:root {
  --bg: #151515;
  --bg-2: #1c1c1c;
  --bg-3: #242424;
  --panel: #323232;
  --red: #cb2f20;
  --red-hover: #f5372f;
  --red-band: #6b241c;
  --white: #fff;
  --muted: #888;
  --sub: #828282;
  --line: #444;
  --text: #ddd;
  --max: 1120px;
  --header-h: 86px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  background: var(--bg);
  scroll-behavior: smooth;
  scroll-padding-top: 96px;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  line-height: 1.6;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "微软雅黑", Arial, sans-serif;
  font-size: 16px;
  min-width: 320px;
  overflow-x: hidden;
}

img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
button, input, select, textarea { color: inherit; font: inherit; }
ul { list-style: none; }

.container {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 24px;
}

.skip-link {
  position: absolute;
  left: 12px;
  top: -80px;
  z-index: 200;
  background: var(--red);
  color: #fff;
  padding: 10px 14px;
}
.skip-link:focus { top: 12px; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: rgba(21, 21, 21, .94);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid #2a2a2a;
}
.header-inner {
  display: flex;
  align-items: center;
  min-height: var(--header-h);
  gap: 18px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}
.logo-icon { width: 38px; height: 38px; }
.logo-copy { display: flex; flex-direction: column; line-height: 1.05; }
.logo-copy strong { color: #fff; font-size: 18px; font-weight: 700; }
.logo-copy small { color: #9a9a9a; font-size: 11px; margin-top: 3px; letter-spacing: .04em; }

.nav-toggle {
  display: none;
  margin-left: auto;
  width: 44px;
  height: 44px;
  border: 0;
  background: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  cursor: pointer;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: #fff;
}
.main-nav { margin-left: auto; }
.main-nav ul { display: flex; align-items: center; gap: 4px; }
.main-nav a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 12px;
  color: #cfcfcf;
  font-size: 14px;
}
.main-nav a:hover,
.main-nav a.active { color: #fff; }

.lang {
  position: relative;
  width: 96px;
  flex-shrink: 0;
}
.lang-title {
  height: 28px;
  line-height: 26px;
  padding: 0 8px 0 10px;
  border: 1px solid var(--line);
  color: #ddd;
  font-size: 12px;
  cursor: pointer;
}
.lang-title::after { content: "▾"; margin-left: 8px; }
.lang-group {
  display: none;
  position: absolute;
  left: 0;
  right: 0;
  background: var(--panel);
  border: 1px solid var(--line);
  border-top: 0;
  z-index: 5;
}
.lang.open .lang-group,
.lang:hover .lang-group { display: block; }
.lang-group a {
  display: block;
  padding: 8px 10px;
  color: #ddd;
  font-size: 12px;
}
.lang-group a:hover { background: #2c2c2c; }

.header-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  padding: 0 16px;
  background: var(--red);
  color: #fff !important;
  border-radius: 6px;
  font-size: 14px;
  white-space: nowrap;
}
.header-cta:hover { background: var(--red-hover); }

.hero {
  position: relative;
  overflow: hidden;
  background: #1a1a1a;
}
.hero-band {
  position: absolute;
  left: 0;
  right: 0;
  top: 58%;
  height: 168px;
  background: linear-gradient(180deg, #7a2b22 0%, var(--red-band) 100%);
  pointer-events: none;
}
.hero-layout {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 320px 1fr;
  align-items: start;
  min-height: 560px;
  padding: 36px 0 20px;
}
.hero-copy { padding-top: 28px; }
.hero h1 {
  color: #fff;
  font-size: 42px;
  font-weight: 700;
  line-height: 1.15;
  min-height: 55px;
}
.hero-sub {
  color: var(--sub);
  font-size: 28px;
  margin: 8px 0 28px;
}
.download-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  width: 284px;
  height: 40px;
  background: var(--red);
  color: #fff;
  border-radius: 6px;
  font-size: 16px;
  transition: background .3s;
}
.download-btn:hover { background: var(--red-hover); }
.download-btn svg { width: 18px; height: 18px; }
.download-tip {
  color: var(--muted);
  font-size: 14px;
  margin: 8px 0 28px;
}
.page-updated {
  color: #8d8d8d;
  font-size: 14px;
  margin-top: 12px;
}
.qr-block { min-height: 220px; }
.qr-frame {
  display: inline-block;
  padding: 10px;
  background: #fff;
}
.qr-frame img,
.qr-frame canvas,
.qr-frame table { display: block; }
.qr-caption,
.provider-toggle {
  color: #fff;
  font-size: 16px;
  padding: 8px 0 0 6px;
  cursor: pointer;
}
.site-provider { position: relative; display: inline-block; }
.provider-content {
  display: none;
  position: absolute;
  top: 32px;
  left: 0;
  min-width: 140px;
  background: rgba(61, 61, 61, .92);
  box-shadow: 0 8px 16px rgba(0, 0, 0, .2);
  z-index: 3;
}
.site-provider.open .provider-content,
.site-provider:hover .provider-content { display: block; }
.provider-content a {
  display: block;
  padding: 12px 16px;
  color: #d3d3d3;
  font-size: 14px;
}
.provider-content a:hover { background: rgba(203, 46, 32, .8); color: #fff; }
.hero-visual {
  display: flex;
  justify-content: flex-end;
  align-items: flex-end;
  min-width: 0;
}
.hero-visual img { width: min(100%, 640px); }

.benefit {
  background: var(--bg);
  padding: 72px 0 80px;
}
.benefit-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  text-align: center;
}
.benefit-item img {
  width: 64px;
  height: 64px;
  margin: 0 auto 18px;
}
.benefit-title { color: #fff; font-size: 20px; }
.benefit-subtitle { color: var(--muted); font-size: 16px; margin-top: 8px; }

.seo-section {
  background: var(--bg-3);
  padding: 88px 0;
}
.seo-section.alt { background: var(--bg); }
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}
.section-kicker {
  color: #c46a60;
  font-size: 13px;
  letter-spacing: .12em;
  margin-bottom: 12px;
}
.seo-section h2,
.page-hero h1,
.content-block h2 {
  color: #fff;
  font-size: clamp(28px, 4vw, 40px);
  line-height: 1.2;
  font-weight: 700;
}
.lead, .seo-section p, .content-block p, .content-block li {
  color: #b7b7b7;
  font-size: 16px;
  line-height: 1.8;
}
.lead { max-width: 760px; margin: 16px 0 0; }
.split {
  display: grid;
  grid-template-columns: 1.1fr .9fr;
  gap: 48px;
  align-items: start;
}
.feature-grid, .platform-grid, .guide-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin-top: 36px;
}
.card {
  background: var(--bg-2);
  border: 1px solid #333;
  padding: 28px 24px;
  min-height: 180px;
}
.card h3 {
  color: #fff;
  font-size: 20px;
  margin: 12px 0 10px;
}
.card p, .card li { color: #a9a9a9; font-size: 15px; line-height: 1.7; }
.card a { color: #ff8b80; }
.card a:hover { color: #fff; }
.card-num { color: var(--red); font-size: 13px; letter-spacing: .08em; }

.page-hero {
  background: linear-gradient(180deg, #1a1a1a 0%, var(--bg) 100%);
  padding: 48px 0 36px;
  border-bottom: 1px solid #2a2a2a;
}
.breadcrumb { color: #8d8d8d; font-size: 14px; margin-bottom: 16px; }
.breadcrumb a { color: #cfcfcf; }
.page-hero p { color: #a3a3a3; margin-top: 12px; max-width: 720px; }

.page-main { padding: 56px 0 80px; }
.content-block { max-width: 860px; }
.content-block + .content-block { margin-top: 42px; }
.content-block h2 { font-size: 28px; margin-bottom: 14px; }
.content-block h3 { color: #fff; font-size: 20px; margin: 22px 0 10px; }
.content-block ul, .content-block ol { padding-left: 20px; }
.content-block li { margin: 8px 0; }
.content-block ul { list-style: disc; }
.content-block a { color: #ff8b80; }

.download-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin: 28px 0 48px;
}
.download-card {
  background: var(--bg-2);
  border: 1px solid #333;
  padding: 32px 24px;
  text-align: center;
}
.download-card h3 { color: #fff; font-size: 22px; margin: 10px 0; }
.download-card p { color: #a3a3a3; margin-bottom: 20px; }
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 20px;
  border-radius: 6px;
  border: 0;
  cursor: pointer;
  font-size: 15px;
}
.btn-primary { background: var(--red); color: #fff; }
.btn-primary:hover { background: var(--red-hover); }
.btn-lg { min-width: 180px; }
.cta-band {
  background: var(--red-band);
  text-align: center;
  padding: 56px 0;
}
.cta-band h2 { color: #fff; margin-bottom: 10px; }
.cta-band p { color: #e7c4bf; margin-bottom: 22px; }

.faq-list { max-width: 860px; }
.faq-list h2 { color: #fff; font-size: 22px; margin: 28px 0 12px; }
.faq-item {
  border-bottom: 1px solid #333;
  padding: 6px 0;
}
.faq-item summary {
  cursor: pointer;
  color: #fff;
  font-size: 17px;
  min-height: 52px;
  display: flex;
  align-items: center;
  list-style: none;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+";
  margin-left: auto;
  color: #888;
  font-size: 22px;
}
.faq-item[open] summary::after { content: "–"; }
.faq-item p { color: #b0b0b0; padding: 0 0 16px; }

.contact-form, .company-facts {
  max-width: 640px;
  margin-top: 28px;
}
.form-group { margin-bottom: 16px; }
.form-group label { display: block; color: #fff; margin-bottom: 8px; }
.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  background: #111;
  border: 1px solid #3a3a3a;
  color: #fff;
  padding: 12px 14px;
  border-radius: 4px;
}
.form-group textarea { min-height: 140px; resize: vertical; }
.form-note { color: #9ad89a; margin-top: 12px; min-height: 24px; }
.company-facts div {
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: 12px;
  padding: 12px 0;
  border-bottom: 1px solid #333;
}
.company-facts dt { color: #8d8d8d; }
.company-facts dd { color: #fff; }

.site-footer {
  background: #101010;
  border-top: 1px solid #2a2a2a;
  padding: 48px 0 24px;
  color: #8a8a8a;
  font-size: 14px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr repeat(3, 1fr);
  gap: 28px;
}
.footer-brand p { margin-top: 12px; max-width: 280px; line-height: 1.7; }
.footer-links h2, .footer-links h4 {
  color: #fff;
  font-size: 15px;
  margin-bottom: 12px;
  font-weight: 700;
}
.footer-links a {
  display: block;
  min-height: 32px;
  color: #9a9a9a;
}
.footer-links a:hover { color: #fff; }
.footer-bottom {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 36px;
  padding-top: 18px;
  border-top: 1px solid #2a2a2a;
  color: #666;
  font-size: 13px;
}
.footer-bottom a { color: #888; }

@media (max-width: 1100px) {
  .hero-layout { grid-template-columns: 1fr; min-height: 0; padding-bottom: 0; }
  .hero-band { top: 48%; height: 140px; }
  .hero-copy { text-align: left; max-width: 520px; }
  .hero-visual { justify-content: center; margin-top: 24px; }
  .split, .feature-grid, .platform-grid, .guide-grid, .download-cards, .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
  .benefit { background: var(--bg-3); }
}

@media (max-width: 820px) {
  .nav-toggle { display: flex; }
  .header-cta { display: none; }
  .main-nav {
    display: none;
    position: absolute;
    left: 0;
    right: 0;
    top: var(--header-h);
    background: #1b1b1b;
    border-bottom: 1px solid #333;
    padding: 12px 24px 20px;
  }
  .header-inner.open .main-nav { display: block; }
  .main-nav ul { flex-direction: column; align-items: flex-start; }
  .qr-block { display: none; }
  .hero h1 { font-size: 36px; }
  .hero-sub { font-size: 22px; }
  .download-btn { margin: 0 auto; }
  .hero-copy { text-align: center; }
  .download-tip { margin-bottom: 8px; }
  .hero-visual { padding-top: 36px; }
  .benefit-list, .feature-grid, .platform-grid, .guide-grid, .download-cards, .split, .footer-grid {
    grid-template-columns: 1fr;
  }
  .benefit-item { margin-bottom: 28px; }
  .footer-bottom { justify-content: center; text-align: center; }
}

@media (max-width: 480px) {
  .hero h1 { font-size: 32px; }
  .download-btn { width: 70%; }
  .container { padding: 0 18px; }
  .seo-section, .page-main { padding: 48px 0; }
}