:root {
  color-scheme: light;
  --ink: #14202a;
  --muted: #5b6671;
  --line: #d8dee6;
  --paper: #f7f8f9;
  --white: #ffffff;
  --violet: #5b2477;
  --teal: #007c89;
  --blue: #155e9f;
  --amber: #b57a1c;
  --shadow: 0 20px 50px rgba(15, 32, 42, .12);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "Inter", "Noto Sans SC", "Microsoft YaHei", Arial, sans-serif;
  color: var(--ink);
  background: var(--white);
  line-height: 1.65;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 30;
  display: flex;
  align-items: center;
  gap: 24px;
  min-height: 76px;
  padding: 0 40px;
  background: rgba(255, 255, 255, .94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  letter-spacing: 0;
}

.brand img { width: 42px; height: 42px; object-fit: contain; }

.site-nav {
  display: flex;
  align-items: stretch;
  gap: 2px;
  flex: 1;
}

.nav-group { position: relative; }

.nav-trigger {
  display: inline-flex;
  align-items: center;
  height: 76px;
  border: 0;
  background: transparent;
  padding: 0 12px;
  color: var(--ink);
  font: inherit;
  font-size: 14px;
  cursor: pointer;
  text-decoration: none;
}

.nav-menu {
  position: absolute;
  left: 0;
  top: 76px;
  min-width: 230px;
  display: none;
  padding: 8px;
  background: var(--white);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.nav-menu a {
  display: block;
  padding: 11px 12px;
  border-radius: 6px;
  color: var(--muted);
  font-size: 14px;
}

.nav-menu a:hover { background: var(--paper); color: var(--ink); }
.nav-group:hover .nav-menu, .nav-group:focus-within .nav-menu { display: block; }

.header-cta,
.lang-switch,
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 18px;
  border-radius: 6px;
  border: 1px solid transparent;
  font-weight: 700;
  font-size: 14px;
  white-space: nowrap;
}

.header-cta,
.btn.primary {
  background: var(--ink);
  color: var(--white);
}

.lang-switch {
  border-color: var(--line);
  color: var(--ink);
  background: var(--white);
}

.btn.ghost {
  border-color: rgba(255,255,255,.72);
  color: var(--white);
}

.menu-toggle { display: none; }

.home-hero,
.page-hero {
  position: relative;
  min-height: 74vh;
  display: flex;
  align-items: center;
  padding: 96px 7vw;
  color: var(--white);
  background-image: linear-gradient(90deg, rgba(13, 22, 28, .86), rgba(13, 22, 28, .54), rgba(13, 22, 28, .18)), var(--hero-image);
  background-size: cover;
  background-position: center;
}

.page-hero { min-height: 56vh; }

.hero-content {
  width: min(760px, 100%);
}

.eyebrow {
  margin: 0 0 14px;
  color: #b8edf0;
  font-size: 13px;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0;
}

h1, h2, h3, p { margin-top: 0; }
h1, h2, h3, p, li { overflow-wrap: break-word; }

h1 {
  margin-bottom: 22px;
  font-size: clamp(38px, 6vw, 76px);
  line-height: 1.08;
  letter-spacing: 0;
}

.page-hero h1 { font-size: clamp(34px, 5vw, 60px); }

.lead {
  max-width: 720px;
  color: rgba(255,255,255,.9);
  font-size: 20px;
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 30px;
}

.section {
  padding: 86px 7vw;
}

.section:nth-of-type(even) { background: var(--paper); }

.section-head {
  max-width: 860px;
  margin-bottom: 30px;
}

h2 {
  font-size: clamp(28px, 4vw, 46px);
  line-height: 1.18;
  margin-bottom: 14px;
  letter-spacing: 0;
}

.section-head p,
.split-section p,
.note-section p,
.contact-grid p {
  color: var(--muted);
  font-size: 18px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.feature-card,
.step,
.contact-card {
  min-height: 210px;
  padding: 24px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 6px 20px rgba(15, 32, 42, .05);
}

.feature-card h3,
.step h3,
.contact-card h3 {
  margin-bottom: 10px;
  font-size: 20px;
  line-height: 1.28;
}

.feature-card p,
.step p {
  color: var(--muted);
}

.feature-card:hover {
  border-color: rgba(0, 124, 137, .55);
  transform: translateY(-2px);
  transition: .2s ease;
}

.card-link {
  display: inline-block;
  margin-top: 8px;
  color: var(--teal);
  font-weight: 800;
}

.split-section {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, .82fr);
  gap: 42px;
  align-items: center;
}

.clean-list,
.checklist {
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
}

.clean-list li,
.checklist li {
  position: relative;
  margin: 12px 0;
  padding-left: 26px;
  color: var(--muted);
}

.clean-list li::before,
.checklist li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .78em;
  width: 9px;
  height: 9px;
  background: var(--teal);
}

.media-panel {
  margin: 0;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
  box-shadow: var(--shadow);
}

.media-panel img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.media-panel figcaption {
  padding: 12px 16px;
  color: var(--muted);
  font-size: 14px;
}

.system-panel {
  min-height: 320px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 34px;
  color: var(--white);
  background: #20313b;
  border-radius: 8px;
}

.system-panel span { color: #b8edf0; font-weight: 800; }
.system-panel strong { max-width: 420px; font-size: 34px; line-height: 1.15; }

.process-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.step span {
  display: inline-flex;
  margin-bottom: 24px;
  color: var(--amber);
  font-weight: 900;
}

.checklist-section { background: #eef5f5; }

.checklist {
  columns: 2;
  column-gap: 44px;
}

.checklist li {
  break-inside: avoid;
}

.note-section {
  background: #fff8ec;
  border-top: 1px solid #ead7b9;
  border-bottom: 1px solid #ead7b9;
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 420px;
  gap: 28px;
  align-items: start;
}

.contact-card {
  min-height: auto;
  display: grid;
  gap: 10px;
}

.contact-card a { color: var(--blue); font-weight: 800; }

.site-footer {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 34px;
  padding: 54px 7vw;
  color: rgba(255,255,255,.78);
  background: #14202a;
}

.site-footer img { width: 52px; height: 52px; object-fit: contain; background: white; border-radius: 6px; margin-bottom: 16px; }
.site-footer h2 { color: white; font-size: 16px; }
.site-footer a, .site-footer span { display: block; margin: 7px 0; }

@media (max-width: 1080px) {
  .feature-grid,
  .process-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .site-header { padding: 0 22px; gap: 14px; }
  .nav-trigger { padding: 0 8px; font-size: 13px; }
}

@media (max-width: 820px) {
  .site-header {
    max-width: 100vw;
    justify-content: space-between;
    padding: 0 20px;
  }
  .brand { flex: 0 0 auto; }
  .menu-toggle {
    display: inline-flex;
    margin-left: 0;
    border: 1px solid var(--line);
    border-radius: 6px;
    background: white;
    padding: 8px 10px;
  }
  .site-nav {
    position: fixed;
    left: 0;
    right: 0;
    top: 76px;
    display: none;
    flex-direction: column;
    max-height: calc(100vh - 76px);
    overflow: auto;
    padding: 12px 20px 22px;
    background: white;
    border-bottom: 1px solid var(--line);
  }
  .site-nav.open { display: flex; }
  .nav-trigger { width: 100%; height: 44px; text-align: left; }
  .nav-menu {
    position: static;
    display: block;
    min-width: 0;
    box-shadow: none;
    border: 0;
    padding: 0 0 10px 14px;
  }
  .header-cta { display: none; }
  .lang-switch { min-height: 34px; padding: 0 12px; }
  .home-hero, .page-hero {
    min-height: 68vh;
    width: 100%;
    max-width: 100vw;
    overflow: hidden;
    padding: 72px 20px;
  }
  .hero-content { width: 100%; max-width: calc(100vw - 40px); }
  h1, .page-hero h1 { font-size: 34px; line-height: 1.12; }
  h2 { font-size: 30px; }
  html[lang="zh-CN"] h1,
  html[lang="zh-CN"] h2 { word-break: break-all; }
  html[lang="en"] h1,
  html[lang="en"] h2 { word-break: normal; overflow-wrap: normal; }
  .lead { font-size: 18px; }
  .section { padding: 58px 22px; }
  .feature-grid,
  .process-grid,
  .split-section,
  .contact-grid,
  .site-footer {
    grid-template-columns: 1fr;
  }
  .checklist { columns: 1; }
}