/* ============================================================
   数智向善 UOAIS — 全站共享设计系统
   v2026.07 · 最后更新：2026-07-18
   蓝白主色（科技蓝 + 活力橙），岁月潮伴页面另有暖色覆盖变量
   ============================================================ */
:root{
  --blue:#2563EB;
  --blue-dark:#1E3A8A;
  --blue-soft:#EFF4FF;
  --orange:#FF6B35;
  --orange-soft:#FFF1E8;
  --navy:#0B1B3F;
  --navy-2:#24335E;
  --ink:#0B1B3F;
  --text:#5A6478;
  --muted:#64748B;
  --bg-soft:#F4F6FB;
  --border:#E7E7EA;
  --border-soft:#D8DEEA;
  --cjk:"Sarasa Gothic SC","Noto Sans SC","PingFang SC","Microsoft YaHei",sans-serif;
  --display:"Archivo Black","Archivo","Sarasa Gothic SC",sans-serif;
  --shadow:0 4px 12px rgba(11,27,63,.06);
  --shadow-lg:0 6px 16px rgba(11,27,63,.06);
}
*{box-sizing:border-box;margin:0;padding:0;}
html{scroll-behavior:smooth;}
body{
  font-family:var(--cjk);
  color:var(--text);
  background:#fff;
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
}
a{text-decoration:none;color:inherit;}
img{max-width:100%;}
.container{max-width:1440px;margin:0 auto;padding:0 64px;}
.sec{padding:96px 0;}
.sec--soft{background:var(--bg-soft);}
.sec--navy{background:var(--navy);color:#C7D2E8;}

.tag{
  display:inline-block;font-size:13px;font-weight:700;letter-spacing:1px;
  color:var(--blue);background:var(--blue-soft);padding:7px 16px;border-radius:100px;
}
.tag--orange{color:var(--orange);background:var(--orange-soft);}
.sec-head{text-align:center;max-width:800px;margin:0 auto 52px;display:flex;flex-direction:column;gap:12px;align-items:center;}
.sec-title{font-size:36px;font-weight:700;color:var(--ink);line-height:1.3;}
.sec-desc{font-size:16px;color:var(--text);}
.sec--navy .sec-title{color:#fff;}

/* ===== Buttons ===== */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  font-family:var(--cjk);font-weight:700;cursor:pointer;border:none;
  transition:transform .15s, box-shadow .2s, background .2s;
}
.btn--primary{background:var(--blue);color:#fff;padding:10px 22px;border-radius:8px;font-size:14px;}
.btn--primary:hover{background:#1d4fd8;box-shadow:0 6px 16px rgba(37,99,235,.3);}
.btn--cta{background:var(--orange);color:#fff;padding:10px 22px;border-radius:8px;font-size:14px;}
.btn--cta:hover{background:#f05a24;box-shadow:0 6px 16px rgba(255,107,53,.35);}
.btn--lg{padding:16px 34px;font-size:16px;border-radius:8px;}
.btn--ghost{background:#fff;color:var(--blue);border:1px solid var(--border-soft);}
.btn--ghost:hover{border-color:var(--blue);}
.btn--ghost-dark{background:transparent;color:#fff;border:1px solid rgba(255,255,255,.4);}
.btn--ghost-dark:hover{border-color:#fff;}

/* ===== Header + 下拉导航 ===== */
.header{
  position:sticky;top:0;z-index:50;background:#fff;
  border-bottom:1px solid var(--border-soft);
}
.header__inner{display:flex;align-items:center;justify-content:space-between;height:72px;gap:24px;}
.logo{display:flex;align-items:center;gap:8px;font-weight:700;flex-shrink:0;}
.logo__cn{font-size:22px;color:var(--navy);}
.logo__en{font-size:20px;color:var(--blue);font-family:var(--display);letter-spacing:2px;}
.nav{display:flex;align-items:center;gap:6px;}
.nav__item{position:relative;}
.nav__link{
  display:inline-flex;align-items:center;gap:5px;
  font-size:15px;color:var(--text);padding:10px 13px;border-radius:8px;
  transition:color .2s, background .2s;cursor:pointer;background:none;border:none;font-family:var(--cjk);
}
.nav__link:hover{color:var(--blue);background:var(--blue-soft);}
.nav__caret{width:10px;height:10px;transition:transform .2s;}
.nav__item:hover .nav__caret{transform:rotate(180deg);}
.nav__drop{
  position:absolute;top:calc(100% + 6px);left:0;min-width:250px;
  background:#fff;border:1px solid var(--border-soft);border-radius:12px;
  box-shadow:0 12px 32px rgba(11,27,63,.12);padding:8px;
  opacity:0;visibility:hidden;transform:translateY(6px);
  transition:opacity .18s, transform .18s, visibility .18s;
}
.nav__item:hover .nav__drop,
.nav__item:focus-within .nav__drop{opacity:1;visibility:visible;transform:translateY(0);}
.drop__link{display:block;padding:10px 14px;border-radius:8px;transition:background .15s;}
.drop__link:hover{background:var(--blue-soft);}
.drop__title{font-size:14px;font-weight:700;color:var(--ink);}
.drop__link:hover .drop__title{color:var(--blue);}
.drop__sub{font-size:12px;color:var(--muted);margin-top:1px;}
.header__actions{display:flex;align-items:center;gap:14px;flex-shrink:0;}
.login-link{font-size:14px;color:var(--muted);transition:color .2s;}
.login-link:hover{color:var(--blue);}

/* 移动端汉堡 */
.hamburger{display:none;background:none;border:none;cursor:pointer;padding:8px;}
.hamburger span{display:block;width:22px;height:2px;background:var(--ink);margin:5px 0;border-radius:2px;transition:transform .2s, opacity .2s;}
.mnav{display:none;}
body.mnav-open .mnav{
  display:block;position:fixed;inset:72px 0 0 0;z-index:49;background:#fff;
  overflow-y:auto;padding:16px 20px 40px;
}
body.mnav-open{overflow:hidden;}
body.mnav-open .hamburger span:nth-child(1){transform:translateY(7px) rotate(45deg);}
body.mnav-open .hamburger span:nth-child(2){opacity:0;}
body.mnav-open .hamburger span:nth-child(3){transform:translateY(-7px) rotate(-45deg);}
.mnav__group{border-bottom:1px solid var(--border);}
.mnav__label{display:block;font-size:16px;font-weight:700;color:var(--ink);padding:16px 4px;}
.mnav__sub{padding:0 4px 12px;}
.mnav__sub a{display:block;font-size:15px;color:var(--text);padding:9px 12px;border-radius:8px;}
.mnav__sub a:hover{background:var(--blue-soft);color:var(--blue);}
.mnav__cta{margin-top:20px;display:flex;flex-direction:column;gap:12px;}

/* ===== 面包屑 ===== */
.breadcrumbs{padding:18px 0 0;font-size:13px;color:var(--muted);}
.breadcrumbs a{color:var(--muted);transition:color .2s;}
.breadcrumbs a:hover{color:var(--blue);}
.breadcrumbs span{margin:0 6px;color:var(--border-soft);}
.breadcrumbs em{font-style:normal;color:var(--ink);}

/* ===== Hero（子页面通用）===== */
.page-hero{padding:72px 0 80px;text-align:center;}
.page-hero__inner{display:flex;flex-direction:column;align-items:center;gap:24px;}
.page-hero h1{font-size:48px;font-weight:700;color:var(--ink);line-height:1.25;max-width:1000px;letter-spacing:-.5px;}
.page-hero .lead{font-size:18px;color:var(--text);max-width:820px;}
.page-hero__cta{display:flex;gap:16px;flex-wrap:wrap;justify-content:center;}
.hero-trust{font-size:13px;color:var(--muted);}

/* ===== 卡片与网格 ===== */
.grid-2{display:grid;grid-template-columns:repeat(2,1fr);gap:24px;}
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:24px;}
.grid-4{display:grid;grid-template-columns:repeat(4,1fr);gap:20px;}
.card{
  background:#fff;border:1px solid var(--border);border-radius:12px;
  padding:28px;box-shadow:var(--shadow);
}
.card--hover{transition:transform .2s, box-shadow .2s;}
.card--hover:hover{transform:translateY(-4px);box-shadow:0 12px 32px rgba(11,27,63,.1);}
.card__icon{width:40px;height:40px;margin-bottom:14px;color:var(--blue);}
.card__title{font-size:20px;font-weight:700;color:var(--ink);margin-bottom:8px;}
.card__desc{font-size:15px;color:var(--text);line-height:1.65;}
.card__more{display:inline-block;margin-top:14px;font-size:14px;font-weight:700;color:var(--blue);}
.card__more:hover{text-decoration:underline;}

/* ===== 数据统计条 ===== */
.stat-strip{display:flex;justify-content:center;gap:0;flex-wrap:wrap;}
.stat-strip__item{
  flex:1;min-width:170px;text-align:center;padding:18px 12px;
  border-right:1px solid var(--border-soft);
}
.stat-strip__item:last-child{border-right:none;}
.stat-strip__num{font-family:var(--display);font-size:34px;color:var(--blue);line-height:1.2;}
.stat-strip__num em{font-style:normal;}
.stat-strip__label{font-size:14px;color:var(--muted);margin-top:4px;}

/* ===== 指标 ===== */
.metric__num{font-family:var(--display);font-size:30px;color:var(--blue);}
.metric__num--orange{color:var(--orange);}
.metric__label{font-size:14px;color:var(--muted);}

/* ===== FAQ ===== */
.faq{max-width:820px;margin:0 auto;display:flex;flex-direction:column;gap:12px;}
.faq details{
  background:#fff;border:1px solid var(--border);border-radius:12px;
  padding:0;overflow:hidden;box-shadow:var(--shadow);
}
.faq summary{
  cursor:pointer;list-style:none;display:flex;justify-content:space-between;align-items:center;gap:16px;
  padding:18px 22px;font-size:16px;font-weight:700;color:var(--ink);
}
.faq summary::-webkit-details-marker{display:none;}
.faq summary::after{
  content:"+";font-size:20px;color:var(--blue);font-weight:400;flex-shrink:0;
  transition:transform .2s;
}
.faq details[open] summary::after{transform:rotate(45deg);}
.faq .faq__a{padding:0 22px 18px;font-size:15px;color:var(--text);line-height:1.7;}

/* ===== 终极 CTA 横幅 ===== */
.cta-band{background:var(--navy);padding:88px 0;text-align:center;color:#fff;}
.cta-band__title{font-size:34px;font-weight:700;margin-bottom:12px;}
.cta-band__desc{font-size:16px;color:#C7D2E8;margin-bottom:32px;}
.cta-band__aux{margin-top:18px;font-size:14px;color:#8FA3D0;}
.cta-band__aux a{color:#9DC0FF;text-decoration:underline;}

/* ===== 表单 ===== */
.contact-form{
  background:#fff;border:1px solid var(--border-soft);
  border-radius:12px;padding:32px;box-shadow:var(--shadow);
}
.form-row{margin-bottom:18px;}
.form-row label{display:block;font-size:14px;font-weight:600;color:var(--ink);margin-bottom:6px;}
.form-row input,.form-row textarea,.form-row select{
  width:100%;padding:12px 16px;border-radius:8px;
  border:1px solid var(--border-soft);background:var(--bg-soft);color:var(--ink);
  font-size:14px;font-family:var(--cjk);transition:border-color .2s, box-shadow .2s;
}
.form-row input:focus,.form-row textarea:focus,.form-row select:focus{
  outline:none;border-color:var(--blue);box-shadow:0 0 0 3px rgba(37,99,235,.1);
  background:#fff;
}
.form-row textarea{resize:vertical;min-height:100px;}
.form-row select{appearance:none;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='%2364748B' viewBox='0 0 16 16'%3E%3Cpath d='M8 11L3 6h10z'/%3E%3C/svg%3E");background-repeat:no-repeat;background-position:right 14px center;padding-right:36px;}
.submit-btn{
  width:100%;padding:14px;border-radius:8px;border:none;
  background:var(--blue);color:#fff;font-weight:700;font-size:15px;
  cursor:pointer;font-family:var(--cjk);transition:background .2s, box-shadow .2s;
}
.submit-btn:hover{background:#1d4fd8;box-shadow:0 6px 16px rgba(37,99,235,.3);}

/* ===== 版本 / 更新日期标签 ===== */
.version-tag{
  display:inline-block;font-size:12px;color:var(--muted);
  background:var(--bg-soft);border:1px solid var(--border);
  padding:4px 12px;border-radius:100px;
}

/* ===== Footer ===== */
.footer{background:var(--navy);color:#9FB0E0;padding:64px 0 28px;}
.footer__top{display:flex;justify-content:space-between;gap:48px;flex-wrap:wrap;}
.footer__brand{width:340px;}
.footer__brand .logo__cn{color:#fff;}
.footer__brand .logo__en{color:#5B8DEF;}
.footer__desc{font-size:14px;color:#9FB0E0;margin-top:14px;line-height:1.7;}
.footer__col h4{color:#fff;font-size:14px;font-weight:700;margin-bottom:12px;}
.footer__col a{display:block;font-size:14px;color:#9FB0E0;margin-bottom:8px;transition:color .2s;}
.footer__col a:hover{color:#fff;}
.footer__col p{font-size:14px;color:#9FB0E0;margin-bottom:8px;}
.footer__divider{height:1px;background:var(--navy-2);margin:36px 0;}
.footer__bottom{display:flex;justify-content:center;text-align:center;align-items:center;flex-wrap:wrap;gap:24px;}
.footer__copy{font-size:13px;color:#7E8FBF;}
.footer__legal{display:flex;gap:20px;align-items:center;}
.footer__legal a,.footer__legal span{font-size:13px;color:#7E8FBF;}

/* ===== 滚动显现动画 ===== */
.reveal{opacity:0;transform:translateY(18px);transition:opacity .5s ease, transform .5s ease;}
.reveal.is-visible{opacity:1;transform:none;}
@media (prefers-reduced-motion: reduce){
  .reveal{opacity:1;transform:none;transition:none;}
  html{scroll-behavior:auto;}
}

/* ===== 响应式 ===== */
@media (max-width:1180px){
  .container{padding:0 32px;}
  .page-hero h1{font-size:40px;}
  .grid-4{grid-template-columns:repeat(2,1fr);}
}
@media (max-width:960px){
  .nav,.header__actions .login-link{display:none;}
  .hamburger{display:block;}
}
@media (max-width:720px){
  .container{padding:0 20px;}
  .sec{padding:64px 0;}
  .page-hero{padding:56px 0 60px;}
  .page-hero h1{font-size:32px;}
  .page-hero .lead{font-size:16px;}
  .sec-title{font-size:28px;}
  .grid-2,.grid-3,.grid-4{grid-template-columns:1fr;}
  .stat-strip__item{min-width:45%;border-right:none;}
  .cta-band__title{font-size:26px;}
  .footer__brand{width:100%;}
  .header__actions .btn{padding:8px 14px;font-size:13px;}
}