/* ============================================================
   syoungtech.com 企业官网样式
   合规要点：页脚底部中央悬挂备案号并链接工信部
   ============================================================ */

:root {
  --brand: #0b5cad;
  --brand-dark: #08437a;
  --brand-light: #e8f1fb;
  --text: #1f2328;
  --text-sub: #5b6472;
  --border: #e3e7ed;
  --bg-soft: #f6f8fa;
  --white: #ffffff;
  --maxw: 1080px;
}

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

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Source Han Sans SC", sans-serif;
  color: var(--text);
  background: var(--white);
  line-height: 1.75;
  font-size: 15px;
}

a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ---------- 顶部导航 ---------- */
.site-header {
  background: var(--white);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}
.site-header .inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 66px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 19px;
  font-weight: 700;
  color: var(--text);
}
.brand:hover { text-decoration: none; }
.brand .logo {
  width: 34px; height: 34px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--brand), #1a7fd4);
  color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 16px; font-weight: 700;
}
.nav { display: flex; gap: 30px; }
.nav a { color: var(--text-sub); font-size: 15px; }
.nav a:hover, .nav a.active { color: var(--brand); text-decoration: none; font-weight: 600; }

/* ---------- 通用区块 ---------- */
.section { padding: 68px 0; }
.section.alt { background: var(--bg-soft); }
.section-title { text-align: center; margin-bottom: 44px; }
.section-title h2 { font-size: 28px; letter-spacing: .5px; margin-bottom: 10px; }
.section-title p { color: var(--text-sub); font-size: 15px; }
.section-title .bar {
  width: 44px; height: 3px; background: var(--brand);
  margin: 0 auto 16px; border-radius: 2px;
}

.grid { display: grid; gap: 24px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* ---------- 首页 Hero ---------- */
.hero {
  background: linear-gradient(135deg, var(--brand-dark) 0%, var(--brand) 55%, #1a7fd4 100%);
  color: #fff;
  padding: 96px 0 104px;
}
.hero h1 { font-size: 38px; line-height: 1.35; margin-bottom: 20px; font-weight: 700; }
.hero p { font-size: 17px; opacity: .92; max-width: 720px; }
.hero .btn {
  display: inline-block;
  margin-top: 30px;
  padding: 12px 30px;
  background: #fff;
  color: var(--brand);
  border-radius: 6px;
  font-weight: 600;
}
.hero .btn:hover { text-decoration: none; background: #eef5fd; }

/* ---------- 卡片 ---------- */
.card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 28px 24px;
  transition: box-shadow .2s, transform .2s;
}
.card:hover { box-shadow: 0 8px 24px rgba(11, 92, 173, .1); transform: translateY(-2px); }
.card h3 { font-size: 17px; margin-bottom: 10px; color: var(--text); }
.card p { color: var(--text-sub); font-size: 14px; }
.card .ico {
  width: 42px; height: 42px; border-radius: 9px;
  background: var(--brand-light); color: var(--brand);
  display: flex; align-items: center; justify-content: center;
  font-size: 20px; margin-bottom: 14px;
}

/* ---------- 数据条 ---------- */
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; text-align: center; }
.stat .num { font-size: 32px; font-weight: 700; color: var(--brand); }
.stat .label { color: var(--text-sub); font-size: 14px; margin-top: 4px; }

/* ---------- 内页 ---------- */
.page-head {
  background: var(--brand-light);
  padding: 52px 0;
  border-bottom: 1px solid var(--border);
}
.page-head h1 { font-size: 30px; margin-bottom: 8px; }
.page-head .crumb { color: var(--text-sub); font-size: 14px; }

.prose h2 { font-size: 22px; margin: 34px 0 14px; padding-left: 12px; border-left: 4px solid var(--brand); }
.prose p { color: var(--text-sub); margin-bottom: 14px; }
.prose ul { color: var(--text-sub); margin: 0 0 16px 22px; }
.prose li { margin-bottom: 8px; }

.info-list { border: 1px solid var(--border); border-radius: 10px; overflow: hidden; background: #fff; }
.info-list div {
  display: flex; border-bottom: 1px solid var(--border);
}
.info-list div:last-child { border-bottom: none; }
.info-list dt {
  width: 130px; flex: none; padding: 14px 18px;
  background: var(--bg-soft); color: var(--text-sub); font-size: 14px;
}
.info-list dd { padding: 14px 18px; flex: 1; }

/* ---------- 系统入口 ---------- */
.sys-entry {
  border: 1px dashed var(--brand);
  background: var(--brand-light);
  border-radius: 10px;
  padding: 26px 28px;
}
.sys-entry h3 { margin-bottom: 8px; font-size: 18px; }
.sys-entry p { color: var(--text-sub); font-size: 14px; margin-bottom: 14px; }

/* ============================================================
   合规关键项：页脚 —— 备案号必须位于页面底部中央，并链接工信部
   样式中已固定 text-align:center，请勿修改为 left
   ============================================================ */
.site-footer {
  background: #2f3742;
  color: #a9b4c2;
  padding: 26px 0;
  text-align: center;          /* ← 底部居中 */
  font-size: 13px;
}
.site-footer .links { margin-bottom: 10px; }
.site-footer .links a { color: #cfd8e3; margin: 0 12px; }
.site-footer .icp a {
  color: #cfd8e3;
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 255, 255, .35);
}
.site-footer .icp a:hover { color: #fff; border-bottom-color: #fff; }
.site-footer .copyright { margin-top: 8px; font-size: 12px; color: #7d8794; }

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  .grid-3, .grid-4, .grid-2 { grid-template-columns: 1fr 1fr; }
  .stats { grid-template-columns: 1fr 1fr; }
  .nav { gap: 16px; font-size: 14px; }
  .hero h1 { font-size: 27px; }
}
@media (max-width: 600px) {
  .grid-3, .grid-4, .grid-2 { grid-template-columns: 1fr; }
  .section { padding: 44px 0; }
  .nav a.hide-sm { display: none; }
}