:root {
  --c-primary: #0052CC;        /* 商务蓝 — 主色：信任 / 专业 */
  --c-primary-dark: #003d99;
  --c-ink: #1A1A1A;            /* 科技黑 */
  --c-bg: #F4F5F7;             /* 浅灰背景 — 留白 */
  --c-white: #FFFFFF;
  --c-muted: #5b6776;
  --c-line: #e3e8ef;
  --c-accent: #FF5630;         /* 橘红 — CTA 转化 */
  --c-accent-dark: #e0441f;
  --c-green: #36B37E;          /* 环保绿 — 备用 CTA */
  --max: 1180px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "Segoe UI", "Helvetica Neue", Arial, system-ui, sans-serif;
  color: var(--c-ink);
  background: var(--c-bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--c-primary); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; }

/* Header / Nav */
header.site {
  background: #000;
  color: #fff;
  position: sticky; top: 0; z-index: 50;
  box-shadow: 0 2px 10px rgba(0,0,0,.12);
}
.nav-inner {
  max-width: var(--max); margin: 0 auto; padding: 0 20px;
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.brand { display: flex; align-items: center; }
.brand img { height: 40px; width: auto; display: block; }
nav.main ul {
  list-style: none; display: flex; gap: 18px; margin: 0; padding: 0;
  font-size: 14px; flex-wrap: wrap;
}
nav.main a { color: #dce6f2; white-space: nowrap; }
nav.main a:hover { color: #fff; text-decoration: none; }
.nav-toggle {
  display: none; background: none; border: 1px solid #fff; color: #fff;
  border-radius: 6px; padding: 6px 10px; cursor: pointer; font-size: 13px;
}

/* Dropdown nav */
nav.main li.has-dropdown { position: relative; }
nav.main .caret { font-size: 10px; opacity: .85; margin-left: 2px; }
nav.main .dropdown {
  display: none; position: absolute; top: 100%; left: 0;
  background: #000; min-width: 244px; padding: 8px 0;
  box-shadow: 0 12px 30px rgba(0,0,0,.30); z-index: 60;
  flex-direction: column; gap: 0; border-radius: 0 0 10px 10px;
}
nav.main li.has-dropdown:hover .dropdown,
nav.main li.has-dropdown:focus-within .dropdown { display: flex; }
nav.main .dropdown li { padding: 0; }
nav.main .dropdown a { display: block; padding: 10px 20px; white-space: nowrap; color: #dce6f2; }
nav.main .dropdown a:hover { background: #111; color: #fff; text-decoration: none; }

/* Spec table */
.spec-table { width: 100%; border-collapse: collapse; background: #fff; }
.spec-table th, .spec-table td { text-align: left; padding: 12px 14px; border-bottom: 1px solid var(--c-line); font-size: 14px; vertical-align: top; }
.spec-table th { width: 220px; color: var(--c-primary); font-weight: 700; }
.spec-table tr:last-child td, .spec-table tr:last-child th { border-bottom: none; }
.table-wrap { overflow-x: auto; margin: 16px 0; border-radius: 12px; border: 1px solid var(--c-line); }
.sub { font-size: 20px; margin: 30px 0 14px; color: var(--c-ink); letter-spacing: -.2px; }
.cmp-table { width: 100%; border-collapse: collapse; background: #fff; font-size: 14px; margin-bottom: 6px; }
.cmp-table th, .cmp-table td { border: 1px solid var(--c-line); padding: 10px 12px; text-align: left; vertical-align: top; }
.cmp-table thead th { background: var(--c-primary); color: #fff; font-weight: 700; }
.cmp-table tbody th { color: var(--c-primary); font-weight: 700; width: 190px; background: #f5f8fd; }

/* Video embed placeholder */
.video-embed { position: relative; width: 100%; aspect-ratio: 16 / 9; background: #0b1020; border-radius: 12px; overflow: hidden; }
.video-placeholder { position: absolute; inset: 0; display: flex; flex-direction: column; align-items: center; justify-content: center; color: #aab4c0; gap: 10px; text-align: center; padding: 20px; }
.video-placeholder .play { font-size: 54px; color: var(--c-accent); line-height: 1; }
.video-embed iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }

/* Hero */
.hero {
  background: linear-gradient(135deg, var(--c-primary), var(--c-primary-dark));
  color: #fff; padding: 72px 20px;
}
.hero-inner { max-width: var(--max); margin: 0 auto; }
.hero h1 { font-size: 40px; margin: 0 0 10px; line-height: 1.18; letter-spacing: -.5px; }
.hero-sub { font-size: 16px; font-weight: 700; letter-spacing: 1.5px; text-transform: uppercase; color: var(--c-accent); margin: 0 0 16px !important; }
.hero p { font-size: 18px; max-width: 720px; color: #e3ebf7; }
.cta {
  display: inline-block; margin-top: 22px;
  background: var(--c-accent); color: #fff; font-weight: 700;
  padding: 13px 24px; border-radius: 8px;
}
.cta:hover { text-decoration: none; background: var(--c-accent-dark); }

/* Layout */
.section { max-width: var(--max); margin: 0 auto; padding: 60px 20px; }
.section h2 { font-size: 28px; margin: 0 0 8px; color: var(--c-primary); letter-spacing: -.3px; }
.section .lead { color: var(--c-muted); margin: 0 0 30px; max-width: 760px; }

/* Cards grid */
.grid { display: grid; gap: 22px; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.cert-list { list-style: none; display: flex; flex-wrap: wrap; gap: 10px; padding: 0; margin: 18px 0 0; }
.cert-list li { background: #eef3fb; color: var(--c-ink); border: 1px solid #d7e2f3; border-radius: 999px; padding: 8px 16px; font-size: 14px; font-weight: 600; }
.band-light { background: #f5f8fd; border-top: 1px solid var(--c-line); border-bottom: 1px solid var(--c-line); }
.band-light h2 { color: var(--c-primary); }
.card {
  background: var(--c-white);
  border: 1px solid var(--c-line);
  border-radius: 12px; padding: 24px;
  transition: transform .15s ease, box-shadow .15s ease;
}
.card:hover { transform: translateY(-3px); box-shadow: 0 10px 28px rgba(0,82,204,.10); }
.card h3 { margin: 0 0 6px; font-size: 18px; color: var(--c-ink); }
.card .tag {
  display: inline-block; font-size: 12px; font-weight: 700;
  color: var(--c-primary); background: #e7f0fb; padding: 3px 9px; border-radius: 999px; margin-bottom: 10px;
}
.card ul { margin: 10px 0 0; padding-left: 18px; color: var(--c-muted); font-size: 14px; }
.card.new { border-color: var(--c-accent); box-shadow: 0 0 0 2px rgba(255,86,48,.18); }
a.card-link { display: block; text-decoration: none; color: inherit; }
a.card-link:hover h3 { color: var(--c-primary); }
.card-more { display: inline-block; margin-top: 12px; font-size: 13px; font-weight: 700; color: var(--c-primary); }

/* Feature rows */
.feature { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; margin: 28px 0; align-items: start; }
.feature h3 { color: var(--c-primary); margin: 0 0 8px; }
.feature .kpis { display: flex; gap: 18px; flex-wrap: wrap; margin-top: 14px; }
.kpi { background: #e7f0fb; border-radius: 10px; padding: 12px 16px; }
.kpi b { display: block; font-size: 22px; color: var(--c-primary); }
.kpi span { font-size: 12px; color: var(--c-muted); }

/* FAQ */
.faq-item { background: var(--c-white); border: 1px solid var(--c-line); border-radius: 10px; padding: 18px 20px; margin-bottom: 14px; }
.faq-item h3 { margin: 0 0 8px; font-size: 17px; color: var(--c-ink); }
.faq-item p { margin: 0; color: var(--c-ink); }

/* CTA band */
.band { background: var(--c-ink); color: #fff; padding: 48px 20px; text-align: center; }
.band-inner { max-width: 820px; margin: 0 auto; }
.band h2 { color: #fff; font-size: 26px; margin: 0 0 8px; }
.band p { color: #c9d2dd; margin: 0 0 18px; }
.band-actions { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; margin-bottom: 14px; }
.btn-cta { background: var(--c-accent); color: #fff; font-weight: 700; padding: 13px 26px; border-radius: 8px; display: inline-block; }
.btn-cta:hover { background: var(--c-accent-dark); text-decoration: none; }
.btn-ghost { background: transparent; color: #fff; font-weight: 700; padding: 12px 24px; border-radius: 8px; border: 1px solid #fff; display: inline-block; }
.btn-ghost:hover { background: rgba(255,255,255,.12); text-decoration: none; }
.band-mail a { color: #fff; text-decoration: underline; }

/* Footer */
footer.site { background: var(--c-ink); color: #aab4c0; padding: 48px 20px 28px; font-size: 14px; }
.footer-inner { max-width: var(--max); margin: 0 auto; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1.2fr; gap: 30px; }
.footer-col h4 { color: #fff; font-size: 15px; margin: 0 0 12px; }
.footer-col ul { list-style: none; margin: 0; padding: 0; }
.footer-col li { margin: 7px 0; color: #aab4c0; }
.footer-col a { color: #cdd6e0; }
.footer-col a:hover { color: #fff; }
.footer-about { color: #aab4c0; font-size: 13px; margin: 0 0 14px; max-width: 320px; }
.cert-badges { display: flex; gap: 8px; flex-wrap: wrap; }
.cert-badges span {
  display: inline-block; font-size: 11px; font-weight: 700; letter-spacing: .5px;
  color: #fff; background: #2b3440; border: 1px solid #3c4856;
  padding: 5px 10px; border-radius: 6px;
}
.footer-copy { border-top: 1px solid #2b3440; margin-top: 28px; padding-top: 18px; color: #7e8a98; font-size: 13px; text-align: center; }

/* Inquiry form (Contact page) */
.inquiry {
  background: var(--c-white); border: 1px solid var(--c-line); border-radius: 14px;
  padding: 32px; max-width: 720px;
}
.inquiry .field { margin-bottom: 18px; }
.inquiry label { display: block; font-weight: 600; margin-bottom: 6px; color: var(--c-ink); font-size: 14px; }
.inquiry input, .inquiry select, .inquiry textarea {
  width: 100%; padding: 11px 13px; border: 1px solid var(--c-line); border-radius: 8px;
  font-size: 14px; font-family: inherit; color: var(--c-ink); background: #fff;
}
.inquiry input:focus, .inquiry select:focus, .inquiry textarea:focus {
  outline: none; border-color: var(--c-primary); box-shadow: 0 0 0 3px rgba(0,82,204,.12);
}
.inquiry textarea { min-height: 120px; resize: vertical; }
.inquiry .submit {
  background: var(--c-accent); color: #fff; font-weight: 700; border: none;
  padding: 13px 28px; border-radius: 8px; font-size: 15px; cursor: pointer;
}
.inquiry .submit:hover { background: var(--c-accent-dark); }
.inquiry .note { font-size: 13px; color: var(--c-muted); margin-top: 10px; }

/* Contact channels */
.channels { display: grid; gap: 18px; grid-template-columns: repeat(auto-fit, minmax(220px,1fr)); margin-top: 26px; }
.channel { background: var(--c-white); border: 1px solid var(--c-line); border-radius: 12px; padding: 20px; }
.channel h3 { margin: 0 0 6px; color: var(--c-primary); font-size: 16px; }
.channel p, .channel a { font-size: 14px; color: var(--c-muted); }

/* About page */
.about-photo {
  width: 100%; height: 220px; object-fit: cover; border-radius: 12px;
  background: #dfe6ef; display: flex; align-items: center; justify-content: center;
  color: #8a97a6; font-size: 14px; border: 1px dashed var(--c-line);
}
.stat-row { display: flex; gap: 18px; flex-wrap: wrap; margin: 22px 0; }
.stat { background: #e7f0fb; border-radius: 10px; padding: 16px 20px; flex: 1; min-width: 150px; }
.stat b { display: block; font-size: 26px; color: var(--c-primary); }
.stat span { font-size: 13px; color: var(--c-muted); }
.cert-row { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 14px; }
.cert-row span {
  font-size: 12px; font-weight: 700; color: #fff; background: var(--c-primary);
  padding: 8px 14px; border-radius: 8px;
}

@media (max-width: 820px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
  nav.main ul { display: none; flex-direction: column; gap: 10px; padding: 16px 0; width: 100%; }
  .nav-toggle { display: inline-block; }
  .hero h1 { font-size: 30px; }
  .feature { grid-template-columns: 1fr; }
  nav.main .dropdown { position: static; display: block; box-shadow: none; background: #111; padding: 0 0 8px 16px; min-width: 0; border-radius: 0; }
  nav.main li.has-dropdown:hover .dropdown { display: block; }
  nav.main .dropdown a { padding: 9px 14px; }
}