/* ============ 黑龙江大向科技有限公司 官网样式 ============ */
:root{
  --bg:#f6f9ff;
  --bg-soft:#eef4fe;
  --surface:#ffffff;
  --primary:#1f5cff;
  --primary-600:#1547d6;
  --cyan:#16c2ff;
  --teal:#00c2a8;
  --ink:#0d1b33;
  --muted:#5b6b85;
  --line:#e6ecf7;
  --radius:18px;
  --shadow-sm:0 4px 14px rgba(22,69,180,.06);
  --shadow:0 14px 40px rgba(22,69,180,.12);
  --shadow-lg:0 24px 60px rgba(22,69,180,.18);
  --maxw:1180px;
  --font:"PingFang SC","Microsoft YaHei","Hiragino Sans GB",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:var(--font);
  color:var(--ink);
  background:var(--bg);
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
  text-wrap:pretty;
}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 22px}
.eyebrow{display:inline-flex;align-items:center;gap:8px;font-size:13px;font-weight:700;letter-spacing:.12em;color:var(--primary);text-transform:uppercase}
.eyebrow::before{content:"";width:22px;height:2px;background:linear-gradient(90deg,var(--primary),var(--cyan));border-radius:2px}
.section{padding:84px 0}
.section.alt{background:linear-gradient(180deg,var(--bg) 0%,var(--bg-soft) 100%)}
.section-head{text-align:center;max-width:720px;margin:0 auto 50px}
.section-head h2{font-size:clamp(26px,3.4vw,40px);font-weight:800;letter-spacing:-.02em;margin:14px 0 12px;line-height:1.2}
.section-head p{color:var(--muted);font-size:16px}
.grad-text{background:linear-gradient(120deg,var(--primary),var(--cyan));-webkit-background-clip:text;background-clip:text;color:transparent}

/* ---------- 按钮 ---------- */
.btn{display:inline-flex;align-items:center;gap:8px;padding:13px 26px;border-radius:999px;font-weight:600;font-size:15px;cursor:pointer;border:1px solid transparent;transition:.25s;white-space:nowrap}
.btn-primary{background:linear-gradient(120deg,var(--primary),var(--cyan));color:#fff;box-shadow:0 10px 24px rgba(31,92,255,.32)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 16px 34px rgba(31,92,255,.42)}
.btn-ghost{background:rgba(255,255,255,.7);color:var(--primary);border-color:var(--line)}
.btn-ghost:hover{background:#fff;border-color:var(--primary)}
.btn-light{background:#fff;color:var(--primary)}
.btn-light:hover{transform:translateY(-2px);box-shadow:var(--shadow)}

/* ---------- 顶部导航 ---------- */
.site-header{position:sticky;top:0;z-index:50;background:rgba(246,249,255,.82);backdrop-filter:saturate(180%) blur(14px);border-bottom:1px solid rgba(230,236,247,.7)}
.nav{display:flex;align-items:center;justify-content:space-between;height:70px}
.brand{display:flex;align-items:center;gap:11px;font-weight:800;font-size:19px;letter-spacing:-.01em}
.brand .logo{width:38px;height:38px;border-radius:11px;background:linear-gradient(135deg,var(--primary),var(--cyan));display:grid;place-items:center;color:#fff;font-weight:900;box-shadow:0 6px 16px rgba(31,92,255,.35)}
.brand small{display:block;font-size:11px;font-weight:600;color:var(--muted);letter-spacing:.05em}
.nav-links{display:flex;align-items:center;gap:6px}
.nav-links a{padding:9px 15px;border-radius:10px;font-size:15px;font-weight:500;color:var(--muted);transition:.2s}
.nav-links a:hover,.nav-links a.active{color:var(--primary);background:rgba(31,92,255,.07)}
.nav-cta{margin-left:10px}
.menu-toggle{display:none;background:none;border:0;cursor:pointer;color:var(--ink);padding:8px}

/* ---------- Hero ---------- */
.hero{position:relative;overflow:hidden;padding:96px 0 84px;background:
  radial-gradient(1100px 520px at 78% -10%,rgba(22,194,255,.20),transparent 60%),
  radial-gradient(900px 500px at 8% 8%,rgba(31,92,255,.16),transparent 55%),
  linear-gradient(180deg,#fff,#f3f8ff);}
.hero::after{content:"";position:absolute;inset:0;background-image:linear-gradient(rgba(31,92,255,.05) 1px,transparent 1px),linear-gradient(90deg,rgba(31,92,255,.05) 1px,transparent 1px);background-size:46px 46px;mask-image:radial-gradient(900px 500px at 70% 10%,#000,transparent 75%);pointer-events:none}
.hero .wrap{position:relative;z-index:2;display:grid;grid-template-columns:1.15fr .85fr;gap:40px;align-items:center}
.hero h1{font-size:clamp(34px,4.6vw,58px);line-height:1.08;font-weight:850;letter-spacing:-.03em;margin:18px 0 20px}
.hero p.lead{font-size:18px;color:var(--muted);max-width:540px;margin-bottom:30px}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap}
.hero-pills{display:flex;gap:10px;flex-wrap:wrap;margin-top:34px}
.pill{display:inline-flex;align-items:center;gap:7px;background:#fff;border:1px solid var(--line);padding:8px 15px;border-radius:999px;font-size:13px;font-weight:600;color:var(--ink);box-shadow:var(--shadow-sm)}
.pill .dot{width:8px;height:8px;border-radius:50%;background:linear-gradient(120deg,var(--primary),var(--cyan))}
.hero-visual{position:relative;aspect-ratio:1/1;display:grid;place-items:center}
.hero-visual .ring{position:absolute;border-radius:50%;border:1px solid rgba(31,92,255,.18)}
.hero-visual .r1{inset:0;animation:spin 26s linear infinite}
.hero-visual .r2{inset:14%;border-style:dashed;animation:spin 18s linear infinite reverse}
.hero-visual .core{width:54%;height:54%;border-radius:28px;background:linear-gradient(135deg,var(--primary),var(--cyan));box-shadow:0 30px 60px rgba(31,92,255,.35);display:grid;place-items:center;color:#fff;position:relative;z-index:2;animation:float 6s ease-in-out infinite}
.hero-visual .core svg{width:46%;height:46%}
.node{position:absolute;width:13px;height:13px;border-radius:50%;background:#fff;border:3px solid var(--primary);box-shadow:0 0 0 5px rgba(31,92,255,.12)}
.n1{top:8%;left:18%}.n2{top:30%;right:6%}.n3{bottom:14%;left:8%}.n4{bottom:24%;right:20%}
@keyframes spin{to{transform:rotate(360deg)}}
@keyframes float{0%,100%{transform:translateY(0)}50%{transform:translateY(-14px)}}

/* ---------- 数据实力 ---------- */
.stats{display:grid;grid-template-columns:repeat(5,1fr);gap:18px}
.stat{background:rgba(255,255,255,.75);border:1px solid var(--line);border-radius:var(--radius);padding:26px 20px;text-align:center;backdrop-filter:blur(6px);transition:.25s}
.stat:hover{transform:translateY(-4px);box-shadow:var(--shadow)}
.stat .num{font-size:38px;font-weight:850;letter-spacing:-.02em;background:linear-gradient(120deg,var(--primary),var(--cyan));-webkit-background-clip:text;background-clip:text;color:transparent}
.stat .lbl{color:var(--muted);font-size:14px;margin-top:4px}

/* ---------- 卡片网格 ---------- */
.grid{display:grid;gap:24px}
.grid-3{grid-template-columns:repeat(3,1fr)}
.grid-2{grid-template-columns:repeat(2,1fr)}
.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:28px;box-shadow:var(--shadow-sm);transition:.28s;position:relative;overflow:hidden}
.card:hover{transform:translateY(-6px);box-shadow:var(--shadow);border-color:rgba(31,92,255,.3)}
.card .ic{width:54px;height:54px;border-radius:14px;background:linear-gradient(135deg,var(--primary),var(--cyan));display:grid;place-items:center;color:#fff;margin-bottom:16px}
.card .ic svg{width:26px;height:26px}
.card h3{font-size:19px;font-weight:750;margin-bottom:8px}
.card p{color:var(--muted);font-size:14.5px}
.card .more{display:inline-flex;align-items:center;gap:6px;margin-top:14px;color:var(--primary);font-weight:600;font-size:14px}

/* 业务卡片连接线装饰 */
.svc-card .bar{position:absolute;left:0;top:0;height:4px;width:100%;background:linear-gradient(90deg,var(--primary),var(--cyan));transform:scaleX(0);transform-origin:left;transition:.3s}
.svc-card:hover .bar{transform:scaleX(1)}

/* ---------- 产品/案例封面 ---------- */
.cover{height:170px;border-radius:14px;position:relative;overflow:hidden;display:grid;place-items:center;color:#fff}
.cover svg{width:54px;height:54px;opacity:.92}
.cover .cat{position:absolute;top:12px;left:12px;background:rgba(255,255,255,.22);backdrop-filter:blur(4px);padding:4px 12px;border-radius:999px;font-size:12px;font-weight:600}
.cover .yr{position:absolute;bottom:12px;right:12px;font-size:13px;font-weight:700;background:rgba(0,0,0,.18);padding:3px 10px;border-radius:8px}

/* ---------- 新闻列表 ---------- */
.news-item{display:flex;gap:18px;padding:20px;border:1px solid var(--line);border-radius:var(--radius);background:#fff;transition:.25s}
.news-item:hover{box-shadow:var(--shadow);transform:translateY(-3px)}
.news-date{flex:0 0 86px;text-align:center;background:var(--bg-soft);border-radius:14px;padding:12px 6px;color:var(--primary);font-weight:800}
.news-date .d{font-size:26px;line-height:1}.news-date .m{font-size:12px;color:var(--muted)}
.news-item h3{font-size:17px;font-weight:700;margin-bottom:6px}
.news-item p{color:var(--muted);font-size:14px}

/* ---------- 关于/正文 ---------- */
.prose{max-width:840px;margin:0 auto}
.prose p{color:#33425e;font-size:16.5px;white-space:pre-line;margin-bottom:16px}
.timeline{position:relative;margin-top:10px;padding-left:26px}
.timeline::before{content:"";position:absolute;left:7px;top:6px;bottom:6px;width:2px;background:linear-gradient(180deg,var(--primary),var(--cyan))}
.tl-item{position:relative;padding:0 0 22px 18px}
.tl-item::before{content:"";position:absolute;left:-23px;top:5px;width:14px;height:14px;border-radius:50%;background:#fff;border:3px solid var(--primary)}
.tl-item .t{font-weight:700;color:var(--primary)}

/* ---------- 联系 ---------- */
.contact-grid{display:grid;grid-template-columns:1fr 1fr;gap:30px;align-items:start}
.info-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:30px;box-shadow:var(--shadow-sm)}
.info-row{display:flex;gap:14px;padding:16px 0;border-bottom:1px dashed var(--line)}
.info-row:last-child{border-bottom:0}
.info-row .ic{width:42px;height:42px;flex:0 0 42px;border-radius:11px;background:var(--bg-soft);color:var(--primary);display:grid;place-items:center}
.info-row .ic svg{width:20px;height:20px}
.info-row .k{font-size:13px;color:var(--muted)}
.info-row .v{font-weight:600}
.form-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:30px;box-shadow:var(--shadow-sm)}
.field{margin-bottom:16px}
.field label{display:block;font-size:14px;font-weight:600;margin-bottom:7px}
.field input,.field textarea{width:100%;padding:12px 14px;border:1px solid var(--line);border-radius:11px;font-family:inherit;font-size:15px;background:#fbfdff;transition:.2s}
.field input:focus,.field textarea:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 3px rgba(31,92,255,.12)}
.field textarea{resize:vertical;min-height:110px}
.form-note{padding:12px 14px;border-radius:11px;font-size:14px;margin-bottom:14px;display:none}
.form-note.ok{display:block;background:#e8faf3;color:#04895f;border:1px solid #b7ecd6}
.form-note.err{display:block;background:#fdecec;color:#c0392b;border:1px solid #f3c4c4}

/* ---------- 页脚 ---------- */
.site-footer{background:#0c1730;color:#aab8d4;padding:56px 0 26px;margin-top:30px}
.footer-top{display:grid;grid-template-columns:1.5fr 1fr 1fr 1.3fr;gap:30px}
.site-footer h4{color:#fff;font-size:16px;margin-bottom:16px}
.site-footer a{color:#aab8d4;font-size:14px;display:block;padding:5px 0;transition:.2s}
.site-footer a:hover{color:#fff}
.footer-brand p{font-size:14px;line-height:1.8;margin-top:14px;max-width:300px}
.footer-bottom{border-top:1px solid rgba(255,255,255,.08);margin-top:38px;padding-top:20px;font-size:13px;color:#7f8db0;display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px}
.footer-bottom a{display:inline;color:#9fb0d6}

/* ---------- 滚动揭示动画 ---------- */
.reveal{opacity:0;transform:translateY(26px);transition:opacity .7s ease,transform .7s ease}
.reveal.in{opacity:1;transform:none}
@media (prefers-reduced-motion:reduce){.reveal{opacity:1;transform:none}.hero-visual *{animation:none!important}}

/* ---------- 响应式 ---------- */
@media (max-width:980px){
  .hero .wrap{grid-template-columns:1fr}
  .hero-visual{max-width:380px;margin:10px auto 0}
  .stats{grid-template-columns:repeat(2,1fr)}
  .grid-3{grid-template-columns:repeat(2,1fr)}
  .contact-grid{grid-template-columns:1fr}
  .footer-top{grid-template-columns:1fr 1fr}
}
@media (max-width:720px){
  .nav-links{position:fixed;inset:70px 0 auto 0;flex-direction:column;align-items:stretch;background:#fff;padding:14px 18px 22px;gap:4px;box-shadow:var(--shadow);transform:translateY(-130%);transition:.3s;z-index:40}
  .nav-links.open{transform:none}
  .nav-links a{padding:13px 12px}
  .menu-toggle{display:block}
  .nav-cta{display:none}
  .grid-3,.grid-2{grid-template-columns:1fr}
  .section{padding:60px 0}
  .footer-top{grid-template-columns:1fr}
}

/* 图标安全约束：按钮/页脚内的行内图标固定尺寸，防止 SVG 默认巨尺寸 */
.btn svg{width:18px;height:18px;flex:0 0 auto}
.site-footer a svg,.site-footer span svg{width:16px;height:16px;flex:0 0 auto}