:root {
  --ink: #191724;
  --ink-soft: #45414e;
  --paper: #fffaf2;
  --paper-deep: #f2eee6;
  --white: #ffffff;
  --coral: #fa5a4a;
  --coral-dark: #cf382d;
  --mint: #35d0ba;
  --yellow: #f4c95d;
  --line: #d8d1c8;
  --shadow: 6px 6px 0 var(--ink);
  --max-width: 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.menu-open {
  overflow: hidden;
}

img {
  max-width: 100%;
  height: auto;
}

a {
  color: inherit;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

:focus-visible {
  outline: 3px solid var(--mint);
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 1000;
  padding: 8px 14px;
  color: var(--white);
  background: var(--ink);
  transform: translateY(-160%);
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 2px solid var(--ink);
  background: rgba(255, 250, 242, 0.96);
  backdrop-filter: blur(12px);
}

.nav-shell {
  display: flex;
  width: min(calc(100% - 40px), var(--max-width));
  min-height: 72px;
  margin: 0 auto;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  font-size: 22px;
  font-weight: 900;
  text-decoration: none;
}

.brand img {
  width: 42px;
  height: 42px;
  border: 2px solid var(--ink);
  border-radius: 10px;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.site-nav a {
  position: relative;
  font-size: 15px;
  font-weight: 700;
  text-decoration: none;
}

.site-nav a:not(.download-button)::after {
  position: absolute;
  right: 0;
  bottom: -6px;
  left: 0;
  height: 3px;
  background: var(--coral);
  content: "";
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 180ms ease;
}

.site-nav a:hover::after,
.site-nav a[aria-current="page"]::after {
  transform: scaleX(1);
}

.download-button {
  display: inline-flex;
  min-height: 46px;
  padding: 10px 20px;
  align-items: center;
  justify-content: center;
  gap: 10px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  color: var(--white);
  background: var(--coral);
  box-shadow: 4px 4px 0 var(--ink);
  font-weight: 900;
  letter-spacing: 0;
  text-decoration: none;
  transition: transform 150ms ease, box-shadow 150ms ease, background 150ms ease;
}

.download-button::before {
  width: 9px;
  height: 9px;
  border-right: 3px solid currentColor;
  border-bottom: 3px solid currentColor;
  content: "";
  transform: translateY(-2px) rotate(45deg);
}

.download-button:hover {
  background: var(--coral-dark);
  box-shadow: 2px 2px 0 var(--ink);
  transform: translate(2px, 2px);
}

.download-button.large {
  min-width: 176px;
  min-height: 54px;
  padding: 12px 24px;
  font-size: 17px;
}

.download-button.light {
  color: var(--ink);
  background: var(--white);
}

.download-button.light:hover {
  background: var(--yellow);
}

.menu-toggle {
  display: none;
  width: 44px;
  height: 44px;
  padding: 10px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--white);
  cursor: pointer;
}

.menu-toggle span {
  display: block;
  height: 2px;
  margin: 5px 0;
  background: var(--ink);
}

.shell {
  width: min(calc(100% - 40px), var(--max-width));
  margin: 0 auto;
}

.hero {
  position: relative;
  overflow: hidden;
  border-bottom: 2px solid var(--ink);
}

.hero::before,
.cta-band::before {
  position: absolute;
  inset: 0;
  opacity: 0.17;
  background-image: radial-gradient(var(--ink) 1.3px, transparent 1.3px);
  background-size: 14px 14px;
  content: "";
  pointer-events: none;
}

.hero-grid {
  position: relative;
  display: grid;
  min-height: 650px;
  padding: 76px 0 66px;
  grid-template-columns: 1.03fr 0.97fr;
  align-items: center;
  gap: 72px;
}

.eyebrow {
  display: inline-flex;
  margin: 0 0 18px;
  padding: 5px 11px;
  border: 2px solid var(--ink);
  border-radius: 4px;
  background: var(--yellow);
  font-size: 13px;
  font-weight: 900;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1,
h2,
h3 {
  line-height: 1.18;
  letter-spacing: 0;
}

h1 {
  max-width: 650px;
  margin-bottom: 24px;
  font-size: clamp(44px, 6vw, 76px);
  font-weight: 950;
}

.hero-copy {
  max-width: 620px;
  margin-bottom: 28px;
  color: var(--ink-soft);
  font-size: 18px;
}

.hero-actions {
  display: flex;
  margin-bottom: 28px;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}

.text-link {
  font-weight: 800;
  text-underline-offset: 5px;
  text-decoration-thickness: 2px;
}

.hero-facts {
  display: flex;
  margin: 0;
  padding: 0;
  flex-wrap: wrap;
  gap: 10px;
  list-style: none;
}

.hero-facts li {
  padding: 7px 12px;
  border: 1px solid var(--ink);
  border-radius: 4px;
  background: var(--white);
  font-size: 13px;
  font-weight: 800;
}

.hero-visual {
  position: relative;
  min-height: 510px;
}

.phone-stack {
  position: absolute;
  inset: 0;
}

.phone {
  position: absolute;
  overflow: hidden;
  width: min(280px, 68%);
  border: 5px solid var(--ink);
  border-radius: 26px;
  background: var(--white);
  box-shadow: 10px 12px 0 var(--ink);
}

.phone img,
.preview-frame img {
  display: block;
  width: 100%;
  max-width: 400px;
  height: auto;
}

.phone.primary {
  top: 0;
  right: 4%;
  z-index: 2;
  transform: rotate(3deg);
}

.phone.secondary {
  bottom: 0;
  left: 2%;
  z-index: 1;
  width: min(235px, 57%);
  transform: rotate(-6deg);
}

.burst {
  position: absolute;
  right: -2%;
  bottom: 12%;
  z-index: 3;
  display: grid;
  width: 118px;
  height: 118px;
  padding: 15px;
  place-items: center;
  border: 3px solid var(--ink);
  border-radius: 50%;
  background: var(--mint);
  font-size: 14px;
  font-weight: 950;
  line-height: 1.3;
  text-align: center;
  transform: rotate(8deg);
}

.metric-strip {
  border-bottom: 2px solid var(--ink);
  background: var(--ink);
  color: var(--white);
}

.metrics {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
}

.metric {
  min-height: 120px;
  padding: 26px 30px;
  border-left: 1px solid #57525e;
}

.metric:last-child {
  border-right: 1px solid #57525e;
}

.metric strong,
.metric span {
  display: block;
}

.metric strong {
  margin-bottom: 2px;
  color: var(--yellow);
  font-size: 28px;
}

.metric span {
  color: #dcd7df;
  font-size: 14px;
}

.section {
  padding: 90px 0;
  border-bottom: 2px solid var(--ink);
}

.section-heading {
  display: flex;
  margin-bottom: 36px;
  align-items: end;
  justify-content: space-between;
  gap: 28px;
}

.section-heading h2 {
  max-width: 760px;
  margin: 0;
  font-size: clamp(32px, 4vw, 52px);
  font-weight: 950;
}

.section-index {
  color: var(--coral);
  font-size: 14px;
  font-weight: 950;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 18px;
}

.feature-card {
  min-height: 250px;
  padding: 28px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--white);
}

.feature-card:nth-child(1),
.feature-card:nth-child(4) {
  grid-column: span 7;
}

.feature-card:nth-child(2),
.feature-card:nth-child(3) {
  grid-column: span 5;
}

.feature-card.accent {
  background: var(--mint);
}

.feature-card.warm {
  background: var(--yellow);
}

.feature-number {
  display: block;
  margin-bottom: 34px;
  font-size: 13px;
  font-weight: 950;
}

.feature-card h3 {
  margin-bottom: 12px;
  font-size: 25px;
}

.feature-card p {
  margin-bottom: 0;
  color: #393641;
}

.showcase {
  background: var(--paper-deep);
}

.preview-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  align-items: start;
  gap: 18px;
}

.preview-item {
  margin: 0;
}

.preview-frame {
  overflow: hidden;
  border: 3px solid var(--ink);
  border-radius: 12px;
  background: var(--white);
  box-shadow: 5px 5px 0 var(--ink);
}

.preview-item:nth-child(even) {
  margin-top: 44px;
}

.preview-item figcaption {
  margin-top: 14px;
  font-size: 14px;
  font-weight: 800;
}

.routes {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.route-link {
  display: grid;
  min-height: 290px;
  padding: 34px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--white);
  box-shadow: var(--shadow);
  text-decoration: none;
  transition: transform 150ms ease, box-shadow 150ms ease;
}

.route-link:hover {
  box-shadow: 2px 2px 0 var(--ink);
  transform: translate(4px, 4px);
}

.route-link.coral {
  background: var(--coral);
  color: var(--white);
}

.route-label {
  font-size: 13px;
  font-weight: 900;
}

.route-link h3 {
  margin: auto 0 16px;
  font-size: 32px;
}

.route-link p {
  margin: 0;
}

.review-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.review {
  margin: 0;
  padding: 28px;
  border-top: 5px solid var(--coral);
  background: var(--white);
}

.review p {
  min-height: 112px;
  margin-bottom: 22px;
  font-size: 17px;
}

.review cite {
  font-size: 13px;
  font-style: normal;
  font-weight: 900;
}

.quick-faq {
  max-width: 900px;
  margin: 0 auto;
}

details {
  border-top: 2px solid var(--ink);
}

details:last-child {
  border-bottom: 2px solid var(--ink);
}

summary {
  position: relative;
  padding: 22px 56px 22px 0;
  cursor: pointer;
  font-size: 18px;
  font-weight: 900;
  list-style: none;
}

summary::-webkit-details-marker {
  display: none;
}

summary::after {
  position: absolute;
  top: 50%;
  right: 8px;
  width: 28px;
  height: 28px;
  border: 2px solid var(--ink);
  border-radius: 50%;
  content: "+";
  font-size: 22px;
  line-height: 23px;
  text-align: center;
  transform: translateY(-50%);
}

details[open] summary::after {
  content: "−";
}

details p,
details ol,
details ul {
  max-width: 800px;
  margin: 0 0 24px;
  color: var(--ink-soft);
}

.cta-band {
  position: relative;
  overflow: hidden;
  padding: 74px 0;
  color: var(--white);
  background: var(--coral);
}

.cta-inner {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 40px;
}

.cta-inner h2 {
  max-width: 720px;
  margin: 0;
  font-size: clamp(34px, 5vw, 58px);
}

.site-footer {
  padding: 48px 0 28px;
  color: #ebe8ed;
  background: var(--ink);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 50px;
}

.footer-brand {
  margin-bottom: 14px;
  color: var(--white);
}

.footer-note {
  max-width: 480px;
  color: #bdb8c1;
  font-size: 13px;
}

.footer-links h3 {
  margin-bottom: 14px;
  color: var(--yellow);
  font-size: 15px;
}

.footer-links a {
  display: block;
  margin-bottom: 9px;
  color: #ebe8ed;
  font-size: 14px;
  text-decoration: none;
}

.footer-links a:hover {
  color: var(--mint);
}

.footer-bottom {
  display: flex;
  margin-top: 40px;
  padding-top: 20px;
  border-top: 1px solid #4b4652;
  justify-content: space-between;
  gap: 24px;
  color: #aaa5ae;
  font-size: 12px;
}

.page-hero {
  position: relative;
  overflow: hidden;
  padding: 72px 0;
  border-bottom: 2px solid var(--ink);
  background: var(--mint);
}

.page-hero.coral {
  color: var(--white);
  background: var(--coral);
}

.page-hero .shell {
  position: relative;
}

.page-hero h1 {
  margin-bottom: 22px;
  font-size: clamp(40px, 6vw, 72px);
}

.page-hero p {
  max-width: 740px;
  margin-bottom: 0;
  font-size: 18px;
}

.breadcrumb {
  margin-bottom: 22px;
  font-size: 13px;
  font-weight: 800;
}

.breadcrumb a {
  text-underline-offset: 4px;
}

.content-layout {
  display: grid;
  padding: 72px 0 92px;
  grid-template-columns: minmax(0, 1fr) 280px;
  align-items: start;
  gap: 64px;
}

.article-content {
  min-width: 0;
}

.article-section {
  margin-bottom: 72px;
  scroll-margin-top: 100px;
}

.article-section:last-child {
  margin-bottom: 0;
}

.article-section h2 {
  margin-bottom: 26px;
  font-size: 34px;
  font-weight: 950;
}

.article-section h3 {
  margin: 30px 0 12px;
  font-size: 22px;
}

.article-section p {
  color: var(--ink-soft);
}

.step-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.step {
  display: grid;
  padding: 28px 0;
  border-top: 2px solid var(--ink);
  grid-template-columns: 76px minmax(0, 1fr);
  gap: 24px;
}

.step:last-child {
  border-bottom: 2px solid var(--ink);
}

.step-number {
  display: grid;
  width: 58px;
  height: 58px;
  place-items: center;
  border: 2px solid var(--ink);
  border-radius: 50%;
  background: var(--yellow);
  font-size: 18px;
  font-weight: 950;
}

.step h3 {
  margin: 0 0 10px;
}

.step p {
  margin-bottom: 0;
}

.note-box {
  margin: 28px 0;
  padding: 24px 26px;
  border: 2px solid var(--ink);
  border-left: 12px solid var(--coral);
  border-radius: 5px;
  background: var(--white);
}

.note-box strong {
  display: block;
  margin-bottom: 7px;
}

.note-box p {
  margin: 0;
}

.check-list {
  display: grid;
  margin: 0;
  padding: 0;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  list-style: none;
}

.check-list li {
  padding: 14px 16px 14px 44px;
  border: 1px solid var(--line);
  background: var(--white);
}

.check-list li::before {
  float: left;
  margin-left: -28px;
  color: var(--coral);
  content: "✓";
  font-weight: 950;
}

.article-aside {
  position: sticky;
  top: 100px;
  padding: 24px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--white);
  box-shadow: 5px 5px 0 var(--ink);
}

.article-aside h2 {
  margin-bottom: 14px;
  font-size: 18px;
}

.article-aside a:not(.download-button) {
  display: block;
  padding: 9px 0;
  border-bottom: 1px solid var(--line);
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
}

.article-aside .download-button {
  width: 100%;
  margin-top: 20px;
}

.feature-detail {
  display: grid;
  margin-bottom: 20px;
  padding: 28px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--white);
  grid-template-columns: 58px minmax(0, 1fr);
  gap: 22px;
}

.feature-detail .symbol {
  display: grid;
  width: 52px;
  height: 52px;
  place-items: center;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--mint);
  font-weight: 950;
}

.feature-detail:nth-child(even) .symbol {
  background: var(--yellow);
}

.feature-detail h3 {
  margin: 0 0 10px;
}

.feature-detail p {
  margin-bottom: 0;
}

.faq-group {
  margin-bottom: 54px;
}

.faq-group h2 {
  margin-bottom: 18px;
}

.related-links {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}

.related-links a {
  min-height: 130px;
  padding: 24px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--yellow);
  font-size: 20px;
  font-weight: 900;
  text-decoration: none;
}

.reveal {
  opacity: 1;
  transform: none;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

@media (max-width: 960px) {
  .hero-grid {
    min-height: auto;
    grid-template-columns: 1fr;
    gap: 50px;
  }

  .hero-visual {
    width: min(100%, 560px);
    min-height: 540px;
    margin: 0 auto;
  }

  .preview-grid {
    overflow-x: auto;
    padding: 0 8px 22px;
    grid-template-columns: repeat(5, 210px);
  }

  .content-layout {
    grid-template-columns: 1fr;
  }

  .article-aside {
    position: static;
    order: -1;
  }
}

@media (max-width: 760px) {
  .nav-shell,
  .shell {
    width: min(calc(100% - 28px), var(--max-width));
  }

  .menu-toggle {
    display: block;
  }

  .site-nav {
    position: fixed;
    top: 71px;
    right: 0;
    bottom: 0;
    left: 0;
    display: none;
    padding: 30px 22px;
    align-items: stretch;
    flex-direction: column;
    gap: 6px;
    background: var(--paper);
  }

  .site-nav.open {
    display: flex;
  }

  .site-nav a:not(.download-button) {
    padding: 14px 4px;
    border-bottom: 1px solid var(--line);
    font-size: 18px;
  }

  h1 {
    font-size: 46px;
  }

  .hero-grid {
    padding-top: 52px;
  }

  .metrics {
    grid-template-columns: 1fr 1fr;
  }

  .metric:nth-child(odd) {
    border-left: 0;
  }

  .feature-card:nth-child(n) {
    grid-column: 1 / -1;
  }

  .routes,
  .review-grid,
  .footer-grid,
  .related-links {
    grid-template-columns: 1fr;
  }

  .section {
    padding: 66px 0;
  }

  .section-heading,
  .cta-inner,
  .footer-bottom {
    align-items: flex-start;
    flex-direction: column;
  }

  .cta-inner {
    display: flex;
  }

  .check-list {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  body {
    font-size: 15px;
  }

  .brand img {
    width: 38px;
    height: 38px;
  }

  .hero-copy,
  .page-hero p {
    font-size: 16px;
  }

  .hero-visual {
    min-height: 430px;
  }

  .phone {
    width: 63%;
  }

  .phone.secondary {
    width: 54%;
  }

  .burst {
    width: 92px;
    height: 92px;
    font-size: 12px;
  }

  .metrics {
    grid-template-columns: 1fr;
  }

  .metric {
    min-height: 96px;
    border-right: 0;
    border-left: 0;
    border-bottom: 1px solid #57525e;
  }

  .step,
  .feature-detail {
    grid-template-columns: 1fr;
  }

  .route-link {
    min-height: 250px;
  }
}