/* ===== 鹏变电气有限公司官网 · 设计系统 ===== */
:root{
  --blue:#0B3D6B;        /* 主色：工业深蓝 */
  --blue-2:#12548F;      /* 次蓝 */
  --orange:#F5A623;      /* 辅助：能量橙 */
  --ink:#1F2A37;         /* 正文 */
  --gray:#6B7280;        /* 次要文字 */
  --bg:#F5F7FA;          /* 浅灰背景 */
  --white:#FFFFFF;
  --line:#E3E8EF;
  --maxw:1200px;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:"Segoe UI","Microsoft YaHei","PingFang SC",Arial,sans-serif;
  color:var(--ink);background:var(--white);line-height:1.7;
  font-size:16px;
}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
.container{max-width:var(--maxw);margin:0 auto;padding:0 20px}

/* ===== 顶部 ===== */
.topbar{background:var(--blue);color:#fff;font-size:13px}
.topbar .container{display:flex;justify-content:space-between;align-items:center;height:40px;flex-wrap:wrap;gap:8px}
.topbar a{opacity:.9}
.topbar a:hover{opacity:1}
.lang-switch button{
  background:transparent;border:1px solid rgba(255,255,255,.4);color:#fff;
  padding:3px 10px;cursor:pointer;font-size:13px;border-radius:4px;margin-left:6px
}
.lang-switch button.active{background:var(--orange);border-color:var(--orange);color:#fff;font-weight:600}

header.site{position:sticky;top:0;z-index:50;background:#fff;border-bottom:1px solid var(--line)}
.nav{display:flex;align-items:center;justify-content:space-between;height:72px}
.logo{display:flex;align-items:center;gap:12px;font-weight:700;color:var(--blue);font-size:20px}
.logo img{height:50px;width:auto;display:block}
.logo .mark{
  width:42px;height:42px;border-radius:8px;background:var(--blue);color:#fff;
  display:flex;align-items:center;justify-content:center;font-size:20px;font-weight:800;letter-spacing:-1px
}
.logo small{display:block;font-size:11px;color:var(--gray);font-weight:400;letter-spacing:1px}
.menu{display:flex;gap:28px;list-style:none;font-size:15px}
.menu a{color:var(--ink);padding:6px 0;position:relative;font-weight:500}
.menu a:hover{color:var(--blue)}
.menu a.active{color:var(--blue);font-weight:700}
.hamburger{display:none;background:none;border:0;font-size:26px;cursor:pointer;color:var(--blue)}

/* ===== 语言显示控制 ===== */
body.lang-zh .en{display:none}
body.lang-en .zh{display:none}

/* ===== Hero ===== */
.hero{
  background:linear-gradient(120deg,var(--blue) 0%,var(--blue-2) 100%);
  color:#fff;padding:80px 0;position:relative;overflow:hidden;
  background-size:cover;background-position:center
}
.hero-home{
  background-image:linear-gradient(120deg,rgba(11,61,107,.92) 0%,rgba(18,84,143,.85) 100%),url('../assets/cover.jpg')
}
.hero-products{
  background-image:linear-gradient(120deg,rgba(11,61,107,.92) 0%,rgba(18,84,143,.85) 100%),url('../assets/product-catalog.jpg')
}
.hero::after{
  content:"";position:absolute;right:-100px;top:-60px;width:420px;height:420px;
  background:radial-gradient(circle,rgba(245,166,35,.25),transparent 60%);border-radius:50%
}
.hero h1{font-size:44px;line-height:1.2;margin-bottom:18px;font-weight:800}
.hero p{font-size:18px;max-width:620px;opacity:.92;margin-bottom:30px}
.btn{
  display:inline-block;padding:13px 30px;border-radius:6px;font-weight:600;font-size:16px;
  transition:.2s;cursor:pointer;border:0
}
.btn-primary{background:var(--orange);color:#fff}
.btn-primary:hover{background:#e09614}
.btn-ghost{background:transparent;border:1px solid rgba(255,255,255,.6);color:#fff;margin-left:12px}
.btn-ghost:hover{background:rgba(255,255,255,.12)}

/* ===== 区块通用 ===== */
section{padding:70px 0}
.section-title{text-align:center;margin-bottom:46px}
.section-title h2{font-size:32px;color:var(--blue);margin-bottom:10px}
.section-title .sub{color:var(--gray)}
.bg-gray{background:var(--bg)}

/* ===== 数据条 ===== */
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:20px;margin-top:40px}
.stat{background:#fff;border:1px solid var(--line);border-radius:10px;padding:26px 18px;text-align:center}
.stat .num{font-size:34px;font-weight:800;color:var(--orange)}
.stat .label{color:var(--gray);font-size:14px;margin-top:6px}

/* ===== 卡片网格 ===== */
.grid{display:grid;gap:24px}
.grid-3{grid-template-columns:repeat(3,1fr)}
.grid-4{grid-template-columns:repeat(4,1fr)}
.grid-7{grid-template-columns:repeat(4,1fr)}
.card{background:#fff;border:1px solid var(--line);border-radius:12px;padding:28px;transition:.2s}
.card:hover{box-shadow:0 10px 30px rgba(11,61,107,.10);transform:translateY(-3px);border-color:var(--blue-2)}
.card h3{color:var(--blue);font-size:19px;margin-bottom:10px}
.card h3 a{color:var(--blue);text-decoration:none}
.card h3 a:hover{text-decoration:underline}
.card .ico{width:48px;height:48px;border-radius:10px;background:var(--bg);color:var(--blue);
  display:flex;align-items:center;justify-content:center;font-size:22px;margin-bottom:14px;font-weight:700}
.card p{color:var(--gray);font-size:15px}

/* 产品卡 */
.product-card .ph{width:100%;height:170px;border-radius:8px;margin-bottom:16px;background:var(--bg);
  display:flex;align-items:center;justify-content:center;color:var(--gray);font-size:14px;border:1px dashed var(--line)}
.product-card .tags{margin-top:14px;display:flex;flex-wrap:wrap;gap:8px}
.tag{background:var(--bg);color:var(--blue-2);font-size:12px;padding:4px 10px;border-radius:20px}

/* ===== 应用领域 ===== */
.apps{display:flex;flex-wrap:wrap;gap:12px;justify-content:center}
.app{background:#fff;border:1px solid var(--line);border-radius:30px;padding:10px 22px;font-size:15px;color:var(--ink)}

/* ===== 联系 ===== */
.contact-wrap{display:grid;grid-template-columns:1fr 1fr;gap:40px}
.contact-info li{list-style:none;margin-bottom:16px;display:flex;gap:12px;align-items:flex-start}
.contact-info .k{color:var(--blue);font-weight:600;min-width:70px}
.form input,.form textarea{width:100%;padding:12px 14px;border:1px solid var(--line);border-radius:8px;
  margin-bottom:14px;font-size:15px;font-family:inherit}
.form textarea{resize:vertical;min-height:120px}
.form .btn{width:100%}

/* ===== 页脚 ===== */
footer.site{background:var(--blue);color:#cdd9e6;padding:46px 0 26px}
footer .cols{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:30px}
footer h4{color:#fff;font-size:16px;margin-bottom:14px}
footer a{color:#cdd9e6;font-size:14px;display:block;margin-bottom:8px}
footer a:hover{color:#fff}
footer .copy{border-top:1px solid rgba(255,255,255,.15);margin-top:30px;padding-top:18px;font-size:13px;text-align:center;opacity:.8}

/* ===== 占位图样式 ===== */
.ph-block{background:var(--bg);border:1px dashed var(--line);border-radius:10px;display:flex;
  align-items:center;justify-content:center;color:var(--gray);text-align:center;padding:20px;font-size:14px}
.ph-banner{height:340px}
.ph-about{height:360px}

/* ===== 响应式 ===== */
@media(max-width:900px){
  .grid-3,.grid-4,.grid-7,.stats{grid-template-columns:repeat(2,1fr)}
  .contact-wrap{grid-template-columns:1fr}
  footer .cols{grid-template-columns:1fr 1fr}
  .hero h1{font-size:32px}
  .hero p{font-size:16px}
}
@media(max-width:600px){
  .menu{position:absolute;top:72px;left:0;right:0;background:#fff;flex-direction:column;
    gap:0;padding:10px 20px;box-shadow:0 8px 20px rgba(0,0,0,.08);display:none}
  .menu.open{display:flex}
  .menu li{border-bottom:1px solid var(--line);padding:10px 0}
  .hamburger{display:block}
  .grid-3,.grid-4,.grid-7,.stats{grid-template-columns:1fr}
  footer .cols{grid-template-columns:1fr}
  .hero{padding:54px 0}
}