:root {
  --ink: #14202b;
  --ink-soft: #52606d;
  --paper: #f7f9f8;
  --white: #ffffff;
  --line: #dce4e7;
  --yellow: #ffd42a;
  --yellow-deep: #e9b900;
  --teal: #1fb6aa;
  --teal-dark: #087f78;
  --coral: #ff6f61;
  --blue: #3777ff;
  --shadow: 0 18px 45px rgba(20, 32, 43, 0.12);
  --container: 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;
  letter-spacing: 0;
}

body.nav-open {
  overflow: hidden;
}

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

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

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

button,
input {
  font: inherit;
}

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

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

.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 999;
  padding: 10px 16px;
  color: var(--white);
  background: var(--ink);
  transform: translateY(-150%);
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid rgba(20, 32, 43, 0.1);
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(14px);
}

.nav-wrap {
  display: flex;
  min-height: 72px;
  align-items: center;
  gap: 28px;
}

.brand {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 900;
}

.brand img {
  width: 44px;
  height: 44px;
  border-radius: 8px;
}

.site-nav {
  display: flex;
  margin-left: auto;
  align-items: center;
  gap: 8px;
}

.site-nav a:not(.button) {
  padding: 10px 13px;
  color: #3c4955;
  font-size: 14px;
  font-weight: 700;
}

.site-nav a:not(.button):hover,
.site-nav a[aria-current="page"] {
  color: var(--ink);
  box-shadow: inset 0 -3px 0 var(--yellow);
}

.menu-toggle {
  display: none;
  width: 44px;
  height: 44px;
  margin-left: auto;
  border: 1px solid var(--line);
  border-radius: 6px;
  color: var(--ink);
  background: var(--white);
  cursor: pointer;
}

.menu-toggle span,
.menu-toggle::before,
.menu-toggle::after {
  display: block;
  width: 20px;
  height: 2px;
  margin: 4px auto;
  background: currentColor;
  content: "";
  transition: transform 180ms ease, opacity 180ms ease;
}

.nav-open .menu-toggle span {
  opacity: 0;
}

.nav-open .menu-toggle::before {
  transform: translateY(6px) rotate(45deg);
}

.nav-open .menu-toggle::after {
  transform: translateY(-6px) rotate(-45deg);
}

.button {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 11px 22px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  color: var(--ink);
  background: var(--yellow);
  box-shadow: 4px 4px 0 var(--ink);
  font-weight: 900;
  line-height: 1.2;
  transition: transform 160ms ease, box-shadow 160ms ease, background 160ms ease;
}

.button:hover {
  background: #ffe164;
  box-shadow: 2px 2px 0 var(--ink);
  transform: translate(2px, 2px);
}

.button.secondary {
  background: var(--white);
  box-shadow: none;
}

.button.compact {
  min-height: 40px;
  padding: 9px 16px;
  box-shadow: none;
  font-size: 14px;
}

.button .button-icon {
  font-size: 20px;
  line-height: 1;
}

.hero {
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--line);
  background: var(--white);
}

.hero::before {
  position: absolute;
  inset: 0 0 auto;
  height: 10px;
  background: var(--yellow);
  content: "";
}

.hero-grid {
  display: grid;
  min-height: min(720px, calc(100vh - 72px));
  align-items: center;
  grid-template-columns: minmax(0, 1.05fr) minmax(360px, 0.95fr);
  gap: 58px;
  padding-block: 78px 64px;
}

.eyebrow {
  display: inline-block;
  margin-bottom: 14px;
  color: var(--teal-dark);
  font-size: 13px;
  font-weight: 900;
  text-transform: uppercase;
}

.hero h1,
.page-hero h1 {
  max-width: 780px;
  margin: 0;
  font-size: clamp(40px, 4.8vw, 68px);
  line-height: 1.06;
  letter-spacing: 0;
}

.hero h1 + p {
  max-width: 670px;
  margin: 24px 0 0;
  color: #44515c;
  font-size: 19px;
  line-height: 1.9;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 30px;
}

.trust-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 24px;
  margin-top: 28px;
  color: #5c6872;
  font-size: 14px;
  font-weight: 700;
}

.trust-row span::before {
  color: var(--teal);
  content: "●";
  margin-right: 8px;
}

.hero-media {
  position: relative;
  display: grid;
  min-height: 580px;
  place-items: center;
}

.hero-panel {
  position: absolute;
  width: 88%;
  height: 88%;
  border: 2px solid var(--ink);
  background: var(--teal);
  transform: rotate(4deg);
}

.hero-panel::after {
  position: absolute;
  inset: 24px;
  border: 2px solid rgba(20, 32, 43, 0.6);
  content: "";
}

.phone-frame {
  position: relative;
  z-index: 2;
  width: min(310px, 76vw);
  padding: 12px;
  border: 3px solid var(--ink);
  border-radius: 38px;
  background: var(--ink);
  box-shadow: var(--shadow);
}

.phone-frame img {
  width: 100%;
  max-width: 400px;
  height: auto;
  border-radius: 28px;
}

.media-note {
  position: absolute;
  z-index: 3;
  right: 0;
  bottom: 68px;
  width: 178px;
  padding: 16px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--yellow);
  box-shadow: 5px 5px 0 var(--ink);
  font-size: 14px;
  font-weight: 900;
  line-height: 1.45;
}

.media-note b {
  display: block;
  font-size: 26px;
}

.fact-strip {
  border-bottom: 1px solid var(--line);
  background: var(--ink);
  color: var(--white);
}

.facts {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
}

.fact {
  min-height: 124px;
  padding: 28px 34px;
  border-right: 1px solid rgba(255, 255, 255, 0.18);
}

.fact:last-child {
  border-right: 0;
}

.fact strong {
  display: block;
  margin-bottom: 2px;
  color: var(--yellow);
  font-size: 25px;
}

.section {
  padding-block: 96px;
}

.section.alt {
  border-block: 1px solid var(--line);
  background: var(--white);
}

.section-head {
  display: flex;
  margin-bottom: 38px;
  align-items: end;
  justify-content: space-between;
  gap: 28px;
}

.section-head h2,
.article-section h2 {
  max-width: 760px;
  margin: 0;
  font-size: clamp(30px, 4vw, 48px);
  line-height: 1.15;
  letter-spacing: 0;
}

.section-head .side-copy {
  max-width: 420px;
  margin: 0;
  color: var(--ink-soft);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.feature-card,
.link-card,
.review-card,
.step-card,
.info-card {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
}

.feature-card {
  min-height: 280px;
  padding: 28px;
  border-top: 5px solid var(--yellow);
}

.feature-card:nth-child(2) {
  border-top-color: var(--teal);
}

.feature-card:nth-child(3) {
  border-top-color: var(--coral);
}

.feature-card:nth-child(4) {
  border-top-color: var(--blue);
}

.feature-card:nth-child(5) {
  border-top-color: var(--yellow);
}

.feature-card:nth-child(6) {
  border-top-color: var(--teal);
}

.feature-number {
  display: inline-grid;
  width: 38px;
  height: 38px;
  margin-bottom: 22px;
  place-items: center;
  border: 2px solid var(--ink);
  border-radius: 50%;
  font-size: 13px;
  font-weight: 900;
}

.feature-card h3,
.link-card h3,
.step-card h3,
.info-card h3 {
  margin: 0 0 10px;
  font-size: 22px;
  line-height: 1.35;
}

.feature-card p,
.link-card p,
.step-card p,
.info-card p {
  margin: 0;
  color: var(--ink-soft);
}

.shots-track {
  display: grid;
  grid-template-columns: repeat(4, minmax(220px, 1fr));
  gap: 18px;
}

.shot-item {
  min-width: 0;
}

.shot-item img {
  width: 100%;
  max-width: 400px;
  height: auto;
  border: 1px solid #d6dde0;
  border-radius: 8px;
  box-shadow: 0 12px 30px rgba(20, 32, 43, 0.1);
}

.shot-item figcaption {
  margin-top: 12px;
  font-size: 14px;
  font-weight: 800;
}

.category-layout {
  display: grid;
  align-items: start;
  grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  gap: 56px;
}

.category-copy {
  position: sticky;
  top: 112px;
}

.category-copy h2 {
  margin: 0;
  font-size: clamp(32px, 4vw, 50px);
  line-height: 1.15;
}

.category-copy p {
  margin: 22px 0 0;
  color: var(--ink-soft);
}

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

.category-row {
  display: grid;
  padding: 25px 0;
  border-bottom: 1px solid var(--line);
  grid-template-columns: 56px 150px 1fr;
  gap: 16px;
}

.category-row .dot {
  width: 20px;
  height: 20px;
  margin-top: 5px;
  border: 2px solid var(--ink);
  border-radius: 50%;
  background: var(--yellow);
}

.category-row:nth-child(2) .dot {
  background: var(--teal);
}

.category-row:nth-child(3) .dot {
  background: var(--coral);
}

.category-row:nth-child(4) .dot {
  background: var(--blue);
}

.category-row strong {
  font-size: 18px;
}

.category-row p {
  margin: 0;
  color: var(--ink-soft);
}

.deep-links {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.link-card {
  position: relative;
  min-height: 250px;
  padding: 34px;
  overflow: hidden;
  transition: transform 180ms ease, box-shadow 180ms ease;
}

.link-card:hover {
  box-shadow: var(--shadow);
  transform: translateY(-4px);
}

.link-card .tag {
  display: inline-block;
  margin-bottom: 34px;
  padding: 5px 10px;
  border: 1px solid var(--ink);
  background: var(--yellow);
  font-size: 12px;
  font-weight: 900;
}

.link-card:nth-child(2) .tag {
  color: var(--white);
  background: var(--teal-dark);
}

.link-arrow {
  position: absolute;
  right: 28px;
  bottom: 24px;
  font-size: 32px;
  font-weight: 400;
}

.review-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.review-card {
  padding: 28px;
}

.review-card blockquote {
  margin: 0 0 24px;
  font-size: 17px;
  font-weight: 700;
}

.review-card footer {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--ink-soft);
  font-size: 14px;
}

.avatar {
  display: inline-grid;
  width: 38px;
  height: 38px;
  place-items: center;
  border-radius: 50%;
  color: var(--white);
  background: var(--ink);
  font-weight: 900;
}

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

.faq-list details {
  border-bottom: 1px solid var(--line);
  background: transparent;
}

.faq-list summary {
  position: relative;
  padding: 22px 52px 22px 0;
  cursor: pointer;
  list-style: none;
  font-size: 18px;
  font-weight: 900;
}

.faq-list summary::-webkit-details-marker {
  display: none;
}

.faq-list summary::after {
  position: absolute;
  top: 18px;
  right: 4px;
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border: 1px solid var(--ink);
  border-radius: 50%;
  content: "+";
  font-size: 22px;
  line-height: 1;
}

.faq-list details[open] summary::after {
  content: "−";
  background: var(--yellow);
}

.faq-answer {
  max-width: 860px;
  padding: 0 54px 24px 0;
  color: var(--ink-soft);
}

.faq-answer p {
  margin: 0 0 12px;
}

.download-band {
  padding-block: 78px;
  color: var(--white);
  background: var(--teal-dark);
}

.download-band .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 34px;
}

.download-band h2 {
  max-width: 720px;
  margin: 0;
  font-size: clamp(32px, 5vw, 58px);
  line-height: 1.1;
}

.download-band p {
  max-width: 680px;
  margin: 14px 0 0;
  color: rgba(255, 255, 255, 0.82);
}

.site-footer {
  padding-block: 42px;
  color: rgba(255, 255, 255, 0.72);
  background: var(--ink);
  font-size: 14px;
}

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

.footer-brand {
  display: inline-flex;
  margin-bottom: 14px;
  align-items: center;
  gap: 10px;
  color: var(--white);
  font-size: 19px;
  font-weight: 900;
}

.footer-brand img {
  width: 38px;
  height: 38px;
  border-radius: 7px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
}

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

.disclaimer {
  max-width: 760px;
  margin: 0 0 12px;
}

.copyright {
  margin: 0;
}

.page-hero {
  position: relative;
  padding-block: 90px 70px;
  overflow: hidden;
  border-bottom: 1px solid var(--line);
  background: var(--white);
}

.page-hero::after {
  position: absolute;
  top: 38px;
  right: 6vw;
  width: 190px;
  height: 190px;
  border: 28px solid var(--yellow);
  border-radius: 50%;
  content: "";
}

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

.page-hero p {
  max-width: 780px;
  margin: 22px 0 0;
  color: var(--ink-soft);
  font-size: 18px;
}

.mobile-break {
  display: none;
}

.breadcrumb {
  margin-bottom: 22px;
  color: var(--ink-soft);
  font-size: 14px;
  font-weight: 700;
}

.breadcrumb a {
  color: var(--teal-dark);
}

.article-shell {
  display: grid;
  grid-template-columns: 250px minmax(0, 1fr);
  gap: 58px;
  padding-block: 70px 100px;
}

.article-nav {
  position: sticky;
  top: 98px;
  align-self: start;
  padding: 22px 0;
  border-block: 2px solid var(--ink);
}

.article-nav strong {
  display: block;
  margin-bottom: 12px;
}

.article-nav a {
  display: block;
  padding: 8px 0;
  color: var(--ink-soft);
  font-size: 14px;
  font-weight: 700;
}

.article-nav a:hover {
  color: var(--teal-dark);
}

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

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

.article-section > h2 + p {
  margin-top: 22px;
}

.steps {
  display: grid;
  margin-top: 30px;
  gap: 16px;
}

.step-card {
  display: grid;
  padding: 26px;
  grid-template-columns: 58px 1fr;
  gap: 18px;
}

.step-index {
  display: grid;
  width: 48px;
  height: 48px;
  place-items: center;
  border: 2px solid var(--ink);
  border-radius: 50%;
  background: var(--yellow);
  font-weight: 900;
}

.check-list,
.plain-list {
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
}

.check-list li,
.plain-list li {
  position: relative;
  margin: 9px 0;
  padding-left: 28px;
}

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

.plain-list li::before {
  position: absolute;
  top: 10px;
  left: 4px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--coral);
  content: "";
}

.article-visual {
  display: grid;
  margin-top: 28px;
  align-items: center;
  grid-template-columns: minmax(0, 0.75fr) minmax(240px, 0.45fr);
  gap: 34px;
  padding: 34px;
  color: var(--white);
  background: var(--ink);
}

.article-visual img {
  width: 100%;
  max-width: 300px;
  justify-self: center;
  border-radius: 8px;
}

.notice {
  margin-top: 24px;
  padding: 22px 24px;
  border-left: 6px solid var(--yellow);
  background: #fff8d8;
}

.notice strong {
  display: block;
  margin-bottom: 6px;
}

.info-grid {
  display: grid;
  margin-top: 26px;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.info-card {
  padding: 26px;
}

.feature-detail {
  display: grid;
  margin-top: 28px;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
}

.feature-detail .info-card:nth-child(odd) {
  border-top: 5px solid var(--teal);
}

.feature-detail .info-card:nth-child(even) {
  border-top: 5px solid var(--coral);
}

.faq-page-list {
  margin-top: 30px;
}

.related-box {
  display: grid;
  padding: 32px;
  border: 2px solid var(--ink);
  background: var(--yellow);
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 24px;
}

.related-box h2 {
  margin: 0;
  font-size: 28px;
}

.related-box p {
  margin: 8px 0 0;
}

.mobile-download {
  display: none;
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 500ms ease, transform 500ms ease;
}

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

@media (max-width: 980px) {
  .menu-toggle {
    display: block;
  }

  .site-nav {
    position: fixed;
    inset: 73px 0 auto;
    display: none;
    padding: 18px 20px 26px;
    border-bottom: 1px solid var(--line);
    background: var(--white);
    box-shadow: 0 24px 34px rgba(20, 32, 43, 0.14);
  }

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

  .site-nav a:not(.button) {
    padding: 12px 6px;
  }

  .hero-grid {
    min-height: auto;
    grid-template-columns: 1fr;
    gap: 30px;
    padding-top: 72px;
  }

  .hero-media {
    min-height: 560px;
  }

  .hero-panel {
    width: min(510px, 90%);
  }

  .media-note {
    right: max(0px, calc(50% - 290px));
  }

  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .shots-track {
    display: flex;
    padding-right: 20px;
    overflow-x: auto;
    scroll-snap-type: x mandatory;
  }

  .shot-item {
    flex: 0 0 min(72vw, 310px);
    scroll-snap-align: start;
  }

  .category-layout,
  .article-shell {
    grid-template-columns: 1fr;
  }

  .category-copy,
  .article-nav {
    position: static;
  }

  .article-nav {
    display: flex;
    flex-wrap: wrap;
    gap: 0 18px;
  }

  .article-nav strong {
    width: 100%;
  }

  .page-hero::after {
    right: -80px;
    opacity: 0.55;
  }
}

@media (max-width: 720px) {
  body {
    padding-bottom: 70px;
  }

  .container {
    width: min(calc(100% - 28px), var(--container));
  }

  .brand span {
    font-size: 18px;
  }

  .hero h1,
  .page-hero h1 {
    font-size: 40px;
  }

  .mobile-break {
    display: block;
  }

  .hero h1 + p,
  .page-hero p {
    font-size: 16px;
  }

  .hero-actions .button {
    width: 100%;
  }

  .hero-actions {
    margin-top: 20px;
  }

  .trust-row {
    margin-top: 16px;
  }

  .hero-grid {
    gap: 8px;
    padding-block: 32px 0;
  }

  .hero-media {
    min-height: 0;
    height: 170px;
    align-items: start;
    overflow: hidden;
  }

  .phone-frame {
    width: 122px;
    padding: 7px;
    border-width: 2px;
    border-radius: 23px;
  }

  .phone-frame img {
    border-radius: 17px;
  }

  .hero-panel {
    width: 205px;
    height: 100px;
  }

  .media-note {
    display: none;
  }

  .facts,
  .feature-grid,
  .deep-links,
  .review-grid,
  .info-grid,
  .feature-detail {
    grid-template-columns: 1fr;
  }

  .fact {
    border-right: 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.18);
  }

  .fact:last-child {
    border-bottom: 0;
  }

  .section {
    padding-block: 68px;
  }

  .section-head {
    align-items: start;
    flex-direction: column;
    margin-bottom: 28px;
  }

  .category-row {
    grid-template-columns: 32px 1fr;
  }

  .category-row p {
    grid-column: 2;
  }

  .download-band .container,
  .footer-grid,
  .related-box {
    display: grid;
    grid-template-columns: 1fr;
  }

  .footer-links {
    justify-content: flex-start;
  }

  .page-hero {
    padding-block: 62px 52px;
  }

  .article-shell {
    padding-block: 48px 72px;
    gap: 34px;
  }

  .article-section {
    margin-bottom: 54px;
  }

  .step-card {
    grid-template-columns: 1fr;
  }

  .article-visual {
    grid-template-columns: 1fr;
    padding: 24px;
  }

  .mobile-download {
    position: fixed;
    z-index: 90;
    right: 0;
    bottom: 0;
    left: 0;
    display: flex;
    min-height: 64px;
    padding: 8px 14px;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    border-top: 1px solid var(--line);
    background: var(--white);
    box-shadow: 0 -8px 24px rgba(20, 32, 43, 0.12);
  }

  .mobile-download strong {
    display: block;
    font-size: 15px;
    line-height: 1.2;
  }

  .mobile-download small {
    color: var(--ink-soft);
  }
}

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

  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }

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