: 18px; color: #2b2b2b; max-width: 520px; font-weight: 600; }
.hero .cta { margin-top: 26px; display: flex; gap: 14px; flex-wrap: wrap; }
.btn { display: inline-block; padding: 12px 26px; border: var(--bd); border-radius: 12px; font-size: 15px; font-weight: 800; transition: .15s; cursor: pointer; background: #fff; }
.btn-primary { background: var(--ink); color: #fff; }
.btn-primary:hover { transform: translate(-2px,-2px); box-shadow: var(--shadow-sm); }
.btn-ghost { background: #fff; }
.btn-ghost:hover { transform: translate(-2px,-2px); box-shadow: var(--shadow-sm); }
.hero-art { background: #fff; border: var(--bd); border-radius: 18px; min-height: 260px; display: grid; place-items: center; box-shadow: var(--shadow-sm); }
.hero-art img { width: 150px; height: 150px; }

/* 区块 */
.section { padding: 64px 0; }
.section-title { font-size: 30px; font-weight: 900; margin-bottom: 8px; }
.section-sub { color: #444; font-weight: 600; margin-bottom: 34px; }
.tag { display: inline-block; background: var(--ink); color: #fff; font-size: 12px; font-weight: 800; letter-spacing: 2px; padding: 5px 12px; border-radius: 8px; margin-bottom: 12px; }

.cards { display: grid; gap: 22px; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); }
.card { background: var(--card); border: var(--bd); border-radius: var(--radius); padding: 26px; box-shadow: var(--shadow-sm); transition: .15s; }
.card:hover { transform: translate(-3px,-3px); box-shadow: var(--shadow); }
.card .ico { width: 46px; height: 46px; border: var(--bd); border-radius: 12px; background: var(--accent); display: grid; place-items: center; margin-bottom: 16px; font-weight: 900; font-size: 20px; }
.card h3 { font-size: 19px; font-weight: 800; margin-bottom: 8px; }
.card p { color: #444; font-size: 15px; font-weight: 500; }
.card ul { margin-top: 12px; color: #444; font-size: 14px; padding-left: 18px; font-weight: 500; }

.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px,1fr)); gap: 18px; }
.stat { background: var(--accent); border: var(--bd); border-radius: var(--radius); padding: 24px; text-align: center; box-shadow: var(--shadow-sm); }
.stat .num { font-size: 34px; font-weight: 900; color: var(--ink); }
.stat .label { color: #2b2b2b; font-size: 14px; font-weight: 700; margin-top: 4px; }

.list { display: grid; gap: 16px; }
.list .item { display: flex; gap: 16px; align-items: flex-start; background: var(--card); border: var(--bd); border-radius: var(--radius); padding: 18px 20px; box-shadow: var(--shadow-sm); }
.list .badge { flex: 0 0 auto; width: 44px; height: 44px; border: var(--bd); border-radius: 12px; background: var(--accent); color: var(--ink); display: grid; place-items: center; font-weight: 900; }
.list .item h4 { font-size: 17px; font-weight: 800; margin-bottom: 4px; }
.list .item p { color: #444; font-size: 15px; font-weight: 500; }

.team-grid { display: grid; gap: 22px; grid-template-columns: repeat(auto-fit, minmax(210px,1fr)); }
.member { background: var(--card); border: var(--bd); border-radius: var(--radius); padding: 24px; text-align: center; box-shadow: var(--shadow-sm); }
.member:hover { transform: translate(-3px,-3px); box-shadow: var(--shadow); }
.member .avatar { width: 70px; height: 70px; margin: 0 auto 14px; border: var(--bd); border-radius: 50%; background: var(--accent); display: grid; place-items: center; color: var(--ink); font-size: 26px; font-weight: 900; }
.member h4 { font-size: 17px; font-weight: 800; }
.member .role { color: var(--ink); font-weight: 800; font-size: 14px; margin-bottom: 8px; }
.member p { color: #444; font-size: 14px; font-weight: 500; }

.contact-grid { display: grid; grid-template-columns: 1.3fr 1fr; gap: 26px; }
.contact-info li { list-style: none; padding: 13px 0; border-bottom: 2px solid var(--ink); display: flex; gap: 12px; font-weight: 600; }
.contact-info li b { color: var(--ink); width: 84px; flex: 0 0 auto; }
.contact-info li span { color: #444; }
.map-box { background: var(--ink); border: var(--bd); border-radius: var(--radius); min-height: 220px; display: grid; place-items: center; color: #fff; }

.footer { background: var(--ink); color: #fff; padding: 36px 0; border-top: var(--bd); }
.footer .container { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 16px; }
.footer a { color: var(--accent); text-decoration: underline; text-underline-offset: 3px; font-weight: 700; }
.footer .copy { font-size: 13px; color: #cfcfcf; }

@media (max-width: 900px) {
  .nav-links { display: none; position: absolute; top: 78px; left: 0; right: 0; flex-direction: column; background: var(--bg); padding: 12px 24px; border-bottom: var(--bd); }
  .nav-links.open { display: flex; }
  .nav-toggle { display: block; }
  .hero-box { grid-template-columns: 1fr; padding: 30px; }
  .hero h1 { font-size: 34px; }
  .contact-grid { grid-template-columns: 1fr; }
}