/* ==========================================================================
   妥达信息官网 v0.1 —— 纯静态样式表(无外部依赖,国内加载快)
   设计基准:科技蓝 + 青色点缀,移动端优先
   ========================================================================== */

:root{
  --c-primary:      #0B57D0;
  --c-primary-dark: #0842A0;
  --c-accent:       #00867B;
  --c-ink:          #0E1B2E;
  --c-text:         #3B4A63;
  --c-muted:        #6B7A93;
  --c-line:         #E4E9F2;
  --c-bg:           #FFFFFF;
  --c-bg-soft:      #F5F8FD;
  --c-bg-dark:      #0B1F3F;
  --radius:         14px;
  --radius-sm:      8px;
  --shadow:         0 6px 24px rgba(14,27,46,.08);
  --shadow-lg:      0 16px 48px rgba(14,27,46,.14);
  --container:      1160px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
          "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

*{ margin:0; padding:0; box-sizing:border-box; }
html{ scroll-behavior:smooth; -webkit-text-size-adjust:100%; }
body{
  font-family:var(--font);
  color:var(--c-text);
  background:var(--c-bg);
  line-height:1.75;
  font-size:16px;
}
img{ max-width:100%; display:block; }
a{ color:var(--c-primary); text-decoration:none; }
a:hover{ color:var(--c-primary-dark); }

.container{ max-width:var(--container); margin:0 auto; padding:0 22px; }

/* ---------- 顶部导航 ---------- */
.site-header{
  position:sticky; top:0; z-index:100;
  background:rgba(255,255,255,.92);
  backdrop-filter:blur(10px);
  border-bottom:1px solid transparent;
  transition:border-color .2s, box-shadow .2s;
}
.site-header.scrolled{ border-bottom-color:var(--c-line); box-shadow:0 2px 14px rgba(14,27,46,.06); }
.nav-wrap{ display:flex; align-items:center; justify-content:space-between; height:66px; }
.brand{ display:flex; align-items:center; gap:10px; font-weight:700; color:var(--c-ink); font-size:19px; letter-spacing:.5px; }
.brand svg{ flex:none; }
.brand small{ display:block; font-size:11px; font-weight:400; color:var(--c-muted); letter-spacing:2px; line-height:1; }
.nav{ display:flex; align-items:center; gap:4px; }
.nav a{
  color:var(--c-ink); font-size:15px; padding:8px 13px; border-radius:8px;
  transition:background .15s,color .15s;
}
.nav a:hover{ background:var(--c-bg-soft); color:var(--c-primary); }
.nav a.active{ color:var(--c-primary); font-weight:600; }
.nav .btn{ margin-left:10px; }

.nav-toggle{
  display:none; background:none; border:0; cursor:pointer; padding:8px;
}
.nav-toggle span{ display:block; width:22px; height:2px; background:var(--c-ink); margin:5px 0; border-radius:2px; transition:.2s; }

/* ---------- 按钮 ---------- */
.btn{
  display:inline-flex; align-items:center; justify-content:center; gap:8px;
  padding:12px 26px; border-radius:999px; font-size:15px; font-weight:600;
  border:1.5px solid transparent; cursor:pointer; transition:.18s; white-space:nowrap;
}
.btn-primary{ background:var(--c-primary); color:#fff; }
.btn-primary:hover{ background:var(--c-primary-dark); color:#fff; transform:translateY(-1px); box-shadow:0 8px 22px rgba(11,87,208,.28); }
.btn-ghost{ border-color:var(--c-line); color:var(--c-ink); background:#fff; }
.btn-ghost:hover{ border-color:var(--c-primary); color:var(--c-primary); }
.btn-light{ background:#fff; color:var(--c-primary); }
.btn-light:hover{ color:var(--c-primary-dark); transform:translateY(-1px); }
.btn-sm{ padding:8px 18px; font-size:14px; }
.nav .btn-sm{ padding:9px 20px; }

/* ---------- 首屏 ---------- */
.hero{
  position:relative; overflow:hidden;
  background:
    radial-gradient(900px 420px at 85% -10%, rgba(11,87,208,.10), transparent 60%),
    radial-gradient(700px 380px at -10% 110%, rgba(0,134,123,.10), transparent 55%),
    var(--c-bg);
  padding:86px 0 72px;
}
.hero::after{
  content:""; position:absolute; inset:0;
  background-image:linear-gradient(rgba(11,87,208,.045) 1px, transparent 1px),
                   linear-gradient(90deg, rgba(11,87,208,.045) 1px, transparent 1px);
  background-size:44px 44px;
  mask-image:linear-gradient(to bottom, rgba(0,0,0,.5), transparent 78%);
  -webkit-mask-image:linear-gradient(to bottom, rgba(0,0,0,.5), transparent 78%);
  pointer-events:none;
}
.hero .container{ position:relative; z-index:1; }
.hero-eyebrow{
  display:inline-flex; align-items:center; gap:8px;
  font-size:13px; font-weight:600; color:var(--c-primary);
  background:rgba(11,87,208,.08); padding:6px 14px; border-radius:999px; margin-bottom:22px;
}
.hero h1{
  font-size:clamp(30px, 5vw, 50px); line-height:1.25; color:var(--c-ink);
  font-weight:800; letter-spacing:.5px; max-width:820px;
}
.hero h1 em{
  font-style:normal;
  background:linear-gradient(92deg, var(--c-primary), var(--c-accent));
  -webkit-background-clip:text; background-clip:text; color:transparent;
}
.hero p.lead{ font-size:18px; color:var(--c-muted); max-width:640px; margin:20px 0 34px; }
.hero-actions{ display:flex; gap:14px; flex-wrap:wrap; }

/* ---------- 通用区块 ---------- */
section{ padding:76px 0; }
.section-soft{ background:var(--c-bg-soft); }
.section-head{ max-width:720px; margin-bottom:48px; }
.section-head.center{ margin-left:auto; margin-right:auto; text-align:center; }
.eyebrow{ font-size:13px; font-weight:700; letter-spacing:2px; color:var(--c-accent); text-transform:uppercase; }
.section-head h2{ font-size:clamp(24px,3.4vw,34px); color:var(--c-ink); margin:10px 0 14px; font-weight:750; letter-spacing:.3px; }
.section-head p{ color:var(--c-muted); font-size:16.5px; }

/* ---------- 卡片 ---------- */
.grid{ display:grid; gap:26px; }
.grid-2{ grid-template-columns:repeat(2,1fr); }
.grid-3{ grid-template-columns:repeat(3,1fr); }
.card{
  background:#fff; border:1px solid var(--c-line); border-radius:var(--radius);
  padding:30px 28px; transition:.2s; position:relative; display:flex; flex-direction:column;
}
.card:hover{ transform:translateY(-4px); box-shadow:var(--shadow-lg); border-color:rgba(11,87,208,.24); }
.card .ic{
  width:46px; height:46px; border-radius:12px; display:flex; align-items:center; justify-content:center;
  background:rgba(11,87,208,.09); color:var(--c-primary); margin-bottom:18px; flex:none;
}
.card .ic.green{ background:rgba(0,134,123,.10); color:var(--c-accent); }
.card h3{ color:var(--c-ink); font-size:19px; margin-bottom:10px; font-weight:700; }
.card p{ color:var(--c-text); font-size:15px; flex:1; }
.card .more{ margin-top:18px; font-size:14.5px; font-weight:600; }
.card .tagline{ display:inline-block; font-size:12px; font-weight:700; letter-spacing:1px; color:var(--c-accent); background:rgba(0,134,123,.09); padding:4px 10px; border-radius:6px; margin-bottom:14px; }
.card .tagline.blue{ color:var(--c-primary); background:rgba(11,87,208,.08); }

/* ---------- 功能清单 ---------- */
.feature-list{ list-style:none; display:grid; gap:12px; }
.feature-list li{ display:flex; gap:10px; align-items:flex-start; color:var(--c-text); font-size:15.5px; }
.feature-list li::before{
  content:""; flex:none; width:18px; height:18px; margin-top:5px; border-radius:50%;
  background:rgba(0,134,123,.12) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%2300867B' stroke-width='3.4' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M20 6L9 17l-5-5'/%3E%3C/svg%3E") center/11px no-repeat;
}

/* ---------- 步骤 ---------- */
.steps{ counter-reset:step; display:grid; grid-template-columns:repeat(4,1fr); gap:24px; }
.step{ position:relative; padding-top:64px; }
.step::before{
  counter-increment:step; content:"0" counter(step);
  position:absolute; top:0; left:0;
  font-size:36px; font-weight:800; color:rgba(11,87,208,.16); letter-spacing:2px; line-height:1;
}
.step h4{ color:var(--c-ink); font-size:16.5px; margin-bottom:8px; }
.step p{ color:var(--c-muted); font-size:14.5px; }

/* ---------- CTA 条 ---------- */
.cta-band{
  background:linear-gradient(115deg, var(--c-bg-dark), #123B7A 55%, var(--c-primary-dark));
  border-radius:var(--radius); padding:54px 50px; color:#fff;
  display:flex; align-items:center; justify-content:space-between; gap:30px; flex-wrap:wrap;
  position:relative; overflow:hidden;
}
.cta-band::after{
  content:""; position:absolute; right:-70px; top:-70px; width:260px; height:260px; border-radius:50%;
  background:radial-gradient(circle, rgba(0,134,123,.45), transparent 65%);
}
.cta-band h3{ font-size:clamp(20px,3vw,27px); font-weight:750; margin-bottom:8px; }
.cta-band p{ color:rgba(255,255,255,.75); font-size:15.5px; }
.cta-band .btn{ position:relative; z-index:1; }

/* ---------- FAQ ---------- */
.faq{ max-width:820px; margin:0 auto; }
.faq details{
  border:1px solid var(--c-line); border-radius:var(--radius-sm);
  background:#fff; margin-bottom:12px; overflow:hidden;
}
.faq summary{
  cursor:pointer; list-style:none; padding:18px 52px 18px 22px; position:relative;
  font-weight:600; color:var(--c-ink); font-size:16px;
}
.faq summary::-webkit-details-marker{ display:none; }
.faq summary::after{
  content:"+"; position:absolute; right:20px; top:50%; transform:translateY(-50%);
  font-size:22px; color:var(--c-primary); font-weight:400; transition:transform .2s;
}
.faq details[open] summary::after{ transform:translateY(-50%) rotate(45deg); }
.faq .a{ padding:0 22px 20px; color:var(--c-text); font-size:15px; border-top:1px dashed var(--c-line); padding-top:16px; }

/* ---------- 页脚 ---------- */
.site-footer{ background:var(--c-ink); color:rgba(255,255,255,.72); margin-top:80px; padding:56px 0 30px; font-size:14.5px; }
.foot-grid{ display:grid; grid-template-columns:2fr 1fr 1fr 1fr 1.2fr; gap:30px; margin-bottom:40px; }
.site-footer h5{ color:#fff; font-size:15px; margin-bottom:16px; font-weight:700; }
.site-footer a{ color:rgba(255,255,255,.72); display:block; margin-bottom:10px; }
.site-footer a:hover{ color:#fff; }
.site-footer .brand{ color:#fff; }
.site-footer .brand small{ color:rgba(255,255,255,.5); }
.foot-bottom{
  border-top:1px solid rgba(255,255,255,.12); padding-top:22px;
  display:flex; justify-content:space-between; gap:14px; flex-wrap:wrap; font-size:13px; color:rgba(255,255,255,.55);
}
.foot-bottom a{ display:inline; color:rgba(255,255,255,.55); }
.foot-bottom a:hover{ color:#fff; }

/* ---------- 内页头部 ---------- */
.page-hero{ background:var(--c-bg-soft); padding:66px 0 54px; border-bottom:1px solid var(--c-line); }
.page-hero h1{ font-size:clamp(26px,4vw,38px); color:var(--c-ink); font-weight:800; margin-bottom:14px; }
.page-hero p{ color:var(--c-muted); max-width:680px; font-size:17px; }
.crumb{ font-size:13.5px; color:var(--c-muted); margin-bottom:14px; }
.crumb a{ color:var(--c-muted); }
.crumb a:hover{ color:var(--c-primary); }

/* ---------- 内容排版 ---------- */
.prose h2{ color:var(--c-ink); font-size:24px; margin:38px 0 14px; font-weight:750; }
.prose h3{ color:var(--c-ink); font-size:18.5px; margin:28px 0 10px; font-weight:700; }
.prose p{ margin-bottom:14px; }
.two-col{ display:grid; grid-template-columns:1fr 1fr; gap:48px; align-items:center; }

/* ---------- 徽标/标签行 ---------- */
.chips{ display:flex; flex-wrap:wrap; gap:10px; }
.chip{
  font-size:13.5px; font-weight:600; color:var(--c-primary);
  background:rgba(11,87,208,.07); border:1px solid rgba(11,87,208,.16);
  padding:7px 15px; border-radius:999px;
}
.chip.green{ color:var(--c-accent); background:rgba(0,134,123,.07); border-color:rgba(0,134,123,.16); }

/* ---------- 404 ---------- */
.err-wrap{ min-height:52vh; display:flex; flex-direction:column; align-items:center; justify-content:center; text-align:center; padding:80px 20px; }
.err-wrap .code{ font-size:88px; font-weight:800; letter-spacing:4px; background:linear-gradient(92deg,var(--c-primary),var(--c-accent)); -webkit-background-clip:text; background-clip:text; color:transparent; line-height:1; }

/* ---------- 响应式 ---------- */
@media (max-width: 980px){
  .grid-3{ grid-template-columns:repeat(2,1fr); }
  .steps{ grid-template-columns:repeat(2,1fr); }
  .foot-grid{ grid-template-columns:1fr 1fr; }
}
@media (max-width: 760px){
  .nav{
    position:fixed; inset:66px 0 auto 0; background:#fff; flex-direction:column; align-items:stretch;
    padding:14px 22px 22px; border-bottom:1px solid var(--c-line); box-shadow:var(--shadow);
    display:none;
  }
  .nav.open{ display:flex; }
  .nav a{ padding:12px 10px; border-radius:10px; font-size:16px; }
  .nav .btn{ margin:10px 0 0; justify-content:center; }
  .nav-toggle{ display:block; }
  .grid-3, .grid-2, .two-col{ grid-template-columns:1fr; }
  .steps{ grid-template-columns:1fr; }
  .hero{ padding:56px 0 48px; }
  section{ padding:54px 0; }
  .cta-band{ padding:38px 26px; }
  .foot-grid{ grid-template-columns:1fr; gap:26px; }
}