/* ============================================================
   广东钢超网 · 官网样式
   品牌色：主蓝 #1070D0 / 深海军蓝 #003050 / 浅蓝高光 #50C0F0
   ============================================================ */

:root{
  --blue:#1070D0;
  --navy:#003050;
  --sky:#50C0F0;
  --ink:#0f1c2a;
  --text:#3d4b5c;
  --muted:#7a8798;
  --line:#e3eaf2;
  --bg:#f6f9fc;
  --white:#fff;
  --radius:12px;
  --shadow:0 6px 24px rgba(0,48,80,.08);
  --shadow-lg:0 18px 44px rgba(0,48,80,.14);
  --max:1180px;
}

*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:"Microsoft YaHei","PingFang SC","Hiragino Sans GB","Source Han Sans SC",sans-serif;
  color:var(--text);
  background:var(--white);
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
}
a{text-decoration:none;color:inherit}
img{max-width:100%;display:block}
.container{max-width:var(--max);margin:0 auto;padding:0 24px}

/* ---------- 顶部导航 ---------- */
.site-header{
  position:sticky;top:0;z-index:50;
  background:rgba(255,255,255,.94);
  backdrop-filter:blur(10px);
  border-bottom:1px solid var(--line);
}
.header-inner{display:flex;align-items:center;gap:28px;height:74px}
.brand{display:flex;align-items:center;gap:10px;flex-shrink:0}
.brand-logo{height:44px;width:auto}
.brand-fallback{
  display:none;width:44px;height:44px;border-radius:10px;align-items:center;justify-content:center;
  background:linear-gradient(135deg,var(--blue),var(--navy));color:#fff;font-size:20px;font-weight:700;
}
.brand-fallback b{font-size:22px}
.brand-text{display:flex;flex-direction:column;line-height:1.25}
.brand-text strong{font-size:17px;color:var(--navy);letter-spacing:.5px}
.brand-text em{font-style:normal;font-size:11px;color:var(--muted);letter-spacing:.5px}

.nav{display:flex;gap:26px;margin-left:auto}
.nav a{font-size:15px;color:var(--text);position:relative;padding:6px 0;transition:.2s}
.nav a:hover,.nav a.active{color:var(--blue)}
.nav a.active::after{
  content:"";position:absolute;left:0;right:0;bottom:-2px;height:2px;
  background:linear-gradient(90deg,var(--blue),var(--sky));border-radius:2px;
}

.header-phone{
  display:flex;align-items:center;gap:8px;flex-shrink:0;
  background:linear-gradient(135deg,var(--blue),#0a5cae);
  color:#fff;padding:10px 18px;border-radius:999px;
  font-weight:700;font-size:15px;letter-spacing:.5px;
  box-shadow:0 6px 18px rgba(16,112,208,.28);transition:.2s;
}
.header-phone:hover{transform:translateY(-2px);box-shadow:0 10px 24px rgba(16,112,208,.38)}
.header-phone .dot{
  width:7px;height:7px;border-radius:50%;background:#66ffb2;
  box-shadow:0 0 0 4px rgba(102,255,178,.25);
}
.menu-btn{display:none;background:none;border:0;font-size:24px;color:var(--navy);cursor:pointer}

/* ---------- 首屏 ---------- */
.hero{
  position:relative;overflow:hidden;
  background:
    radial-gradient(1100px 520px at 82% -10%,rgba(80,192,240,.30),transparent 60%),
    radial-gradient(800px 420px at 8% 110%,rgba(16,112,208,.22),transparent 62%),
    linear-gradient(150deg,#002037 0%,#003050 45%,#064a80 100%);
  color:#fff;
  padding:88px 0 76px;
}
.hero::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background-image:
    linear-gradient(rgba(255,255,255,.045) 1px,transparent 1px),
    linear-gradient(90deg,rgba(255,255,255,.045) 1px,transparent 1px);
  background-size:64px 64px;
  mask-image:linear-gradient(160deg,rgba(0,0,0,.85),transparent 70%);
}
.hero-inner{position:relative;z-index:2}
.hero-tag{
  display:inline-block;font-size:13px;letter-spacing:1.5px;
  padding:7px 16px;border-radius:999px;
  background:rgba(80,192,240,.16);border:1px solid rgba(80,192,240,.45);
  color:#9fdcff;margin-bottom:26px;
}
.hero h1{
  font-size:54px;line-height:1.22;font-weight:800;letter-spacing:1px;
  margin-bottom:22px;
}
.hero h1 .hl{
  background:linear-gradient(90deg,#50C0F0,#9fdcff);
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.hero-sub{font-size:17px;color:#c2d8e8;max-width:620px;margin-bottom:36px}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap;margin-bottom:56px}

.btn{
  display:inline-flex;align-items:center;justify-content:center;
  padding:15px 34px;border-radius:999px;font-size:16px;font-weight:700;
  transition:.22s;cursor:pointer;border:1px solid transparent;
}
.btn-primary{background:linear-gradient(135deg,var(--sky),var(--blue));color:#fff;
  box-shadow:0 10px 26px rgba(80,192,240,.35)}
.btn-primary:hover{transform:translateY(-3px);box-shadow:0 16px 34px rgba(80,192,240,.48)}
.btn-ghost{border-color:rgba(255,255,255,.38);color:#fff;background:rgba(255,255,255,.05)}
.btn-ghost:hover{background:rgba(255,255,255,.14);border-color:#fff}
.btn-white{background:#fff;color:var(--navy)}
.btn-white:hover{transform:translateY(-3px);box-shadow:0 14px 30px rgba(0,0,0,.2)}

.hero-stats{display:flex;gap:56px;flex-wrap:wrap;list-style:none}
.hero-stats li{display:flex;flex-direction:column}
.hero-stats b{font-size:34px;color:#fff;line-height:1.2;font-weight:800}
.hero-stats b small{font-size:14px;font-weight:600;color:var(--sky);margin-left:2px}
.hero-stats span{font-size:13px;color:#93aec2;margin-top:4px}

/* ---------- 通用区块 ---------- */
.section{padding:88px 0}
.section-alt{background:var(--bg)}
.section-dark{background:linear-gradient(160deg,#00243d,#003050 60%,#084a7d)}
.section-dark,.section-dark h2,.section-dark h3{color:#fff}

.section-head{text-align:center;max-width:720px;margin:0 auto 52px}
.kicker{
  display:inline-block;font-size:12px;font-weight:700;letter-spacing:2.4px;
  color:var(--blue);margin-bottom:12px;
}
.section-head.light .kicker{color:var(--sky)}
.section-head h2{font-size:34px;color:var(--navy);font-weight:800;letter-spacing:1px;margin-bottom:12px}
.section-head p{font-size:15.5px;color:var(--muted)}
.section-head.light p{color:#a9c4d6}

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

/* ---------- 卡片 ---------- */
.card{
  background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  padding:32px 28px;box-shadow:var(--shadow);transition:.25s;display:block;
  position:relative;overflow:hidden;
}
.card::before{
  content:"";position:absolute;left:0;top:0;height:3px;width:0;
  background:linear-gradient(90deg,var(--blue),var(--sky));transition:.3s;
}
.card:hover{transform:translateY(-6px);box-shadow:var(--shadow-lg);border-color:#cfe3f6}
.card:hover::before{width:100%}

.product-card .card-icon{
  width:54px;height:54px;border-radius:14px;display:flex;align-items:center;justify-content:center;
  font-size:24px;color:#fff;margin-bottom:18px;
  background:linear-gradient(135deg,var(--blue),var(--navy));
  box-shadow:0 8px 20px rgba(16,112,208,.25);
}
.product-card h3{font-size:20px;color:var(--navy);margin-bottom:10px;letter-spacing:1px}
.product-card p{font-size:14.5px;color:var(--muted);min-height:46px}
.card-more{
  display:inline-block;margin-top:16px;font-size:14px;font-weight:700;color:var(--blue);
}
.card:hover .card-more{color:var(--sky)}

/* ---------- 服务优势 ---------- */
.feature{
  background:#fff;border-radius:var(--radius);padding:34px 26px;
  border:1px solid var(--line);box-shadow:var(--shadow);position:relative;transition:.25s;
}
.feature:hover{transform:translateY(-6px);box-shadow:var(--shadow-lg)}
.feature-no{
  font-size:40px;font-weight:800;line-height:1;margin-bottom:16px;
  background:linear-gradient(135deg,var(--blue),var(--sky));
  -webkit-background-clip:text;background-clip:text;color:transparent;
  opacity:.9;
}
.feature h3{font-size:17px;color:var(--navy);margin-bottom:10px}
.feature p{font-size:14.5px;color:var(--muted)}

/* ---------- 资讯 ---------- */
.news-card h3{font-size:18px;color:var(--navy);margin:14px 0 10px;line-height:1.5}
.news-card p{font-size:14.5px;color:var(--muted)}
.news-date{
  display:inline-flex;align-items:center;gap:8px;font-size:12px;
  background:rgba(16,112,208,.08);border:1px solid rgba(16,112,208,.18);
  padding:6px 14px;border-radius:999px;
}
.news-date b{color:var(--blue);font-size:13px}
.news-date span{color:var(--muted)}

/* ---------- 询价条 ---------- */
.cta-strip{
  background:linear-gradient(120deg,var(--blue),#0a5cae 55%,var(--navy));
  padding:52px 0;color:#fff;
}
.cta-inner{display:flex;align-items:center;justify-content:space-between;gap:28px;flex-wrap:wrap}
.cta-inner h2{font-size:28px;font-weight:800;letter-spacing:1px;margin-bottom:6px}
.cta-inner p{color:#bcd9f2;font-size:15px}
.cta-inner .btn-white{font-size:20px;padding:16px 40px;letter-spacing:1px}

/* ---------- 关于我们 ---------- */
.about-inner{display:grid;grid-template-columns:1.35fr 1fr;gap:56px;align-items:start}
.about-copy h2{font-size:32px;color:var(--navy);font-weight:800;margin-bottom:20px}
.about-copy p{font-size:15.5px;margin-bottom:16px;color:var(--text)}
.about-copy strong{color:var(--blue)}
.about-list{list-style:none;margin-top:24px}
.about-list li{
  position:relative;padding-left:26px;margin-bottom:12px;font-size:15px;color:var(--text);
}
.about-list li::before{
  content:"";position:absolute;left:0;top:10px;width:8px;height:8px;border-radius:2px;
  background:linear-gradient(135deg,var(--blue),var(--sky));
}
.about-side{display:flex;flex-direction:column;gap:18px}
.mini-card{
  background:var(--bg);border:1px solid var(--line);border-left:3px solid var(--blue);
  border-radius:10px;padding:22px 24px;
}
.mini-label{font-size:13px;font-weight:700;color:var(--blue);letter-spacing:1px}
.mini-card p{font-size:14.5px;color:var(--muted);margin:10px 0 14px}
.mini-badge{
  display:inline-block;font-size:12.5px;padding:5px 13px;border-radius:999px;
  background:#fff;border:1px solid var(--line);color:var(--navy);font-weight:600;
}

/* ---------- 联系我们 ---------- */
.section-dark .contact-grid{margin-top:8px}
.contact-item{
  background:rgba(255,255,255,.06);border:1px solid rgba(255,255,255,.12);
  border-radius:var(--radius);padding:36px 28px;text-align:center;transition:.25s;
}
.contact-item:hover{background:rgba(255,255,255,.11);transform:translateY(-5px)}
.contact-icon{
  width:56px;height:56px;margin:0 auto 18px;border-radius:50%;
  display:flex;align-items:center;justify-content:center;font-size:24px;color:#fff;
  background:linear-gradient(135deg,var(--sky),var(--blue));
}
.contact-item h3{font-size:16px;margin-bottom:10px;letter-spacing:1px;color:#9fdcff}
.contact-item a{font-size:26px;font-weight:800;color:#fff;letter-spacing:1px}
.contact-item a:hover{color:var(--sky)}
.contact-item p{font-size:15px;color:#c2d8e8}
.contact-item small{color:#7f9cb1;font-size:12.5px}

/* ---------- 页脚 ---------- */
.site-footer{background:#001a2c;color:#8fa7b8;padding:60px 0 0}
.footer-inner{display:grid;grid-template-columns:2fr 1fr 1fr;gap:44px;padding-bottom:44px}
.footer-brand strong{display:block;color:#fff;font-size:17px;margin-bottom:12px;letter-spacing:.5px}
.footer-brand p{font-size:14px;margin-bottom:6px}
.footer-brand .muted{color:#6d8497;font-size:13px}
.footer-links h4{color:#fff;font-size:14px;margin-bottom:16px;letter-spacing:1px}
.footer-links a{display:block;font-size:14px;color:#8fa7b8;margin-bottom:10px;transition:.2s}
.footer-links a:hover{color:var(--sky)}
.copyright{
  border-top:1px solid rgba(255,255,255,.08);padding:20px 0;
  font-size:13px;color:#5f778a;text-align:center;
}

/* ---------- 响应式 ---------- */
@media (max-width:1024px){
  .grid-4{grid-template-columns:repeat(2,1fr)}
  .grid-3{grid-template-columns:repeat(2,1fr)}
  .about-inner{grid-template-columns:1fr;gap:36px}
  .hero h1{font-size:44px}
}
@media (max-width:820px){
  .nav{
    position:absolute;top:74px;left:0;right:0;flex-direction:column;gap:0;
    background:#fff;border-bottom:1px solid var(--line);
    max-height:0;overflow:hidden;transition:.3s;box-shadow:var(--shadow);
  }
  .nav.open{max-height:420px;padding:10px 0}
  .nav a{padding:14px 24px;width:100%}
  .nav a.active::after{display:none}
  .nav a.active{background:rgba(16,112,208,.06)}
  .menu-btn{display:block}
  .header-phone .num{display:none}
  .header-phone{padding:12px 14px}
}
@media (max-width:640px){
  .grid-3,.grid-4{grid-template-columns:1fr}
  .hero{padding:64px 0 56px}
  .hero h1{font-size:34px}
  .hero-sub{font-size:15.5px}
  .hero-stats{gap:28px}
  .hero-stats b{font-size:26px}
  .section{padding:64px 0}
  .section-head h2{font-size:26px}
  .cta-inner h2{font-size:22px}
  .cta-inner .btn-white{width:100%;font-size:18px}
  .footer-inner{grid-template-columns:1fr;gap:30px}
}