:root {
  --ink: #15212b;
  --paper: #fffdf8;
  --surface: #ffffff;
  --teal: #0b9b8b;
  --teal-dark: #08776c;
  --coral: #ff625c;
  --yellow: #f4c84a;
  --muted: #5d6871;
  --line: #15212b;
  --shadow: 6px 6px 0 #15212b;
  --max: 1180px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.75;
}
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: .22;
  background-image: radial-gradient(#15212b 0.7px, transparent 0.7px);
  background-size: 16px 16px;
  mask-image: linear-gradient(to bottom, #000, transparent 34%);
  z-index: -1;
}
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; height: auto; }
button, a { -webkit-tap-highlight-color: transparent; }
.container { width: min(var(--max), calc(100% - 40px)); margin-inline: auto; }
.skip-link { position: absolute; left: -9999px; top: 8px; }
.skip-link:focus { left: 12px; z-index: 100; background: #fff; padding: 8px 12px; border: 2px solid var(--ink); }

.site-header {
  position: sticky;
  top: 0;
  z-index: 30;
  background: rgba(255,253,248,.96);
  border-bottom: 3px solid var(--ink);
  backdrop-filter: blur(10px);
}
.nav-wrap { min-height: 76px; display: flex; align-items: center; gap: 28px; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-size: 21px; font-weight: 900; white-space: nowrap; }
.brand img { width: 42px; height: 42px; border: 2px solid var(--ink); border-radius: 8px; }
.nav { margin-left: auto; display: flex; align-items: center; gap: 6px; }
.nav a { padding: 8px 12px; font-weight: 700; border-bottom: 3px solid transparent; }
.nav a:hover, .nav a[aria-current="page"] { border-color: var(--coral); }
.nav-toggle { display: none; margin-left: auto; width: 44px; height: 44px; border: 2px solid var(--ink); background: #fff; font-size: 24px; cursor: pointer; }
.download-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  min-height: 48px;
  padding: 10px 20px;
  background: var(--coral);
  color: #111;
  border: 3px solid var(--ink);
  border-radius: 6px;
  box-shadow: 4px 4px 0 var(--ink);
  font-weight: 900;
  white-space: nowrap;
  transition: transform .16s ease, box-shadow .16s ease;
}
.download-btn:hover { transform: translate(3px,3px); box-shadow: 1px 1px 0 var(--ink); }
.download-btn--small { min-height: 42px; padding: 6px 14px; }

.hero { padding: 72px 0 64px; overflow: hidden; }
.hero-grid { display: grid; grid-template-columns: minmax(0,1.05fr) minmax(360px,.95fr); align-items: center; gap: 64px; }
.eyebrow { display: inline-block; margin-bottom: 18px; padding: 4px 10px; background: var(--yellow); border: 2px solid var(--ink); font-weight: 900; }
h1, h2, h3, p { margin-top: 0; }
h1, h2, h3 { line-height: 1.22; letter-spacing: 0; }
h1 { margin-bottom: 22px; font-size: clamp(42px, 7vw, 78px); font-weight: 950; }
h2 { margin-bottom: 28px; font-size: clamp(28px, 4vw, 44px); font-weight: 950; }
h3 { margin-bottom: 10px; font-size: 21px; font-weight: 900; }
.hero-copy > p { max-width: 650px; font-size: 18px; color: #3f4b54; }
.hero-actions { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; margin-top: 28px; }
.text-link { font-weight: 900; border-bottom: 3px solid var(--teal); }
.quick-facts { display: flex; flex-wrap: wrap; gap: 10px; margin: 28px 0 0; padding: 0; list-style: none; }
.quick-facts li { padding: 5px 10px; background: #fff; border: 2px solid var(--ink); font-weight: 700; }
.phone-stage { position: relative; min-height: 590px; }
.phone-stage::before { content: ""; position: absolute; width: 310px; height: 450px; right: 18px; top: 70px; background: var(--yellow); border: 3px solid var(--ink); transform: rotate(5deg); }
.phone {
  position: absolute;
  width: min(285px, 72vw);
  padding: 10px;
  background: #101820;
  border: 3px solid var(--ink);
  border-radius: 24px;
  box-shadow: var(--shadow);
}
.phone img { width: 100%; max-width: 400px; border-radius: 14px; }
.phone--front { top: 0; left: 12px; z-index: 2; transform: rotate(-3deg); }
.phone--back { right: 0; bottom: 0; width: 235px; transform: rotate(4deg); }
.burst { position: absolute; right: 2px; top: 12px; z-index: 3; width: 112px; height: 112px; display: grid; place-items: center; text-align: center; background: var(--coral); border: 3px solid var(--ink); border-radius: 50%; font-weight: 950; transform: rotate(9deg); }

.band { padding: 74px 0; border-top: 3px solid var(--ink); }
.band--teal { background: var(--teal); color: #081a19; }
.band--dark { background: var(--ink); color: #fff; }
.section-kicker { margin-bottom: 8px; font-size: 13px; font-weight: 950; text-transform: uppercase; }
.feature-grid { display: grid; grid-template-columns: repeat(4,1fr); gap: 18px; }
.feature-card { min-height: 220px; padding: 24px; background: #fff; border: 3px solid var(--ink); border-radius: 6px; box-shadow: 5px 5px 0 var(--ink); }
.feature-card:nth-child(2) { background: #fff4d0; }
.feature-card:nth-child(3) { background: #ffe2df; }
.feature-card:nth-child(4) { background: #e1f6f2; }
.feature-number { display: block; margin-bottom: 28px; font-size: 14px; font-weight: 950; }
.feature-card p { margin-bottom: 0; color: #45515a; }

.preview-layout { display: grid; grid-template-columns: .7fr 1.3fr; gap: 48px; align-items: start; }
.preview-copy { position: sticky; top: 120px; }
.preview-copy ul { margin: 0; padding-left: 20px; }
.screenshot-grid { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 18px; align-items: start; }
.shot { margin: 0; padding: 10px; background: #fff; border: 3px solid var(--ink); border-radius: 6px; box-shadow: 5px 5px 0 var(--ink); }
.shot:nth-child(even) { margin-top: 56px; }
.shot img { width: 100%; max-width: 400px; margin-inline: auto; }
.shot figcaption { padding: 12px 6px 4px; font-weight: 800; }

.route-grid { display: grid; grid-template-columns: repeat(2,1fr); border: 3px solid var(--ink); }
.route-card { min-height: 300px; padding: 34px; background: #fff; }
.route-card + .route-card { border-left: 3px solid var(--ink); background: var(--yellow); }
.route-tag { display: inline-block; margin-bottom: 42px; padding: 3px 9px; border: 2px solid var(--ink); background: var(--teal); font-weight: 900; }
.route-card p { color: #44505a; }
.route-link { display: inline-block; margin-top: 18px; font-weight: 950; border-bottom: 4px solid var(--coral); }

.review-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 18px; }
blockquote { margin: 0; }
.quote { padding: 26px; color: var(--ink); background: #fff; border: 3px solid var(--ink); border-radius: 6px; }
.quote p { font-size: 17px; font-weight: 700; }
.quote footer { font-weight: 900; color: var(--teal-dark); }
.stat-strip { display: grid; grid-template-columns: repeat(3,1fr); margin-top: 24px; border: 3px solid var(--ink); background: var(--yellow); color: var(--ink); }
.stat { padding: 18px; text-align: center; }
.stat + .stat { border-left: 3px solid var(--ink); }
.stat strong { display: block; font-size: 26px; }

.mini-faq { display: grid; grid-template-columns: repeat(2,1fr); gap: 14px 34px; }
.mini-faq article { border-top: 3px solid var(--ink); padding-top: 18px; }
.mini-faq p { color: #53606a; }

.download-band { padding: 54px 0; background: var(--coral); border-top: 3px solid var(--ink); border-bottom: 3px solid var(--ink); }
.download-row { display: flex; align-items: center; justify-content: space-between; gap: 26px; }
.download-row h2 { margin: 0; max-width: 720px; }
.download-row .download-btn { background: #fff; }

.page-hero { padding: 62px 0 46px; border-bottom: 3px solid var(--ink); }
.page-hero--yellow { background: var(--yellow); }
.page-hero--teal { background: #d9f2ed; }
.page-hero h1 { max-width: 1060px; font-size: clamp(38px,5vw,58px); }
.page-hero p { max-width: 760px; margin-bottom: 0; font-size: 18px; }
.breadcrumb { margin-bottom: 20px; font-size: 14px; font-weight: 800; }
.article-shell { display: grid; grid-template-columns: 250px minmax(0,1fr); gap: 54px; padding: 58px 0 80px; }
.toc { position: sticky; top: 104px; align-self: start; padding: 20px; border: 3px solid var(--ink); background: #fff; }
.toc strong { display: block; margin-bottom: 10px; }
.toc a { display: block; padding: 6px 0; border-bottom: 1px solid #ccd2d5; font-weight: 700; }
.article h2 { margin-top: 54px; padding-top: 8px; border-top: 4px solid var(--ink); font-size: 32px; }
.article h2:first-child { margin-top: 0; }
.article h3 { margin-top: 28px; }
.step-list { counter-reset: step; list-style: none; padding: 0; margin: 0; }
.step { counter-increment: step; display: grid; grid-template-columns: 76px 1fr; gap: 20px; margin-bottom: 22px; padding: 24px; border: 3px solid var(--ink); background: #fff; }
.step::before { content: counter(step, decimal-leading-zero); display: grid; place-items: center; width: 62px; height: 62px; background: var(--teal); border: 3px solid var(--ink); font-size: 22px; font-weight: 950; }
.step p:last-child { margin-bottom: 0; }
.notice { margin: 26px 0; padding: 20px 22px; background: #fff4d0; border-left: 8px solid var(--yellow); border-top: 2px solid var(--ink); border-right: 2px solid var(--ink); border-bottom: 2px solid var(--ink); }
.checklist { display: grid; grid-template-columns: repeat(2,1fr); gap: 12px; padding: 0; list-style: none; }
.checklist li { padding: 14px 16px 14px 44px; position: relative; background: #fff; border: 2px solid var(--ink); }
.checklist li::before { content: "✓"; position: absolute; left: 14px; color: var(--teal-dark); font-weight: 950; }
.article-shot { max-width: 340px; margin: 24px auto; padding: 8px; border: 3px solid var(--ink); background: #fff; box-shadow: var(--shadow); }
.article-shot img { max-width: 400px; }
.article-shot figcaption { padding: 10px 4px 3px; font-size: 14px; font-weight: 800; }

.faq-stack { display: grid; gap: 14px; }
.faq-stack details { background: #fff; border: 3px solid var(--ink); }
.faq-stack summary { cursor: pointer; padding: 18px 52px 18px 20px; position: relative; font-size: 18px; font-weight: 900; list-style: none; }
.faq-stack summary::-webkit-details-marker { display: none; }
.faq-stack summary::after { content: "+"; position: absolute; right: 20px; top: 13px; font-size: 28px; }
.faq-stack details[open] summary { background: var(--yellow); border-bottom: 2px solid var(--ink); }
.faq-stack details[open] summary::after { content: "−"; }
.faq-answer { padding: 18px 20px 22px; }
.faq-answer p:last-child { margin-bottom: 0; }
.support-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 16px; }
.support-card { padding: 22px; border: 3px solid var(--ink); background: #fff; }

.site-footer { padding: 46px 0 28px; background: var(--ink); color: #fff; }
.footer-grid { display: grid; grid-template-columns: 1fr auto; gap: 36px; align-items: start; }
.footer-brand { color: #fff; }
.footer-brand img { background: #fff; }
.footer-links { display: flex; flex-wrap: wrap; gap: 18px; font-weight: 800; }
.disclaimer { margin: 28px 0 0; padding-top: 20px; border-top: 1px solid #63707a; color: #d6dce0; font-size: 13px; }
.copyright { margin: 8px 0 0; color: #aeb8bf; font-size: 13px; }

@media (max-width: 920px) {
  .nav-toggle { display: block; }
  .nav { display: none; position: absolute; left: 0; right: 0; top: 76px; padding: 14px 20px 20px; background: var(--paper); border-bottom: 3px solid var(--ink); flex-direction: column; align-items: stretch; }
  .nav.is-open { display: flex; }
  .nav .download-btn { margin-top: 6px; }
  .hero-grid, .preview-layout { grid-template-columns: 1fr; }
  .hero-copy { max-width: 760px; }
  .phone-stage { width: min(560px,100%); margin-inline: auto; }
  .feature-grid { grid-template-columns: repeat(2,1fr); }
  .preview-copy { position: static; }
  .article-shell { grid-template-columns: 1fr; }
  .toc { position: static; }
  .review-grid, .support-grid { grid-template-columns: 1fr; }
}

@media (max-width: 620px) {
  .container { width: min(100% - 24px,var(--max)); }
  .site-header .download-btn { width: 100%; }
  .hero { padding-top: 44px; }
  .hero-grid { gap: 38px; }
  h1 { font-size: 42px; }
  h2 { font-size: 30px; }
  .phone-stage { min-height: 520px; }
  .phone--front { left: 0; }
  .phone--back { right: 0; width: 190px; }
  .burst { width: 92px; height: 92px; font-size: 14px; }
  .feature-grid, .screenshot-grid, .route-grid, .mini-faq, .checklist { grid-template-columns: 1fr; }
  .shot:nth-child(even) { margin-top: 0; }
  .route-card + .route-card { border-left: 0; border-top: 3px solid var(--ink); }
  .stat-strip { grid-template-columns: 1fr; }
  .stat + .stat { border-left: 0; border-top: 3px solid var(--ink); }
  .download-row { align-items: stretch; flex-direction: column; }
  .step { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}