:root {
  --primary: #1565d8;
  --primary-dark: #0d47a1;
  --primary-light: #e8f0fe;
  --accent: #00a8e8;
  --navy: #0d1b2a;
  --navy-2: #122a4a;
  --bg: #ffffff;
  --bg-soft: #f5f7fa;
  --text: #1a2b3c;
  --text-dim: #5b6b7b;
  --text-light: #8b98a8;
  --border: #e3e8ef;
  --radius: 10px;
  --shadow: 0 4px 20px rgba(13, 27, 42, 0.06);
  --shadow-hover: 0 12px 34px rgba(13, 27, 42, 0.12);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  background: var(--bg); color: var(--text); line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}
a { text-decoration: none; color: inherit; }
ul { list-style: none; }
img { max-width: 100%; display: block; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 22px; }

/* ===== 顶栏 ===== */
.topbar { background: var(--navy); color: #c3d0de; font-size: 13px; }
.topbar-inner { display: flex; align-items: center; justify-content: space-between; height: 38px; }
.topbar a { color: #fff; }
.topbar a:hover { color: #7fc4ff; }
.topbar .sep { margin: 0 12px; opacity: .3; }
.topbar .right { display: flex; align-items: center; gap: 4px; }

/* ===== 头部 ===== */
.site-header { position: sticky; top: 0; z-index: 200; background: #fff; box-shadow: 0 1px 0 var(--border); }
.header-main { display: flex; align-items: center; justify-content: space-between; height: 76px; }
.brand { display: flex; align-items: center; gap: 10px; }
.brand-logo { height: 44px; width: auto; }
.brand-text { line-height: 1.15; }
.brand-text b { display: block; font-size: 20px; color: var(--navy); font-weight: 800; }
.brand-text small { font-size: 11px; color: var(--text-light); letter-spacing: 2px; }

.nav { display: flex; align-items: center; gap: 2px; }
.nav > a, .nav-item > a { display: block; padding: 10px 17px; font-size: 15.5px; color: #33404f; border-radius: 6px; transition: .18s; font-weight: 500; }
.nav a:hover { color: var(--primary); }
.nav a.active { color: var(--primary); font-weight: 600; }

.has-dropdown { position: relative; }
.dropdown {
  position: absolute; top: 100%; left: 0; min-width: 210px; background: #fff;
  border: 1px solid var(--border); border-radius: 10px; box-shadow: var(--shadow-hover);
  padding: 8px 0; opacity: 0; visibility: hidden; transform: translateY(8px); transition: .2s;
}
.has-dropdown:hover .dropdown { opacity: 1; visibility: visible; transform: translateY(0); }
.dropdown a { display: block; padding: 10px 22px; font-size: 14.5px; color: #3a4858; }
.dropdown a:hover { background: var(--primary-light); color: var(--primary); }

.header-cta { margin-left: 12px; }
.menu-btn { display: none; background: none; border: none; font-size: 27px; cursor: pointer; color: var(--navy); }

/* ===== 按钮 ===== */
.btn { display: inline-block; padding: 12px 30px; border-radius: 7px; font-size: 15px; font-weight: 600; transition: .18s; cursor: pointer; border: none; }
.btn-primary { background: linear-gradient(135deg, var(--primary), var(--accent)); color: #fff; box-shadow: 0 4px 14px rgba(21,101,216,.28); }
.btn-primary:hover { box-shadow: 0 6px 20px rgba(21,101,216,.4); transform: translateY(-1px); }
.btn-ghost { background: #fff; color: var(--primary); border: 1px solid var(--primary); }
.btn-ghost:hover { background: var(--primary-light); }
.btn-sm { padding: 8px 20px; font-size: 14px; }
.btn-lg { padding: 14px 38px; font-size: 16px; }

/* ===== Hero ===== */
.hero { background: linear-gradient(135deg, var(--navy) 0%, var(--navy-2) 55%, #154a86 100%); color: #fff; overflow: hidden; }
.hero-grid { display: grid; grid-template-columns: 1.1fr .9fr; gap: 48px; align-items: center; padding: 70px 0 78px; }
.eyebrow { display: inline-block; color: #7fc4ff; font-size: 13px; font-weight: 700; letter-spacing: 2px; margin-bottom: 14px; }
.hero-text h1 { font-size: 46px; line-height: 1.22; font-weight: 800; }
.hero-text h1 .hl { color: #4db6ff; }
.hero-sub { color: #b9cde4; font-size: 16.5px; margin: 20px 0 30px; max-width: 540px; }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }
.hero-stats { display: flex; gap: 42px; margin-top: 40px; }
.hero-stats .stat b { font-size: 28px; color: #4db6ff; display: block; }
.hero-stats .stat span { font-size: 13px; color: #8fa8c4; }
.hero-visual { display: flex; justify-content: center; }
.hero-device { background: #fff; border-radius: 16px; padding: 20px; box-shadow: 0 20px 50px rgba(0,0,0,.3); }
.hero-device img { width: 100%; max-width: 400px; max-height: 360px; object-fit: contain; }

/* ===== Section ===== */
.section { padding: 72px 0; }
.section-soft { background: var(--bg-soft); }
.section-head { text-align: center; max-width: 680px; margin: 0 auto 46px; }
.section-head .kicker { color: var(--primary); font-size: 14px; font-weight: 700; letter-spacing: 2px; }
.section-head h2 { font-size: 31px; font-weight: 800; color: var(--navy); margin: 8px 0 12px; }
.section-head p { color: var(--text-dim); font-size: 15px; }

/* ===== 分类卡片 ===== */
.cat-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.cat-card { background: #fff; border: 1px solid var(--border); border-radius: 12px; padding: 32px 22px; text-align: center; transition: .2s; }
.cat-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-hover); border-color: #c4d8f5; }
.cat-icon { width: 64px; height: 64px; margin: 0 auto 16px; border-radius: 16px; background: var(--primary-light); color: var(--primary); display: grid; place-items: center; font-size: 30px; }
.cat-card h3 { font-size: 17px; color: var(--navy); margin-bottom: 8px; }
.cat-card p { font-size: 13.5px; color: var(--text-dim); }
.cat-card .more { display: inline-block; margin-top: 12px; color: var(--primary); font-size: 13.5px; font-weight: 600; }

/* ===== 产品卡片 ===== */
.prod-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.prod-card { background: #fff; border: 1px solid var(--border); border-radius: 12px; overflow: hidden; transition: .2s; display: flex; flex-direction: column; }
.prod-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-hover); }
.prod-img { height: 240px; background: #fafbfd; display: flex; align-items: center; justify-content: center; border-bottom: 1px solid var(--border); padding: 18px; overflow: hidden; }
.prod-img img { width: 100%; height: 100%; object-fit: contain; }
.prod-img-empty { font-size: 30px; font-weight: 800; color: var(--primary); letter-spacing: 1px; background: linear-gradient(135deg, #eef4fd, #e3ecf9); }
.prod-body { padding: 18px 20px 22px; display: flex; flex-direction: column; flex: 1; }
.prod-body h3 { font-size: 16.5px; color: var(--navy); margin-bottom: 8px; }
.prod-body .spec { font-size: 13px; color: var(--text-dim); margin-bottom: 16px; flex: 1; }
.prod-foot { display: flex; justify-content: space-between; align-items: center; gap: 10px; }
.prod-foot .cat-tag { font-size: 12px; color: var(--primary); background: var(--primary-light); padding: 3px 10px; border-radius: 4px; }

/* ===== 优势 ===== */
.adv-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.adv-card { background: #fff; border: 1px solid var(--border); border-radius: 12px; padding: 28px 24px; }
.adv-card .num { font-size: 34px; font-weight: 800; color: #c4d8f5; line-height: 1; margin-bottom: 10px; }
.adv-card h3 { font-size: 16px; color: var(--navy); margin-bottom: 8px; }
.adv-card p { font-size: 13.5px; color: var(--text-dim); }

/* ===== 解决方案 ===== */
.sol-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.sol-card { background: #fff; border: 1px solid var(--border); border-radius: 12px; padding: 26px 22px; transition: .2s; }
.sol-card:hover { box-shadow: var(--shadow-hover); transform: translateY(-4px); border-color: #c4d8f5; }
.sol-card .sol-icon { font-size: 34px; margin-bottom: 12px; }
.sol-card h3 { font-size: 16px; color: var(--navy); margin-bottom: 7px; }
.sol-card p { font-size: 13px; color: var(--text-dim); }

/* ===== 新闻 ===== */
.news-list li { display: flex; justify-content: space-between; gap: 18px; padding: 16px 6px; border-bottom: 1px dashed var(--border); font-size: 15px; align-items: center; }
.news-list li a { color: #33404f; transition: .15s; flex: 1; }
.news-list li a:hover { color: var(--primary); }
.news-list .date { color: var(--text-light); font-size: 13px; white-space: nowrap; }
.news-tabs { display: flex; gap: 12px; margin-bottom: 20px; }
.news-tabs span { padding: 7px 18px; border-radius: 999px; background: var(--bg-soft); font-size: 13.5px; cursor: pointer; }
.news-tabs span.on { background: var(--primary); color: #fff; }

/* ===== 关于 ===== */
.about-strip { background: #fff; border: 1px solid var(--border); border-radius: 16px; padding: 44px; display: grid; grid-template-columns: 1.2fr .8fr; gap: 36px; align-items: center; }
.about-strip h2 { font-size: 26px; color: var(--navy); margin-bottom: 14px; }
.about-strip p { color: var(--text-dim); font-size: 14.5px; margin-bottom: 10px; }
.about-strip .mini-stats { display: flex; gap: 28px; }
.about-strip .mini-stats b { font-size: 24px; color: var(--primary); display: block; }
.about-strip .mini-stats span { font-size: 12.5px; color: var(--text-dim); }

/* ===== 页头 banner ===== */
.page-banner { background: linear-gradient(120deg, var(--navy) 0%, var(--navy-2) 60%, #154a86 100%); color: #fff; padding: 50px 0; }
.page-banner h1 { font-size: 30px; font-weight: 800; }
.page-banner .crumb { font-size: 13.5px; opacity: .8; margin-top: 6px; }
.page-banner .crumb a { opacity: .85; }

/* ===== 目录 ===== */
.catalog { display: grid; grid-template-columns: 250px 1fr; gap: 28px; align-items: start; }
.cat-side { background: #fff; border: 1px solid var(--border); border-radius: 12px; padding: 10px 0; position: sticky; top: 96px; }
.cat-side h4 { padding: 12px 20px; font-size: 15px; color: var(--navy); border-bottom: 1px solid var(--border); }
.cat-side a { display: block; padding: 12px 22px; font-size: 14.5px; color: #3a4858; border-left: 3px solid transparent; transition: .15s; }
.cat-side a:hover, .cat-side a.on { color: var(--primary); border-left-color: var(--primary); background: var(--primary-light); }
.cat-main .cat-title { font-size: 21px; font-weight: 700; color: var(--navy); margin-bottom: 6px; }
.cat-main .cat-desc { color: var(--text-dim); font-size: 14px; margin-bottom: 24px; }

/* ===== 产品详情 ===== */
.pdetail { display: grid; grid-template-columns: .9fr 1.1fr; gap: 40px; align-items: start; }
.pdetail-img { background: #fff; border: 1px solid var(--border); border-radius: 14px; padding: 26px; }
.pdetail-img .main-img-wrap { display: flex; align-items: center; justify-content: center; min-height: 360px; }
.pdetail-img img.main { width: 100%; max-height: 420px; object-fit: contain; }
.pdetail-img .empty { height: 320px; display: grid; place-items: center; font-size: 40px; font-weight: 800; color: var(--primary); background: linear-gradient(135deg, #eef4fd, #e3ecf9); }
.thumbs { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 16px; }
.thumbs .thumb { width: 68px; height: 68px; object-fit: contain; background: #fafbfd; border: 2px solid var(--border); border-radius: 8px; cursor: pointer; padding: 4px; transition: .15s; }
.thumbs .thumb:hover, .thumbs .thumb.on { border-color: var(--primary); }
.pdetail-info h1 { font-size: 27px; color: var(--navy); margin-bottom: 8px; }
.pdetail-info .cat-tag { display: inline-block; background: var(--primary-light); color: var(--primary); font-size: 13px; padding: 4px 14px; border-radius: 4px; margin-bottom: 14px; }
.pdetail-info .summary { color: var(--text-dim); font-size: 15px; margin-bottom: 22px; }
.spec-table { width: 100%; border-collapse: collapse; font-size: 14px; }
.spec-table th, .spec-table td { border: 1px solid var(--border); padding: 11px 14px; text-align: left; }
.spec-table th { background: var(--bg-soft); width: 130px; color: var(--navy); }
.spec-table td { color: #3a4858; }

/* ===== 文章 ===== */
.article { max-width: 860px; margin: 0 auto; }
.article h1 { font-size: 27px; color: var(--navy); margin: 10px 0 16px; }
.article .meta { color: var(--text-light); font-size: 13px; margin-bottom: 22px; }
.article p { color: #3a4858; margin-bottom: 15px; font-size: 15.5px; }

/* ===== 联系 ===== */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; }
.contact-card { background: #fff; border: 1px solid var(--border); border-radius: 14px; padding: 30px; }
.contact-card .c-item { display: flex; gap: 14px; padding: 13px 0; border-bottom: 1px dashed var(--border); align-items: flex-start; }
.contact-card .c-item:last-child { border-bottom: none; }
.contact-card .c-icon { font-size: 21px; width: 42px; height: 42px; border-radius: 11px; background: var(--primary-light); color: var(--primary); display: grid; place-items: center; flex-shrink: 0; }
.contact-card .c-item h4 { font-size: 15px; color: var(--navy); }
.contact-card .c-item p, .contact-card .c-item a { color: var(--text-dim); font-size: 14px; word-break: break-all; }
.form-group { margin-bottom: 16px; }
.form-group label { display: block; font-size: 13.5px; margin-bottom: 6px; color: #3a4858; }
.form-group input, .form-group textarea { width: 100%; border: 1px solid var(--border); border-radius: 7px; padding: 11px 13px; font-size: 14px; font-family: inherit; }
.form-group input:focus, .form-group textarea:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(21,101,216,.12); }
.alert { padding: 13px 16px; border-radius: 8px; margin-bottom: 16px; font-size: 14px; }
.alert-success { background: #e6f7ef; color: #0a7a4b; border: 1px solid #bfe8d5; }
.alert-error { background: #fdeaea; color: #c0392b; border: 1px solid #f5c6c6; }

/* ===== 页脚 ===== */
.site-footer { background: var(--navy); color: #a9b8ca; padding: 58px 0 0; font-size: 14px; }
.footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1.3fr; gap: 34px; padding-bottom: 42px; }
.footer-grid h4 { color: #fff; font-size: 15.5px; margin-bottom: 16px; }
.footer-grid a { display: block; color: #93a5ba; padding: 4px 0; font-size: 13.5px; transition: .15s; }
.footer-grid a:hover { color: #7fc4ff; }
.footer-brand { color: #93a5ba; font-size: 13.5px; line-height: 1.9; }
.footer-brand .fb-name { color: #fff; font-size: 20px; font-weight: 800; margin-bottom: 12px; }
.footer-contact p { padding: 3px 0; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.08); padding: 20px 0; text-align: center; font-size: 13px; color: #71809420; color: #718094; }

/* ===== 响应式 ===== */
@media (max-width: 960px) {
  .nav { position: absolute; top: 76px; left: 0; right: 0; flex-direction: column; align-items: stretch; background: #fff; padding: 12px 22px; box-shadow: var(--shadow-hover); display: none; gap: 2px; }
  .nav.open { display: flex; }
  .nav > a, .nav-item > a { padding: 12px 8px; border-bottom: 1px solid var(--border); }
  .dropdown { position: static; opacity: 1; visibility: visible; transform: none; box-shadow: none; border: none; padding-left: 16px; }
  .menu-btn { display: block; }
  .header-cta { display: none; }
  .hero-grid { grid-template-columns: 1fr; padding: 44px 0 54px; }
  .hero-text h1 { font-size: 33px; }
  .hero-visual { display: none; }
  .cat-grid, .adv-grid { grid-template-columns: repeat(2, 1fr); }
  .prod-grid, .sol-grid { grid-template-columns: 1fr 1fr; }
  .about-strip, .catalog, .contact-grid, .pdetail { grid-template-columns: 1fr; }
  .cat-side { position: static; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .hero-stats { gap: 26px; }
}
@media (max-width: 560px) {
  .cat-grid, .adv-grid, .footer-grid, .prod-grid, .sol-grid { grid-template-columns: 1fr; }
}