:root {
  --color-primary: #0d3b66;
  --color-primary-dark: #082a49;
  --color-accent: #e76f22;
  --color-accent-hover: #cf5d18;
  --color-bg: #f8f9fa;
  --color-surface: #ffffff;
  --color-text: #1f2937;
  --color-muted: #6b7280;
  --color-border: #e5e7eb;
  --color-success: #047857;
  --radius: 6px;
  --shadow: 0 2px 8px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 30px rgba(0,0,0,0.08);
  --font: system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,"Noto Sans SC","Microsoft YaHei",sans-serif;
  --max-width: 1200px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0; padding: 0;
  font-family: var(--font);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--color-primary); text-decoration: none; }
a:hover { color: var(--color-accent); text-decoration: underline; }

.container { width: 92%; max-width: var(--max-width); margin: 0 auto; }

/* Header */
.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky; top: 0; z-index: 100;
}
.top-bar {
  background: var(--color-primary-dark);
  color: #cbd5e1;
  font-size: .85rem;
  padding: .4rem 0;
}
.top-bar .container { display: flex; justify-content: space-between; align-items: center; }
.top-bar a { color: #fff; }
.main-header .container {
  display: flex; align-items: center; justify-content: space-between;
  padding: .9rem 0;
}
.logo { display: flex; align-items: center; gap: .8rem; }
.logo img { max-height: 56px; width: auto; }
.brand-text { line-height: 1.2; }
.brand-text strong { font-size: 1.25rem; color: var(--color-primary); display: block; }
.brand-text span { font-size: .8rem; color: var(--color-muted); }
.main-nav { display: flex; align-items: center; gap: .2rem; }
.main-nav a {
  padding: .5rem .8rem; color: var(--color-text); font-size: .95rem; font-weight: 500;
}
.main-nav a:hover, .main-nav a.active { color: var(--color-accent); text-decoration: none; }
.nav-cta {
  background: var(--color-accent); color: #fff !important; border-radius: var(--radius);
  padding: .5rem 1rem !important;
}
.nav-cta:hover { background: var(--color-accent-hover); }
.menu-toggle {
  display: none; background: none; border: none; cursor: pointer; padding: .5rem;
}
.menu-toggle span {
  display: block; width: 24px; height: 2px; background: var(--color-primary); margin: 5px 0;
}
@media (max-width: 960px) {
  .menu-toggle { display: block; }
  .main-nav {
    display: none; position: absolute; top: 100%; left: 0; right: 0;
    background: var(--color-surface); border-bottom: 1px solid var(--color-border);
    flex-direction: column; padding: .5rem 0;
  }
  .main-nav.open { display: flex; }
  .main-nav a { width: 100%; padding: .8rem 1rem; border-bottom: 1px solid var(--color-border); }
}

/* Manual download block */
.manual-block { margin-top: 2rem; }
.manual-actions { display: flex; gap: 1rem; margin-bottom: 1rem; flex-wrap: wrap; }
.manual-block iframe { border: 1px solid var(--color-border); border-radius: var(--radius); background: #f8f9fa; }

/* Hero */
.hero {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: #fff; padding: 5rem 0 4rem;
}
.hero .container { display: grid; grid-template-columns: 1.1fr .9fr; gap: 3rem; align-items: center; }
.hero h1 { font-size: 2.6rem; line-height: 1.2; margin: 0 0 1rem; }
.hero .lead { font-size: 1.15rem; color: #dbeafe; margin-bottom: 1.8rem; max-width: 600px; }
.hero-badges { display: flex; flex-wrap: wrap; gap: .6rem; margin-bottom: 1.8rem; }
.hero-badges span {
  background: rgba(255,255,255,.12); border: 1px solid rgba(255,255,255,.2);
  padding: .35rem .8rem; border-radius: 20px; font-size: .85rem;
}
.hero-actions { display: flex; gap: 1rem; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: .4rem;
  padding: .85rem 1.6rem; border-radius: var(--radius); font-weight: 600;
  border: none; cursor: pointer; font-size: 1rem; line-height: 1;
}
.btn-primary { background: var(--color-accent); color: #fff; }
.btn-primary:hover { background: var(--color-accent-hover); text-decoration: none; color: #fff; }
.btn-outline { background: transparent; color: #fff; border: 2px solid rgba(255,255,255,.6); }
.btn-outline:hover { background: rgba(255,255,255,.1); color: #fff; text-decoration: none; }
.btn-secondary { background: var(--color-primary); color: #fff; }
.hero-img { border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-lg); }
.hero-img img { width: 100%; object-fit: cover; }
@media (max-width: 800px) {
  .hero .container { grid-template-columns: 1fr; }
  .hero h1 { font-size: 2rem; }
}

/* Sections */
.section { padding: 3.5rem 0; }
.section-title { text-align: center; margin-bottom: 2.5rem; }
.section-title h2 { font-size: 1.9rem; color: var(--color-primary); margin: 0 0 .5rem; }
.section-title p { color: var(--color-muted); margin: 0; }

/* Cards */
.card-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 1.5rem;
}
.card {
  background: var(--color-surface); border-radius: var(--radius);
  box-shadow: var(--shadow); border: 1px solid var(--color-border);
  overflow: hidden; transition: transform .15s, box-shadow .15s;
}
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); }
.card-body { padding: 1.4rem; }
.card h3 { margin: 0 0 .5rem; font-size: 1.15rem; color: var(--color-primary); }
.card p { margin: 0; color: var(--color-muted); font-size: .95rem; }
.card-img { background: #f3f4f6; aspect-ratio: 4/3; display: flex; align-items: center; justify-content: center; overflow: hidden; }
.card-img img { width: 100%; height: 100%; object-fit: cover; }
.card-footer { padding: .9rem 1.4rem; border-top: 1px solid var(--color-border); }

/* Category / product cards */
.category-card { border-left: 4px solid var(--color-accent); }
.product-card .specs {
  display: grid; grid-template-columns: 1fr 1fr; gap: .4rem .8rem;
  margin: 1rem 0; font-size: .9rem;
}
.product-card .specs span { color: var(--color-muted); }
.product-card .specs strong { color: var(--color-text); font-weight: 500; }

/* Tables */
.table-wrap { overflow-x: auto; margin: 1.5rem 0; border: 1px solid var(--color-border); border-radius: var(--radius); }
table { width: 100%; border-collapse: collapse; background: var(--color-surface); font-size: .95rem; }
th, td { padding: .7rem .9rem; text-align: left; border-bottom: 1px solid var(--color-border); }
th { background: #f1f5f9; color: var(--color-primary); font-weight: 600; }
tr:hover { background: #f8fafc; }

/* Breadcrumbs */
.breadcrumbs {
  list-style: none; display: flex; flex-wrap: wrap; gap: .4rem;
  padding: .8rem 0; margin: 0; font-size: .85rem; color: var(--color-muted);
  border-bottom: 1px solid var(--color-border);
}
.breadcrumbs li:not(:last-child)::after { content: "/"; margin-left: .4rem; color: var(--color-border); }

/* Page header */
.page-header { background: #f1f5f9; padding: 2.5rem 0; }
.page-header h1 { margin: 0; font-size: 2rem; color: var(--color-primary); }
.page-header p { margin: .5rem 0 0; color: var(--color-muted); max-width: 700px; }

/* Product detail */
.product-detail { padding: 2rem 0 4rem; }
.product-hero { display: grid; grid-template-columns: 1fr 1.2fr; gap: 2.5rem; align-items: start; margin-bottom: 2.5rem; }
.product-image { border-radius: var(--radius); border: 1px solid var(--color-border); background: #fff; padding: 1rem; }
.product-image img { width: 100%; }
.product-meta h1 { margin: 0 0 .8rem; font-size: 1.9rem; color: var(--color-primary); }
.quick-specs { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 1rem; margin: 1.2rem 0; }
.quick-spec { background: #f8fafc; border-left: 3px solid var(--color-accent); padding: .8rem; border-radius: var(--radius); }
.quick-spec dt { font-size: .8rem; color: var(--color-muted); }
.quick-spec dd { margin: .2rem 0 0; font-weight: 600; color: var(--color-text); }
@media (max-width: 800px) {
  .product-hero { grid-template-columns: 1fr; }
}

/* Article / content */
.content-block { max-width: 800px; margin: 0 auto; background: var(--color-surface); padding: 2rem; border-radius: var(--radius); box-shadow: var(--shadow); }
.content-block h2 { font-size: 1.4rem; color: var(--color-primary); margin-top: 2rem; margin-bottom: .8rem; }
.content-block h3 { font-size: 1.15rem; color: var(--color-primary-dark); margin-top: 1.5rem; }
.content-block p { margin: .8rem 0; }
.content-block ul, .content-block ol { margin: .8rem 0; padding-left: 1.4rem; }
.content-block li { margin: .3rem 0; }
.content-block blockquote {
  border-left: 4px solid var(--color-accent); background: #fff7ed;
  padding: .8rem 1rem; margin: 1rem 0; color: #7c2d12;
}

/* Selection */
.selection-grid { display: grid; grid-template-columns: 280px 1fr; gap: 2rem; align-items: start; }
.selection-sidebar { background: #fff; border: 1px solid var(--color-border); border-radius: var(--radius); padding: 1.2rem; position: sticky; top: 100px; }
.selection-sidebar label { display: block; font-size: .85rem; color: var(--color-muted); margin: .8rem 0 .3rem; }
.selection-sidebar select, .selection-sidebar input {
  width: 100%; padding: .5rem; border: 1px solid var(--color-border); border-radius: var(--radius);
}
.scenario-card { cursor: pointer; }
.scenario-card.active { border-color: var(--color-accent); box-shadow: 0 0 0 2px rgba(231,111,34,.15); }

/* FAQ */
.faq-item { background: #fff; border: 1px solid var(--color-border); border-radius: var(--radius); margin-bottom: .8rem; overflow: hidden; }
.faq-question {
  width: 100%; text-align: left; background: #f8fafc; border: none;
  padding: 1rem 1.2rem; font-size: 1rem; font-weight: 600; cursor: pointer;
  display: flex; justify-content: space-between; align-items: center;
}
.faq-answer { padding: 0 1.2rem; max-height: 0; overflow: hidden; transition: max-height .2s; }
.faq-item.open .faq-answer { padding: .5rem 1.2rem 1rem; max-height: 600px; }

/* Compare */
.compare-table th, .compare-table td { text-align: center; min-width: 160px; }
.compare-table td:first-child, .compare-table th:first-child { text-align: left; font-weight: 600; }

/* Footer */
.site-footer { background: var(--color-primary-dark); color: #cbd5e1; padding: 3rem 0 1.5rem; margin-top: 2rem; }
.footer-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 2rem; margin-bottom: 2rem; }
.footer-grid h4 { color: #fff; margin: 0 0 1rem; font-size: 1rem; }
.footer-grid ul { list-style: none; padding: 0; margin: 0; }
.footer-grid li { margin: .4rem 0; }
.footer-grid a { color: #cbd5e1; }
.quick-links { display: grid; grid-template-columns: repeat(4, 1fr); gap: .4rem .6rem; }
.quick-links li { margin: 0; }
.quick-links a { display: block; white-space: nowrap; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.1); padding-top: 1rem; font-size: .85rem; text-align: center; color: #94a3b8; }
.footer-bottom p { margin: .25rem 0; }
.footer-bottom a { color: #94a3b8; }

/* Utilities */
.text-center { text-align: center; }
.mt-2 { margin-top: 2rem; }
.mb-1 { margin-bottom: 1rem; }
.tag { display: inline-block; background: #e0f2fe; color: #075985; padding: .15rem .55rem; border-radius: 12px; font-size: .8rem; margin-right: .3rem; }