:root {
  --ink: #17232a;
  --muted: #5c6a70;
  --paper: #f5f7f8;
  --white: #ffffff;
  --line: #d8e0e2;
  --teal: #0f8f83;
  --teal-dark: #0b6e66;
  --coral: #ff5d5d;
  --yellow: #f5c451;
  --cyan: #58c3e5;
  --shadow: 0 16px 38px rgba(23, 35, 42, 0.11);
  --max: 1160px;
}

* {
  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 {
  font: inherit;
}

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

.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 1000;
  padding: 8px 14px;
  color: var(--white);
  background: var(--ink);
  transform: translateY(-160%);
}

.skip-link:focus {
  transform: none;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  min-height: 72px;
  border-bottom: 1px solid rgba(216, 224, 226, 0.9);
  background: rgba(245, 247, 248, 0.96);
  backdrop-filter: blur(12px);
}

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

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
  font-weight: 900;
  font-size: 21px;
}

.brand img {
  width: 40px;
  height: 40px;
  border-radius: 6px;
}

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

.nav-menu a:not(.button) {
  padding: 9px 13px;
  color: #39474d;
  font-size: 14px;
  font-weight: 700;
}

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

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

.menu-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  margin: 4px auto;
  background: var(--ink);
}

.button {
  display: inline-flex;
  min-height: 46px;
  align-items: center;
  justify-content: center;
  padding: 10px 20px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  color: var(--white);
  background: var(--ink);
  box-shadow: 4px 4px 0 var(--yellow);
  font-weight: 800;
  line-height: 1.2;
  transition: transform 160ms ease, box-shadow 160ms ease, background 160ms ease;
}

.button:hover {
  color: var(--white);
  background: var(--teal-dark);
  box-shadow: 2px 2px 0 var(--yellow);
  transform: translate(2px, 2px);
}

.button-secondary {
  color: var(--ink);
  background: var(--white);
  box-shadow: 4px 4px 0 var(--cyan);
}

.button-secondary:hover {
  color: var(--ink);
  background: #edf9f8;
  box-shadow: 2px 2px 0 var(--cyan);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
  color: var(--teal-dark);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: 0;
  text-transform: uppercase;
}

.eyebrow::before {
  width: 28px;
  height: 4px;
  background: var(--coral);
  content: "";
}

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

.hero::after {
  position: absolute;
  right: -40px;
  bottom: 35px;
  width: 22vw;
  max-width: 290px;
  height: 22px;
  background: var(--yellow);
  content: "";
  transform: rotate(-8deg);
}

.hero-grid {
  display: grid;
  min-height: 660px;
  grid-template-columns: 1.08fr 0.92fr;
  align-items: center;
  gap: 72px;
  padding-block: 36px 44px;
}

.hero-copy {
  position: relative;
  z-index: 2;
  min-width: 0;
}

.hero h1 {
  max-width: 720px;
  margin: 0 0 20px;
  font-size: clamp(42px, 7vw, 82px);
  line-height: 1.04;
  letter-spacing: 0;
  overflow-wrap: anywhere;
}

.title-line {
  display: block;
}

.hero-lead {
  max-width: 650px;
  margin: 0 0 26px;
  color: #3f4e54;
  font-size: 19px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-bottom: 28px;
}

.quick-facts {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  margin: 0;
  padding: 0;
  color: var(--muted);
  font-size: 13px;
  list-style: none;
}

.quick-facts li::before {
  margin-right: 7px;
  color: var(--teal);
  content: "●";
}

.hero-visual {
  position: relative;
  z-index: 2;
  display: flex;
  min-height: 560px;
  align-items: center;
  justify-content: center;
}

.hero-screen {
  width: min(100%, 272px);
  max-width: 400px;
  height: auto;
  border: 10px solid var(--ink);
  border-radius: 28px;
  background: var(--white);
  box-shadow: 18px 22px 0 var(--cyan), var(--shadow);
  transform: rotate(2deg);
}

.hero-stamp {
  position: absolute;
  top: 42px;
  right: 2px;
  display: grid;
  width: 116px;
  height: 116px;
  place-items: center;
  border: 3px solid var(--ink);
  border-radius: 50%;
  color: var(--ink);
  background: var(--yellow);
  font-size: 13px;
  font-weight: 900;
  line-height: 1.25;
  text-align: center;
  transform: rotate(8deg);
}

.section {
  padding-block: 92px;
}

#features {
  border-top: 10px solid var(--yellow);
}

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

.section-dark {
  color: var(--white);
  background: var(--ink);
}

.section-head {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 30px;
  margin-bottom: 42px;
}

.section-head h2,
.content-heading {
  max-width: 760px;
  margin: 0;
  font-size: clamp(30px, 4vw, 50px);
  line-height: 1.15;
  letter-spacing: 0;
}

.section-index {
  color: var(--coral);
  font-size: 13px;
  font-weight: 900;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  border: 1px solid var(--line);
  background: var(--line);
}

.feature-item {
  min-height: 260px;
  padding: 28px;
  background: var(--white);
}

.feature-number {
  display: grid;
  width: 40px;
  height: 40px;
  margin-bottom: 44px;
  place-items: center;
  border: 2px solid var(--ink);
  border-radius: 50%;
  color: var(--ink);
  background: var(--yellow);
  font-size: 13px;
  font-weight: 900;
}

.feature-item:nth-child(2) .feature-number {
  background: var(--cyan);
}

.feature-item:nth-child(3) .feature-number {
  background: var(--coral);
}

.feature-item h3 {
  margin: 0 0 10px;
  font-size: 21px;
}

.feature-item p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.screen-stage {
  overflow: hidden;
}

.screen-toolbar {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  margin-bottom: 18px;
}

.rail-control {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 50%;
  color: var(--ink);
  background: var(--white);
  cursor: pointer;
}

.rail-control:hover {
  border-color: var(--ink);
  background: var(--yellow);
}

.screen-rail {
  display: flex;
  gap: 22px;
  overflow-x: auto;
  padding: 8px 6px 28px;
  scroll-behavior: smooth;
  scroll-snap-type: x mandatory;
  scrollbar-color: var(--teal) var(--line);
}

.screen-card {
  flex: 0 0 min(74vw, 286px);
  scroll-snap-align: start;
}

.screen-card img {
  width: 100%;
  max-width: 400px;
  height: auto;
  border: 7px solid var(--ink);
  border-radius: 20px;
  background: var(--white);
  box-shadow: 10px 10px 0 var(--cyan);
}

.screen-card:nth-child(2n) img {
  box-shadow: 10px 10px 0 var(--yellow);
}

.screen-card:nth-child(3n) img {
  box-shadow: 10px 10px 0 var(--coral);
}

.screen-card h3 {
  margin: 20px 0 2px;
  font-size: 17px;
}

.screen-card p {
  margin: 0;
  color: var(--muted);
  font-size: 13px;
}

.path-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.path-card {
  position: relative;
  min-height: 340px;
  overflow: hidden;
  padding: 38px;
  border: 2px solid var(--ink);
  border-radius: 8px;
  background: var(--white);
}

.path-card::after {
  position: absolute;
  right: -24px;
  bottom: -44px;
  color: rgba(23, 35, 42, 0.06);
  font-size: 190px;
  font-weight: 900;
  line-height: 1;
  content: attr(data-mark);
}

.path-card.alt {
  color: var(--white);
  background: var(--teal-dark);
}

.path-card.alt::after {
  color: rgba(255, 255, 255, 0.08);
}

.path-card h3 {
  position: relative;
  z-index: 1;
  max-width: 420px;
  margin: 0 0 18px;
  font-size: 31px;
  line-height: 1.2;
}

.path-card ul {
  position: relative;
  z-index: 1;
  margin: 0 0 28px;
  padding-left: 20px;
}

.text-link {
  position: relative;
  z-index: 1;
  display: inline-block;
  border-bottom: 3px solid var(--coral);
  font-weight: 900;
}

.alt .text-link {
  border-bottom-color: var(--yellow);
}

.metrics {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-block: 1px solid rgba(255, 255, 255, 0.18);
}

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

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

.metric strong {
  display: block;
  color: var(--yellow);
  font-size: 46px;
  line-height: 1.1;
}

.metric span {
  color: #cdd8dc;
  font-size: 13px;
}

.quote-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin-top: 38px;
}

.quote-card {
  margin: 0;
  padding: 26px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 6px;
  background: #223239;
}

.quote-card p {
  margin: 0 0 20px;
  color: #eef4f5;
}

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

.faq-list {
  border-top: 1px solid var(--line);
}

.faq-item {
  border-bottom: 1px solid var(--line);
}

.faq-question {
  display: flex;
  width: 100%;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 22px 0;
  border: 0;
  color: var(--ink);
  background: transparent;
  font-weight: 800;
  text-align: left;
  cursor: pointer;
}

.faq-question::after {
  flex: 0 0 auto;
  font-size: 24px;
  content: "+";
}

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

.faq-answer {
  max-width: 850px;
  padding: 0 50px 22px 0;
  color: var(--muted);
}

.faq-answer p {
  margin: 0;
}

.download-band {
  padding-block: 68px;
  border-block: 2px solid var(--ink);
  background: var(--yellow);
}

.download-band-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 40px;
}

.download-band h2 {
  max-width: 720px;
  margin: 0;
  font-size: clamp(30px, 4vw, 48px);
  line-height: 1.15;
}

.site-footer {
  padding-block: 48px 26px;
  color: #d6dfe2;
  background: var(--ink);
}

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

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

.footer-copy,
.disclaimer,
.copyright {
  color: #aebdc2;
  font-size: 13px;
}

.footer-links strong {
  display: block;
  margin-bottom: 10px;
  color: var(--white);
}

.footer-links a {
  display: block;
  width: max-content;
  margin: 7px 0;
  color: #c9d4d7;
  font-size: 14px;
}

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

.disclaimer {
  margin: 34px 0 18px;
  padding-top: 22px;
  border-top: 1px solid rgba(255, 255, 255, 0.15);
}

.copyright {
  margin: 0;
}

.subhero {
  padding-block: 76px 64px;
  border-bottom: 2px solid var(--ink);
  background: var(--white);
}

.subhero-grid {
  display: grid;
  grid-template-columns: 1fr 340px;
  align-items: end;
  gap: 70px;
}

.subhero-grid > * {
  min-width: 0;
}

.subhero h1 {
  max-width: 820px;
  margin: 0 0 18px;
  font-size: clamp(40px, 6vw, 72px);
  line-height: 1.06;
  letter-spacing: 0;
  overflow-wrap: anywhere;
}

.subhero-lead {
  max-width: 760px;
  margin: 0;
  color: var(--muted);
  font-size: 18px;
}

.subhero-panel {
  padding: 26px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--yellow);
  box-shadow: 8px 8px 0 var(--ink);
}

.subhero-panel strong {
  display: block;
  margin-bottom: 8px;
  font-size: 22px;
}

.subhero-panel span {
  display: block;
  font-size: 13px;
}

.article-layout {
  display: grid;
  grid-template-columns: 240px minmax(0, 1fr);
  gap: 66px;
  padding-block: 72px 100px;
}

.toc {
  position: sticky;
  top: 98px;
  align-self: start;
  padding: 22px;
  border-left: 5px solid var(--teal);
  background: var(--white);
}

.toc strong {
  display: block;
  margin-bottom: 10px;
}

.toc a {
  display: block;
  padding: 5px 0;
  color: var(--muted);
  font-size: 13px;
}

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

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

.article-content h2 {
  margin: 0 0 28px;
  font-size: clamp(29px, 4vw, 44px);
  line-height: 1.2;
}

.article-content h3 {
  margin: 30px 0 10px;
  font-size: 21px;
}

.article-content p {
  margin: 0 0 16px;
  color: #3d4b50;
}

.article-content a:not(.button) {
  color: var(--teal-dark);
  border-bottom: 1px solid currentColor;
  font-weight: 700;
}

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

.step {
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 22px;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--white);
  counter-increment: steps;
}

.step::before {
  display: grid;
  width: 58px;
  height: 58px;
  place-items: center;
  border: 2px solid var(--ink);
  border-radius: 50%;
  background: var(--yellow);
  font-size: 20px;
  font-weight: 900;
  content: counter(steps, decimal-leading-zero);
}

.step h3 {
  margin-top: 0;
}

.inline-shot {
  width: min(100%, 360px);
  max-width: 400px;
  height: auto;
  margin: 26px auto;
  border: 7px solid var(--ink);
  border-radius: 20px;
  box-shadow: 10px 10px 0 var(--cyan);
}

.note {
  margin: 24px 0;
  padding: 20px 22px;
  border-left: 5px solid var(--coral);
  background: #fff3f3;
}

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

.check-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin: 22px 0;
  padding: 0;
  list-style: none;
}

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

.check-list li::before {
  margin-right: 8px;
  color: var(--teal);
  content: "✓";
  font-weight: 900;
}

.function-table {
  width: 100%;
  margin: 24px 0;
  border-collapse: collapse;
  background: var(--white);
}

.function-table th,
.function-table td {
  padding: 15px 16px;
  border: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.function-table th {
  color: var(--white);
  background: var(--teal-dark);
}

.trouble-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.trouble-card {
  padding: 24px;
  border: 1px solid var(--line);
  border-top: 5px solid var(--coral);
  border-radius: 6px;
  background: var(--white);
}

.trouble-card h3 {
  margin-top: 0;
}

.trouble-card p:last-child {
  margin-bottom: 0;
}

.related {
  padding: 28px;
  border: 2px solid var(--ink);
  background: var(--yellow);
}

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

.mobile-download {
  display: none;
}

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

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

@media (max-width: 920px) {
  .nav-wrap {
    gap: 12px;
  }

  .menu-toggle {
    display: block;
    margin-left: auto;
  }

  .nav-menu {
    position: fixed;
    inset: 72px 0 auto;
    display: none;
    align-items: stretch;
    padding: 18px 20px 28px;
    border-bottom: 2px solid var(--ink);
    background: var(--paper);
    box-shadow: var(--shadow);
  }

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

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

  .desktop-download {
    display: none;
  }

  .hero-grid,
  .subhero-grid {
    grid-template-columns: 1fr;
  }

  .hero-grid {
    gap: 28px;
    padding-top: 54px;
  }

  .hero-visual {
    min-height: 500px;
  }

  .hero-stamp {
    right: 9%;
  }

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

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

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

  .toc {
    position: static;
  }
}

@media (max-width: 640px) {
  body {
    font-size: 15px;
  }

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

  .hero {
    min-height: auto;
  }

  .hero-grid {
    min-height: auto;
    padding-block: 36px 52px;
  }

  .hero h1 {
    font-size: 42px;
  }

  .hero-lead {
    font-size: 16px;
  }

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

  .hero-visual {
    height: 210px;
    min-height: 210px;
    align-items: flex-start;
    overflow: hidden;
  }

  .hero-screen {
    width: 182px;
    border-width: 7px;
    border-radius: 21px;
    box-shadow: 12px 14px 0 var(--cyan), var(--shadow);
  }

  .hero-stamp {
    top: 18px;
    right: 8%;
    width: 72px;
    height: 72px;
    font-size: 9px;
  }

  .section {
    padding-block: 66px;
  }

  .section-head {
    display: block;
    margin-bottom: 30px;
  }

  .section-index {
    display: block;
    margin-top: 12px;
  }

  .feature-grid,
  .path-grid,
  .metrics,
  .footer-grid,
  .check-list,
  .trouble-grid {
    grid-template-columns: 1fr;
  }

  .feature-item {
    min-height: 220px;
  }

  .path-card {
    min-height: 320px;
    padding: 28px;
  }

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

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

  .download-band-inner {
    display: block;
  }

  .download-band .button {
    width: 100%;
    margin-top: 24px;
  }

  .subhero {
    padding-block: 52px;
  }

  .subhero h1 {
    font-size: 39px;
  }

  .subhero-panel {
    margin-right: 8px;
  }

  .article-layout {
    gap: 42px;
    padding-block: 50px 72px;
  }

  .step {
    grid-template-columns: 1fr;
    padding: 22px;
  }

  .function-table {
    display: block;
    overflow-x: auto;
  }

  .mobile-download {
    display: none;
  }
}

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

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }

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