:root {
  --ink: #17151f;
  --paper: #f8f6f1;
  --white: #ffffff;
  --muted: #696572;
  --line: #d9d5cc;
  --orange: #ff5a36;
  --orange-dark: #df3f20;
  --mint: #2bd7a0;
  --yellow: #ffd65a;
  --violet: #6c56e8;
  --shadow: 5px 5px 0 var(--ink);
  --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;
  line-height: 1.75;
  letter-spacing: 0;
}

body.nav-open {
  overflow: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

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

button,
input {
  font: inherit;
}

.skip-link {
  position: fixed;
  left: 12px;
  top: -60px;
  z-index: 100;
  padding: 10px 16px;
  color: var(--white);
  background: var(--ink);
}

.skip-link:focus {
  top: 12px;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 2px solid var(--ink);
  background: rgba(248, 246, 241, 0.96);
  backdrop-filter: blur(10px);
}

.nav-wrap {
  min-height: 72px;
  display: flex;
  align-items: center;
  gap: 34px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
  font-size: 22px;
  font-weight: 900;
}

.brand img {
  width: 42px;
  height: 42px;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 26px;
  margin-left: auto;
  font-size: 15px;
  font-weight: 700;
}

.main-nav a:not(.download-btn) {
  position: relative;
  padding: 24px 0 20px;
}

.main-nav a:not(.download-btn)::after {
  content: "";
  position: absolute;
  left: 0;
  right: 100%;
  bottom: 15px;
  height: 3px;
  background: var(--orange);
  transition: right 160ms ease;
}

.main-nav a:hover::after,
.main-nav a[aria-current="page"]::after {
  right: 0;
}

.download-btn {
  min-height: 46px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border: 2px solid var(--ink);
  border-radius: 4px;
  color: var(--white);
  background: var(--orange);
  box-shadow: 3px 3px 0 var(--ink);
  font-weight: 900;
  transition: transform 140ms ease, box-shadow 140ms ease, background 140ms ease;
}

.download-btn::before {
  content: "↓";
  font-size: 19px;
  line-height: 1;
}

.download-btn:hover {
  transform: translate(2px, 2px);
  box-shadow: 1px 1px 0 var(--ink);
  background: var(--orange-dark);
}

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

.menu-btn {
  display: none;
  width: 44px;
  height: 44px;
  margin-left: auto;
  border: 2px solid var(--ink);
  border-radius: 4px;
  background: var(--white);
  cursor: pointer;
}

.menu-btn span,
.menu-btn::before,
.menu-btn::after {
  content: "";
  display: block;
  width: 21px;
  height: 2px;
  margin: 5px auto;
  background: var(--ink);
  transition: transform 160ms ease, opacity 160ms ease;
}

.hero {
  position: relative;
  overflow: hidden;
  border-bottom: 2px solid var(--ink);
  background-color: var(--yellow);
  background-image: radial-gradient(var(--ink) 0.8px, transparent 0.8px);
  background-size: 13px 13px;
}

.hero::after {
  content: "PLAY / READ / TALK";
  position: absolute;
  right: -12px;
  bottom: -21px;
  color: rgba(23, 21, 31, 0.09);
  font: 900 86px/1 Arial, sans-serif;
  white-space: nowrap;
  letter-spacing: 0;
}

.hero-grid {
  position: relative;
  z-index: 1;
  min-height: 630px;
  display: grid;
  grid-template-columns: 1.04fr 0.96fr;
  align-items: center;
  gap: 70px;
  padding-block: 74px 82px;
}

.eyebrow {
  display: inline-block;
  margin: 0 0 18px;
  padding: 5px 11px;
  border: 2px solid var(--ink);
  border-radius: 3px;
  background: var(--mint);
  box-shadow: 3px 3px 0 var(--ink);
  font-size: 13px;
  font-weight: 900;
}

.hero h1 {
  max-width: 640px;
  margin: 0;
  font-size: clamp(48px, 7vw, 86px);
  line-height: 1.03;
  font-weight: 900;
  letter-spacing: 0;
}

.hero-lead {
  max-width: 620px;
  margin: 24px 0 28px;
  font-size: 19px;
  font-weight: 650;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 15px;
}

.text-link {
  border-bottom: 2px solid var(--ink);
  font-weight: 800;
}

.hero-notes {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
  font-size: 14px;
  font-weight: 800;
}

.hero-notes li::before {
  content: "✓";
  margin-right: 6px;
  color: var(--orange-dark);
}

.phone-stage {
  position: relative;
  min-height: 470px;
  display: grid;
  place-items: center;
}

.phone-stage::before,
.phone-stage::after {
  content: "";
  position: absolute;
  border: 2px solid var(--ink);
}

.phone-stage::before {
  width: 330px;
  height: 330px;
  border-radius: 50%;
  background: var(--orange);
}

.phone-stage::after {
  width: 365px;
  height: 140px;
  transform: rotate(-9deg);
  background: var(--violet);
  box-shadow: var(--shadow);
}

.hero-phone {
  position: relative;
  z-index: 2;
  width: min(100%, 272px);
  transform: rotate(3deg);
  border: 3px solid var(--ink);
  border-radius: 28px;
  box-shadow: 12px 13px 0 var(--ink);
}

.sticker {
  position: absolute;
  z-index: 3;
  display: grid;
  place-items: center;
  width: 94px;
  height: 94px;
  border: 2px solid var(--ink);
  border-radius: 50%;
  background: var(--mint);
  box-shadow: 4px 4px 0 var(--ink);
  font-size: 15px;
  font-weight: 900;
  text-align: center;
  transform: rotate(-8deg);
}

.sticker.top {
  right: 2%;
  top: 10%;
}

.ticker {
  overflow: hidden;
  border-bottom: 2px solid var(--ink);
  background: var(--ink);
  color: var(--white);
}

.ticker-track {
  width: 200%;
  display: grid;
  grid-template-columns: repeat(10, minmax(0, 1fr));
  align-items: center;
  padding: 13px 0;
  animation: ticker 24s linear infinite;
  font-size: 13px;
  font-weight: 900;
}

.ticker-track span {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 0;
  white-space: nowrap;
  text-align: center;
}

.ticker-track span::before {
  content: "✦";
  margin-right: clamp(7px, 1.4vw, 20px);
  color: var(--mint);
}

@keyframes ticker {
  to { transform: translateX(-50%); }
}

.section {
  padding-block: 88px;
}

.section.alt {
  border-block: 2px solid var(--ink);
  background: var(--white);
}

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

.section h2,
.content-page h2 {
  margin: 0;
  font-size: clamp(30px, 4.4vw, 50px);
  line-height: 1.15;
  font-weight: 900;
}

.section-index {
  color: var(--orange);
  font: 900 18px/1 Arial, sans-serif;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 20px;
}

.feature-card {
  min-height: 220px;
  grid-column: span 4;
  padding: 25px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--white);
  box-shadow: var(--shadow);
}

.feature-card:nth-child(2) {
  background: var(--mint);
}

.feature-card:nth-child(4) {
  grid-column: span 7;
  background: var(--yellow);
}

.feature-card:nth-child(5) {
  grid-column: span 5;
  background: #ddd7ff;
}

.feature-num {
  display: block;
  margin-bottom: 24px;
  color: var(--orange-dark);
  font: 900 15px/1 Arial, sans-serif;
}

.feature-card h3 {
  margin: 0 0 8px;
  font-size: 23px;
  line-height: 1.2;
}

.feature-card p {
  margin: 0;
  color: #35313c;
}

.showcase-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  align-items: start;
  gap: 34px;
}

.screen-card {
  margin: 0;
}

.screen-card:nth-child(2) {
  margin-top: 46px;
}

.screen-card img {
  width: 100%;
  max-width: 400px;
  height: auto;
  margin-inline: auto;
  border: 2px solid var(--ink);
  border-radius: 24px;
  box-shadow: 8px 8px 0 var(--ink);
}

.screen-card figcaption {
  max-width: 400px;
  margin: 20px auto 0;
  font-weight: 750;
}

.screen-card figcaption strong {
  display: block;
  font-size: 19px;
}

.screen-card figcaption span {
  display: block;
  color: var(--muted);
  font-size: 13px;
}

.route-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 22px;
}

.route-card {
  position: relative;
  min-height: 320px;
  overflow: hidden;
  padding: 36px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  color: var(--white);
  background: var(--ink);
}

.route-card.faq-route {
  color: var(--ink);
  background: var(--orange);
}

.route-tag {
  display: inline-block;
  padding: 4px 9px;
  border: 1px solid currentColor;
  border-radius: 3px;
  font-size: 12px;
  font-weight: 900;
}

.route-card h3 {
  max-width: 520px;
  margin: 60px 0 14px;
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1.1;
}

.route-card p {
  max-width: 540px;
  margin: 0 0 24px;
}

.route-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border-bottom: 2px solid currentColor;
  font-weight: 900;
}

.route-link::after {
  content: "→";
  font-size: 20px;
}

.proof-strip {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border: 2px solid var(--ink);
  background: var(--white);
  box-shadow: var(--shadow);
}

.proof-item {
  padding: 28px;
  border-right: 2px solid var(--ink);
}

.proof-item:last-child {
  border-right: 0;
}

.proof-item strong {
  display: block;
  color: var(--orange-dark);
  font-size: 30px;
  line-height: 1.2;
}

.proof-item span {
  color: var(--muted);
  font-size: 14px;
}

.review-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 30px;
}

.review-card {
  margin: 0;
  padding: 25px;
  border-left: 5px solid var(--orange);
  background: var(--white);
}

.review-card p {
  margin: 0 0 18px;
  font-size: 16px;
  font-weight: 700;
}

.review-card cite {
  color: var(--muted);
  font-size: 13px;
  font-style: normal;
}

.review-note {
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 12px;
}

.home-faq {
  display: grid;
  grid-template-columns: 0.72fr 1.28fr;
  gap: 60px;
}

.faq-list {
  border-top: 2px solid var(--ink);
}

.faq-item {
  border-bottom: 2px solid var(--ink);
}

.faq-question {
  width: 100%;
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 22px 4px;
  border: 0;
  color: var(--ink);
  background: transparent;
  text-align: left;
  font-weight: 900;
  cursor: pointer;
}

.faq-question::after {
  content: "+";
  width: 28px;
  flex: 0 0 28px;
  font-size: 26px;
  line-height: 1;
  text-align: center;
}

.faq-question[aria-expanded="true"]::after {
  content: "−";
}

.faq-answer {
  padding: 0 40px 22px 4px;
  color: #403b47;
}

.faq-answer p {
  margin: 0;
}

.final-cta {
  overflow: hidden;
  padding-block: 72px;
  border-block: 2px solid var(--ink);
  color: var(--white);
  background: var(--violet);
}

.cta-grid {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 30px;
}

.final-cta h2 {
  margin: 0 0 10px;
  font-size: clamp(34px, 5vw, 58px);
  line-height: 1.05;
}

.final-cta p {
  margin: 0;
  color: #f0edff;
}

.page-hero {
  position: relative;
  overflow: hidden;
  padding-block: 76px 66px;
  border-bottom: 2px solid var(--ink);
  background: var(--mint);
}

.page-hero.faq-page-hero {
  background: var(--orange);
}

.page-hero .container {
  position: relative;
  z-index: 1;
}

.page-hero h1 {
  max-width: 880px;
  margin: 12px 0 18px;
  font-size: clamp(40px, 6vw, 72px);
  line-height: 1.08;
  letter-spacing: 0;
}

.page-hero p {
  max-width: 780px;
  margin: 0;
  font-size: 18px;
  font-weight: 650;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 13px;
  font-weight: 800;
}

.breadcrumb span {
  color: var(--muted);
}

.content-layout {
  display: grid;
  grid-template-columns: 240px minmax(0, 1fr);
  align-items: start;
  gap: 58px;
  padding-block: 72px 96px;
}

.side-nav {
  position: sticky;
  top: 98px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--white);
  box-shadow: 4px 4px 0 var(--ink);
}

.side-nav strong {
  display: block;
  padding: 14px 17px;
  border-bottom: 2px solid var(--ink);
  background: var(--yellow);
}

.side-nav a {
  display: block;
  padding: 11px 17px;
  border-bottom: 1px solid var(--line);
  font-size: 14px;
  font-weight: 700;
}

.side-nav a:last-child {
  border-bottom: 0;
}

.side-nav a:hover {
  background: #f0ede5;
}

.article-section {
  scroll-margin-top: 96px;
  margin-bottom: 74px;
}

.article-section h2 {
  margin-bottom: 26px;
  font-size: clamp(28px, 4vw, 44px);
}

.article-section h3 {
  margin: 28px 0 8px;
  font-size: 22px;
}

.article-section p {
  margin: 0 0 17px;
}

.steps {
  display: grid;
  gap: 22px;
  counter-reset: step;
}

.step-card {
  position: relative;
  display: grid;
  grid-template-columns: 76px 1fr;
  gap: 24px;
  padding: 28px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--white);
  box-shadow: 4px 4px 0 var(--ink);
  counter-increment: step;
}

.step-card::before {
  content: counter(step, decimal-leading-zero);
  display: grid;
  place-items: center;
  width: 64px;
  height: 64px;
  border: 2px solid var(--ink);
  border-radius: 50%;
  background: var(--orange);
  font: 900 20px/1 Arial, sans-serif;
}

.step-card h3 {
  margin: 0 0 8px;
}

.step-card p {
  margin: 0;
}

.check-list,
.plain-list {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.check-list li,
.plain-list li {
  position: relative;
  padding-left: 26px;
}

.check-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--orange-dark);
  font-weight: 900;
}

.plain-list li::before {
  content: "■";
  position: absolute;
  left: 2px;
  top: 4px;
  color: var(--violet);
  font-size: 8px;
}

.notice {
  margin: 24px 0;
  padding: 18px 20px;
  border: 2px solid var(--ink);
  border-left-width: 8px;
  background: var(--yellow);
}

.notice strong {
  display: block;
  margin-bottom: 4px;
}

.inline-download {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  margin-top: 26px;
  padding: 22px;
  border: 2px solid var(--ink);
  background: #ddd7ff;
  box-shadow: 4px 4px 0 var(--ink);
}

.inline-download p {
  margin: 0;
  font-weight: 800;
}

.troubleshoot-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
}

.trouble-card {
  padding: 22px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--white);
}

.trouble-card h3 {
  margin: 0 0 8px;
}

.trouble-card p {
  margin: 0;
}

.faq-page-list .faq-item {
  border: 2px solid var(--ink);
  border-bottom: 0;
  background: var(--white);
}

.faq-page-list .faq-item:last-child {
  border-bottom: 2px solid var(--ink);
}

.faq-page-list .faq-question {
  padding-inline: 20px;
}

.faq-page-list .faq-answer {
  padding-inline: 20px 50px;
}

.topic-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 24px;
}

.topic-chips a {
  padding: 6px 12px;
  border: 2px solid var(--ink);
  border-radius: 3px;
  background: var(--white);
  font-size: 13px;
  font-weight: 800;
}

.topic-chips a:hover {
  background: var(--mint);
}

.related {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
}

.related a {
  min-height: 140px;
  padding: 22px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--white);
  box-shadow: 4px 4px 0 var(--ink);
}

.related strong {
  display: block;
  margin-bottom: 7px;
  font-size: 20px;
}

.related span {
  color: var(--muted);
}

.site-footer {
  padding-block: 58px 30px;
  color: #e9e6f0;
  background: var(--ink);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.3fr 0.7fr 0.7fr;
  gap: 50px;
}

.footer-brand {
  margin-bottom: 16px;
}

.site-footer h2 {
  margin: 0 0 12px;
  color: var(--white);
  font-size: 17px;
}

.site-footer p {
  margin: 0;
  color: #bcb6c8;
  font-size: 13px;
}

.footer-links {
  display: grid;
  gap: 7px;
  font-size: 14px;
}

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

.disclaimer {
  margin-top: 42px !important;
  padding-top: 24px;
  border-top: 1px solid #48434f;
}

.copyright {
  margin-top: 10px !important;
}

@media (max-width: 900px) {
  .menu-btn { display: block; }

  .main-nav {
    position: fixed;
    inset: 72px 0 auto;
    max-height: calc(100vh - 72px);
    display: none;
    overflow: auto;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 18px 20px 28px;
    border-bottom: 2px solid var(--ink);
    background: var(--paper);
  }

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

  .main-nav a:not(.download-btn) {
    padding: 14px 0;
    border-bottom: 1px solid var(--line);
  }

  .hero-grid {
    min-height: auto;
    grid-template-columns: 1fr;
    gap: 44px;
    padding-block: 58px 70px;
  }

  .phone-stage { min-height: 440px; }

  .feature-card { grid-column: span 6; }
  .feature-card:nth-child(4),
  .feature-card:nth-child(5) { grid-column: span 6; }

  .showcase-grid { grid-template-columns: repeat(2, 1fr); }
  .screen-card:nth-child(2) { margin-top: 0; }

  .route-grid,
  .home-faq { grid-template-columns: 1fr; }

  .content-layout { grid-template-columns: 1fr; }
  .side-nav { position: static; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-grid > :first-child { grid-column: 1 / -1; }
}

@media (max-width: 620px) {
  .container { width: min(calc(100% - 28px), var(--max)); }
  .nav-wrap { min-height: 66px; }
  .main-nav { inset-block-start: 66px; }
  .hero h1 { font-size: 50px; }
  .hero-grid {
    height: 704px;
    height: clamp(520px, calc(100svh - 140px), 730px);
    overflow: hidden;
  }
  .hero-lead { font-size: 17px; }
  .hero-actions { align-items: stretch; flex-direction: column; }
  .download-btn { width: 100%; }
  .phone-stage { min-height: 400px; }
  .phone-stage::before { width: 270px; height: 270px; }
  .phone-stage::after { width: 295px; height: 120px; }
  .hero-phone { width: 236px; }
  .sticker { width: 78px; height: 78px; font-size: 12px; }
  .section { padding-block: 62px; }
  .section-head { align-items: start; flex-direction: column; gap: 10px; }
  .feature-card,
  .feature-card:nth-child(4),
  .feature-card:nth-child(5) { grid-column: 1 / -1; }
  .showcase-grid { grid-template-columns: 1fr; gap: 42px; }
  .route-card { min-height: 300px; padding: 27px; }
  .proof-strip,
  .review-grid { grid-template-columns: 1fr; }
  .proof-item { border-right: 0; border-bottom: 2px solid var(--ink); }
  .proof-item:last-child { border-bottom: 0; }
  .cta-grid { grid-template-columns: 1fr; }
  .page-hero { padding-block: 56px 50px; }
  .page-hero h1 { font-size: 40px; }
  .content-layout { gap: 38px; padding-block: 48px 70px; }
  .step-card { grid-template-columns: 1fr; }
  .troubleshoot-grid,
  .related { grid-template-columns: 1fr; }
  .inline-download { align-items: stretch; flex-direction: column; }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-grid > :first-child { grid-column: auto; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}