/* ============================================================
   山衡工控 · 首页视觉稿 v1
   深色硬核 + 工程黄
   ============================================================ */

:root{
  --bg:#0d1014;
  --bg-2:#12171d;
  --bg-3:#171d24;
  --card:#181f27;
  --line:#27313c;
  --text:#e9edf2;
  --text-2:#9aa6b3;
  --text-3:#6b7682;
  --yellow:#ffb400;
  --yellow-2:#ffc93d;
  --yellow-dim:rgba(255,180,0,.12);
  --radius:10px;
  --shadow:0 18px 50px rgba(0,0,0,.45);
  --w:1200px;
  --nav-h:72px;
}

*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:var(--nav-h)}
body{
  font-family:"PingFang SC","Microsoft YaHei","Hiragino Sans GB",system-ui,-apple-system,sans-serif;
  background:var(--bg);color:var(--text);line-height:1.7;
  -webkit-font-smoothing:antialiased;overflow-x:hidden;
}
img{display:block;max-width:100%}
a{color:inherit;text-decoration:none}
ul,ol{list-style:none}
button{font-family:inherit;cursor:pointer;border:none;background:none;color:inherit}
input,select,textarea{font-family:inherit}

.container{width:100%;max-width:var(--w);margin:0 auto;padding:0 24px}
.narrow{max-width:860px}
.hide-m{display:inline}

/* ---------- 按钮 ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  height:50px;padding:0 30px;border-radius:6px;font-size:16px;font-weight:600;
  letter-spacing:1px;transition:.25s;white-space:nowrap;
}
.btn-primary{background:var(--yellow);color:#1a1400}
.btn-primary:hover{background:var(--yellow-2);transform:translateY(-2px);box-shadow:0 10px 26px rgba(255,180,0,.28)}
.btn-ghost{border:1px solid rgba(255,255,255,.35);color:#fff;background:rgba(255,255,255,.06);backdrop-filter:blur(4px)}
.btn-ghost:hover{border-color:var(--yellow);color:var(--yellow)}
.btn-lg{height:56px;font-size:17px;padding:0 46px}

/* ---------- 电话小图标 ---------- */
.ico-phone{
  width:18px;height:18px;flex:none;
  background:url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='%23ffb400'%3E%3Cpath d='M6.6 10.8c1.4 2.8 3.8 5.1 6.6 6.6l2.2-2.2c.3-.3.7-.4 1-.2 1.1.4 2.3.6 3.6.6.6 0 1 .4 1 1V20c0 .6-.4 1-1 1C10.6 21 3 13.4 3 4c0-.6.4-1 1-1h3.5c.6 0 1 .4 1 1 0 1.2.2 2.4.6 3.6.1.4 0 .8-.3 1l-2.2 2.2z'/%3E%3C/svg%3E") center/contain no-repeat;
}
.ico-wechat{
  width:20px;height:20px;background:url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='%23fff'%3E%3Cpath d='M9 4C4.9 4 1.6 6.8 1.6 10.2c0 2 1.1 3.7 2.9 4.8l-.7 2.2 2.6-1.3c.8.2 1.7.4 2.6.4h.8a5.3 5.3 0 0 1-.2-1.5c0-3.2 3.1-5.8 6.9-5.8h.6C16.4 5.9 13 4 9 4zM6.5 8.8a.9.9 0 1 1 0-1.8.9.9 0 0 1 0 1.8zm5 0a.9.9 0 1 1 0-1.8.9.9 0 0 1 0 1.8zM16.5 10c-3.3 0-6 2.3-6 5.1 0 2.8 2.7 5.1 6 5.1.7 0 1.4-.1 2.1-.3l2.1 1.1-.6-1.7c1.5-.9 2.4-2.4 2.4-4.2 0-2.8-2.7-5.1-6-5.1zm-2 4.3a.8.8 0 1 1 0-1.6.8.8 0 0 1 0 1.6zm4 0a.8.8 0 1 1 0-1.6.8.8 0 0 1 0 1.6z'/%3E%3C/svg%3E") center/contain no-repeat;
}

/* ---------- 导航 ---------- */
.nav{position:fixed;top:0;left:0;right:0;z-index:100;height:var(--nav-h);transition:.3s}
.nav.scrolled{background:rgba(13,16,20,.92);backdrop-filter:blur(12px);border-bottom:1px solid var(--line)}
.nav-inner{display:flex;align-items:center;height:var(--nav-h);gap:36px}
.brand{display:flex;align-items:center;gap:12px;flex:none}
.brand-mark{
  width:42px;height:42px;border-radius:6px;object-fit:contain;flex:none;
}
.brand-txt strong{display:block;font-size:19px;letter-spacing:2px;line-height:1.2}
.brand-txt em{display:block;font-style:normal;font-size:9px;letter-spacing:2px;color:var(--text-3)}
.menu{display:flex;gap:6px;margin-left:auto}
.menu a{padding:8px 14px;font-size:15px;color:var(--text-2);border-radius:4px;transition:.2s;position:relative}
.menu a:hover,.menu a.active{color:#fff}
.menu a:not(.menu-cta):hover::after{content:"";position:absolute;left:14px;right:14px;bottom:2px;height:2px;background:var(--yellow)}
.menu-cta{background:var(--yellow-dim);color:var(--yellow)!important;border:1px solid rgba(255,180,0,.4)}
.menu-cta:hover{background:var(--yellow)!important;color:#151000!important}
.nav-tel{display:flex;align-items:center;gap:9px;flex:none;padding-left:20px;border-left:1px solid var(--line)}
.nav-tel em{display:block;font-style:normal;font-size:10px;color:var(--text-3);line-height:1.2}
.nav-tel strong{display:block;font-size:17px;color:var(--yellow);letter-spacing:.5px;line-height:1.3}
.nav-burger{display:none;flex-direction:column;gap:5px;margin-left:auto;padding:8px}
.nav-burger span{width:24px;height:2px;background:#fff;transition:.3s}

/* ---------- 首屏 ---------- */
.hero{position:relative;min-height:100vh;display:flex;align-items:center;padding:120px 0 90px;overflow:hidden}
.hero-bg{position:absolute;inset:0;background-size:cover;background-position:center;transform:scale(1.05);animation:heroZoom 18s ease-in-out infinite alternate}
@keyframes heroZoom{to{transform:scale(1.12)}}
.hero-mask{position:absolute;inset:0;background:
  linear-gradient(90deg,rgba(10,12,15,.95) 0%,rgba(10,12,15,.78) 42%,rgba(10,12,15,.35) 100%),
  linear-gradient(0deg,rgba(13,16,20,.95) 0%,rgba(13,16,20,.25) 45%,rgba(13,16,20,.3) 100%)}
.hero-inner{position:relative;z-index:2}
.hero-tag{
  display:inline-block;padding:7px 16px;border:1px solid rgba(255,180,0,.45);border-radius:30px;
  color:var(--yellow);font-size:13px;letter-spacing:2px;margin-bottom:26px;background:rgba(255,180,0,.07)
}
.hero-title{font-size:56px;font-weight:900;line-height:1.22;letter-spacing:2px}
.hero-title span{color:var(--yellow);position:relative}
.hero-sub{margin:24px 0 40px;color:#cdd5de;font-size:17px;line-height:2}
.hero-btns{display:flex;gap:18px;flex-wrap:wrap}
.hero-trust{display:flex;gap:32px;margin-top:54px;flex-wrap:wrap}
.hero-trust span{display:flex;align-items:center;gap:9px;color:var(--text-2);font-size:14px}
.hero-trust i{width:6px;height:6px;background:var(--yellow);border-radius:50%;box-shadow:0 0 0 4px rgba(255,180,0,.15)}
.hero-scroll{position:absolute;left:50%;bottom:26px;transform:translateX(-50%);z-index:2;width:24px;height:40px;border:2px solid rgba(255,255,255,.35);border-radius:14px;display:block}
.hero-scroll span{position:absolute;left:50%;top:8px;width:4px;height:8px;margin-left:-2px;background:var(--yellow);border-radius:2px;animation:scrollDot 1.6s infinite}
@keyframes scrollDot{0%{opacity:0;transform:translateY(0)}30%{opacity:1}100%{opacity:0;transform:translateY(14px)}}

/* ---------- 通用区块 ---------- */
.section{padding:96px 0}
.section-dark{background:var(--bg-2);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.sec-head{text-align:center;max-width:680px;margin:0 auto 56px}
.sec-head em{display:block;font-style:normal;color:var(--yellow);font-size:13px;letter-spacing:5px;font-weight:600;margin-bottom:12px}
.sec-head h2{font-size:36px;font-weight:800;letter-spacing:2px}
.sec-head p{color:var(--text-2);margin-top:14px;font-size:15px}
.sec-head-row{display:flex;align-items:flex-end;justify-content:space-between;text-align:left;max-width:none}
.sec-head-row>div{max-width:680px}
.link-more{color:var(--yellow);font-size:15px;white-space:nowrap;flex:none}
.link-more:hover{color:var(--yellow-2)}
.kicker{display:block;font-style:normal;color:var(--yellow);font-size:13px;letter-spacing:4px;font-weight:600;margin-bottom:14px}

/* ---------- 业务卡片 ---------- */
.biz-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:26px}
.biz-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;transition:.3s;display:block}
.biz-card:hover{transform:translateY(-8px);border-color:rgba(255,180,0,.5);box-shadow:var(--shadow)}
.biz-img{aspect-ratio:4/3;overflow:hidden;background:var(--bg-3)}
.biz-img img{width:100%;height:100%;object-fit:cover;transition:.6s;filter:saturate(.85)}
.biz-card:hover .biz-img img{transform:scale(1.08);filter:saturate(1.1)}
.biz-body{padding:26px 24px 30px}
.biz-body h3{font-size:21px;margin-bottom:12px;letter-spacing:1px}
.biz-body h3::before{content:"";display:inline-block;width:4px;height:18px;background:var(--yellow);margin-right:10px;vertical-align:-2px}
.biz-body p{color:var(--text-2);font-size:14px;min-height:96px}
.biz-more{display:inline-block;margin-top:16px;color:var(--yellow);font-size:14px;font-weight:600}

/* ---------- 案例 ---------- */
.case-grid{display:grid;grid-template-columns:1.25fr 1fr;grid-template-rows:1fr 1fr;gap:22px;min-height:560px}
.case-card{position:relative;border-radius:var(--radius);overflow:hidden;display:block;background:var(--bg-3)}
.case-card img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;transition:.6s}
.case-card:hover img{transform:scale(1.07)}
.case-mask{position:absolute;inset:0;background:linear-gradient(0deg,rgba(8,10,13,.95) 0%,rgba(8,10,13,.35) 45%,rgba(8,10,13,.05) 75%)}
.case-info{position:absolute;left:0;right:0;bottom:0;padding:26px 28px}
.case-cat{display:inline-block;padding:4px 12px;background:var(--yellow);color:#1a1400;font-size:12px;font-weight:700;border-radius:3px;margin-bottom:12px}
.case-info h3{font-size:19px;line-height:1.5;margin-bottom:8px}
.case-lg h3{font-size:23px}
.case-info p{color:var(--text-2);font-size:14px;max-height:0;overflow:hidden;opacity:0;transition:.4s}
.case-card:hover .case-info p{max-height:80px;opacity:1;margin-top:4px}

/* ---------- 优势 + 数据 ---------- */
.adv-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:22px}
.adv-item{padding:34px 24px;border:1px solid var(--line);border-radius:var(--radius);background:var(--card);text-align:center;transition:.3s}
.adv-item:hover{border-color:rgba(255,180,0,.45);transform:translateY(-6px)}
.adv-ico{display:block;width:54px;height:54px;margin:0 auto 18px;border-radius:12px;background:var(--yellow-dim);position:relative}
.adv-ico::after{content:"";position:absolute;inset:0;background-position:center;background-repeat:no-repeat;background-size:28px}
.ico-survey::after{background-image:url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='%23ffb400'%3E%3Cpath d='M12 2C8.1 2 5 5.1 5 9c0 5.2 7 13 7 13s7-7.8 7-13c0-3.9-3.1-7-7-7zm0 9.5A2.5 2.5 0 1 1 12 6.5a2.5 2.5 0 0 1 0 5z'/%3E%3C/svg%3E")}
.ico-on-site::after{background-image:url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='%23ffb400'%3E%3Cpath d='M12 2l-9 5v3h18V7l-9-5zM4 12v6H2v2h20v-2h-2v-6h-2v6h-4v-6h-2v6H8v-6H4z'/%3E%3C/svg%3E")}
.ico-case::after{background-image:url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='%23ffb400'%3E%3Cpath d='M20 6h-4l-2-2H10L8 6H4a2 2 0 0 0-2 2v10a2 2 0 0 0 2 2h16a2 2 0 0 0 2-2V8a2 2 0 0 0-2-2zm-8 11a4 4 0 1 1 0-8 4 4 0 0 1 0 8z'/%3E%3C/svg%3E")}
.ico-warranty::after{background-image:url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='%23ffb400'%3E%3Cpath d='M12 1L3 5v6c0 5.6 3.8 10.7 9 12 5.2-1.3 9-6.4 9-12V5l-9-4zm-1.2 14.4L7 11.6l1.4-1.4 2.4 2.4 5-5L17.2 9l-6.4 6.4z'/%3E%3C/svg%3E")}
.adv-item h3{font-size:19px;margin-bottom:10px}
.adv-item p{color:var(--text-2);font-size:14px}
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:22px;margin-top:26px;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden}
.stat{padding:38px 20px;text-align:center;background:var(--card)}
.stat+.stat{border-left:1px solid var(--line)}
.stat strong{display:block;font-size:44px;font-weight:900;color:var(--yellow);line-height:1.1}
.stat-unit{font-size:16px;font-weight:600;margin-left:2px}
.stat span:not(.stat-unit){font-size:14px;color:var(--text-2)}

/* ---------- 时间轴 ---------- */
.timeline{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.timeline li{position:relative;background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:28px 26px;transition:.3s}
.timeline li:hover{border-color:rgba(255,180,0,.4);transform:translateY(-4px)}
.tl-step{font-size:40px;font-weight:900;color:transparent;-webkit-text-stroke:1.5px rgba(255,180,0,.55);line-height:1;margin-bottom:14px}
.tl-body h3{font-size:19px;margin-bottom:8px}
.tl-body p{color:var(--text-2);font-size:14px}
.tl-pay{position:absolute;top:24px;right:22px;padding:4px 12px;background:var(--yellow);color:#1a1400;font-size:12px;font-weight:700;border-radius:3px}
.process-note{text-align:center;color:var(--text-3);font-size:13px;margin-top:34px}

/* ---------- 关于 ---------- */
.about-grid{display:grid;grid-template-columns:1fr 1.05fr;gap:60px;align-items:center}
.about-img{border-radius:var(--radius);overflow:hidden;border:1px solid var(--line);box-shadow:var(--shadow)}
.about-img img{width:100%;aspect-ratio:4/3.4;object-fit:cover}
.about-txt h2{font-size:34px;line-height:1.35;margin-bottom:22px}
.about-txt>p{color:var(--text-2);font-size:15px;margin-bottom:26px}
.about-list{margin-bottom:34px}
.about-list li{position:relative;padding-left:28px;margin-bottom:13px;color:#cdd5de;font-size:15px}
.about-list li::before{content:"";position:absolute;left:0;top:9px;width:14px;height:8px;border-left:2.5px solid var(--yellow);border-bottom:2.5px solid var(--yellow);transform:rotate(-45deg)}

/* ---------- FAQ ---------- */
.faq-item{border:1px solid var(--line);border-radius:8px;margin-bottom:14px;background:var(--card);overflow:hidden}
.faq-q{width:100%;display:flex;align-items:center;justify-content:space-between;gap:16px;padding:22px 26px;text-align:left;font-size:16px;font-weight:600}
.faq-q:hover{color:var(--yellow)}
.faq-ico{position:relative;width:16px;height:16px;flex:none}
.faq-ico::before,.faq-ico::after{content:"";position:absolute;background:var(--yellow);transition:.3s}
.faq-ico::before{left:0;right:0;top:7px;height:2px}
.faq-ico::after{top:0;bottom:0;left:7px;width:2px}
.faq-item.open .faq-ico::after{transform:rotate(90deg);opacity:0}
.faq-a{max-height:0;overflow:hidden;transition:max-height .35s ease}
.faq-a p{padding:0 26px 24px;color:var(--text-2);font-size:14.5px}

/* ---------- 底部 CTA / 表单 ---------- */
.cta{padding:100px 0;background:
  radial-gradient(900px 380px at 50% -10%,rgba(255,180,0,.14),transparent 70%),var(--bg-2);
  border-top:1px solid var(--line)}
.cta-inner{text-align:center;max-width:860px}
.cta-inner h2{font-size:36px;font-weight:800;letter-spacing:2px}
.cta-inner>p{color:var(--text-2);margin:14px 0 40px}
.cta-form{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:30px;text-align:left}
.form-row{display:grid;grid-template-columns:1fr 1fr 1fr;gap:16px;margin-bottom:16px}
.cta-form input,.cta-form select,.cta-form textarea{
  width:100%;background:var(--bg-2);border:1px solid var(--line);border-radius:6px;
  padding:14px 16px;color:var(--text);font-size:15px;outline:none;transition:.2s;
}
.cta-form textarea{resize:vertical;margin-bottom:20px}
.cta-form input:focus,.cta-form select:focus,.cta-form textarea:focus{border-color:var(--yellow)}
.cta-form select option{background:var(--bg-3)}
.cta-form .btn{width:100%}
.cta-contact{display:flex;justify-content:center;gap:38px;margin-top:30px;flex-wrap:wrap;color:var(--text-2);font-size:15px}
.cta-contact a{color:var(--yellow);font-size:20px;font-weight:800;display:flex;align-items:center;gap:9px}
.cta-contact span{display:flex;align-items:center;gap:8px}
.cta-taobao i{width:8px;height:8px;border-radius:50%;background:var(--yellow)}

/* ---------- 页脚 ---------- */
.footer{background:#0a0d10;padding:64px 0 0;border-top:1px solid var(--line)}
.footer-inner{display:grid;grid-template-columns:1.6fr 1fr 1fr 1.4fr;gap:40px;padding-bottom:48px}
.f-brand{display:flex;gap:14px}
.f-brand strong{font-size:18px;letter-spacing:1px}
.f-brand p{color:var(--text-3);font-size:13px;margin-top:6px}
.f-col h4{font-size:15px;margin-bottom:16px;color:#fff}
.f-col a,.f-col span{display:block;color:var(--text-3);font-size:13.5px;margin-bottom:10px;transition:.2s}
.f-col a:hover{color:var(--yellow)}
.copyright{border-top:1px solid var(--line);padding:20px 24px;text-align:center;color:var(--text-3);font-size:12.5px}

/* ---------- 移动端悬浮条 ---------- */
.mobile-bar{display:none}

/* ---------- 滚动显现 ---------- */
.reveal{opacity:0;transform:translateY(34px);transition:opacity .7s ease,transform .7s ease}
.reveal.in{opacity:1;transform:none}

/* ============================================================
   响应式
   ============================================================ */
@media (max-width:1024px){
  .nav-tel{display:none}
  .biz-grid{gap:18px}
  .case-grid{min-height:480px}
  .hero-title{font-size:44px}
}
@media (max-width:768px){
  .container{padding:0 18px}
  .hide-m{display:none}
  .nav-inner{gap:12px}
  .menu{
    position:fixed;top:var(--nav-h);left:0;right:0;background:rgba(13,16,20,.98);
    flex-direction:column;gap:0;padding:10px 18px 24px;border-bottom:1px solid var(--line);
    transform:translateY(-130%);transition:.35s;
  }
  .menu.open{transform:translateY(0)}
  .menu a{padding:15px 6px;border-bottom:1px solid var(--line);border-radius:0;font-size:16px}
  .menu-cta{margin-top:14px;text-align:center;border-radius:6px}
  .nav-burger{display:flex}
  .menu.open~.nav-burger span:nth-child(1){transform:translateY(7px) rotate(45deg)}
  .menu.open~.nav-burger span:nth-child(2){opacity:0}
  .menu.open~.nav-burger span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}

  .hero{min-height:auto;padding:130px 0 80px}
  .hero-title{font-size:33px;letter-spacing:1px}
  .hero-sub{font-size:15px}
  .hero-trust{gap:14px 22px;margin-top:38px}
  .btn{height:46px;padding:0 22px;font-size:15px;width:100%}
  .hero-btns{flex-direction:column}

  .section{padding:64px 0}
  .sec-head{margin-bottom:38px}
  .sec-head h2,.cta-inner h2{font-size:27px}
  .sec-head-row{flex-direction:column;align-items:flex-start;gap:14px}

  .biz-grid{grid-template-columns:1fr}
  .biz-body p{min-height:0}

  .case-grid{grid-template-columns:1fr;grid-template-rows:none;min-height:0}
  .case-card{min-height:280px}
  .case-lg{min-height:340px}
  .case-info p{max-height:80px;opacity:1}

  .adv-grid{grid-template-columns:1fr 1fr;gap:14px}
  .adv-item{padding:26px 16px}
  .adv-item p{font-size:13px}
  .stats{grid-template-columns:1fr 1fr}
  .stat:nth-child(3){border-left:none}
  .stat:nth-child(3),.stat:nth-child(4){border-top:1px solid var(--line)}
  .stat strong{font-size:36px}

  .timeline{grid-template-columns:1fr}
  .tl-pay{position:static;display:inline-block;margin-top:14px}

  .about-grid{grid-template-columns:1fr;gap:34px}
  .about-txt h2{font-size:27px}

  .form-row{grid-template-columns:1fr}
  .cta-form{padding:20px}
  .cta-contact{flex-direction:column;gap:14px}

  .footer-inner{grid-template-columns:1fr 1fr;gap:30px}
  .f-brand{grid-column:1/-1}

  body{padding-bottom:64px}
  .mobile-bar{
    display:grid;grid-template-columns:1fr 1fr 1.6fr;position:fixed;left:0;right:0;bottom:0;z-index:90;
    height:60px;background:rgba(10,13,16,.96);border-top:1px solid var(--line);backdrop-filter:blur(10px)
  }
  .mobile-bar a{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:3px;font-size:12px;color:var(--text-2)}
  .mobile-bar .ico-phone{width:18px;height:18px}
  .mobile-bar .ico-wechat{width:19px;height:19px}
  .mobile-bar .mb-form{background:var(--yellow);color:#1a1400;font-size:15px;font-weight:700}
}
@media (max-width:420px){
  .hero-title{font-size:29px}
  .adv-grid{grid-template-columns:1fr}
  .footer-inner{grid-template-columns:1fr}
}