:root {
  --ink: #17211b;
  --paper: #f7f6ef;
  --white: #ffffff;
  --frog: #39b86a;
  --frog-dark: #167a43;
  --lemon: #ffd84a;
  --coral: #f26452;
  --sky: #68bddd;
  --muted: #617068;
  --line: #d9dfd8;
  --shadow: 5px 5px 0 var(--ink);
  --radius: 6px;
  --max: 1160px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 88px;
}

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.menu-open {
  overflow: hidden;
}

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

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

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

.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 1000;
  padding: 8px 12px;
  color: var(--white);
  background: var(--ink);
  transform: translateY(-160%);
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: 72px;
  border-bottom: 2px solid var(--ink);
  background: rgba(247, 246, 239, 0.97);
}

.nav-wrap {
  width: min(var(--max), calc(100% - 32px));
  height: 100%;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

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

.brand img {
  width: 42px;
  height: 42px;
  object-fit: cover;
  border: 2px solid var(--ink);
  border-radius: 50%;
}

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

.site-nav > a:not(.button) {
  min-height: 40px;
  padding: 7px 12px;
  border-bottom: 3px solid transparent;
  font-size: 15px;
  font-weight: 700;
}

.site-nav > a:not(.button):hover,
.site-nav > a[aria-current="page"]:not(.button) {
  border-color: var(--frog);
}

.menu-toggle {
  display: none;
  width: 42px;
  height: 42px;
  padding: 9px;
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background: var(--lemon);
  cursor: pointer;
}

.menu-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  margin: 4px 0;
  background: var(--ink);
}

.button {
  display: inline-flex;
  min-height: 46px;
  align-items: center;
  justify-content: center;
  padding: 10px 22px;
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background: var(--lemon);
  box-shadow: 3px 3px 0 var(--ink);
  font-weight: 900;
  cursor: pointer;
  transition: transform 160ms ease, box-shadow 160ms ease;
}

.button:hover,
.button:focus-visible {
  transform: translate(2px, 2px);
  box-shadow: 1px 1px 0 var(--ink);
}

.button-dark {
  color: var(--white);
  background: var(--ink);
  box-shadow: 3px 3px 0 var(--coral);
}

.button-small {
  min-height: 40px;
  padding: 7px 16px;
  font-size: 14px;
}

.container {
  width: min(var(--max), calc(100% - 36px));
  margin: 0 auto;
}

.hero {
  position: relative;
  min-height: 640px;
  overflow: hidden;
  border-bottom: 2px solid var(--ink);
  background: var(--frog);
}

.hero::before,
.hero::after {
  position: absolute;
  content: "";
  pointer-events: none;
}

.hero::before {
  top: 48px;
  left: -4vw;
  width: 35vw;
  height: 90px;
  border: 2px solid var(--ink);
  background: var(--lemon);
  transform: rotate(-7deg);
}

.hero::after {
  right: -60px;
  bottom: 54px;
  width: 250px;
  height: 120px;
  border: 2px solid var(--ink);
  background: var(--coral);
  transform: rotate(11deg);
}

.hero-inner {
  position: relative;
  z-index: 2;
  display: flex;
  min-height: 640px;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 50px 0 38px;
  text-align: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  padding: 2px 10px;
  border: 2px solid var(--ink);
  border-radius: 999px;
  background: var(--white);
  font-size: 13px;
  font-weight: 900;
}

.hero h1 {
  width: 100%;
  max-width: 900px;
  margin: 14px 0 8px;
  font-size: clamp(46px, 7.5vw, 86px);
  line-height: 1.05;
  font-weight: 950;
  overflow-wrap: anywhere;
  text-wrap: balance;
}

.hero-copy {
  width: 100%;
  max-width: 680px;
  margin: 0;
  font-size: 18px;
  font-weight: 650;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  margin-top: 20px;
}

.hero-note {
  font-size: 13px;
  font-weight: 700;
}

.preview-rail {
  display: grid;
  width: min(720px, 88vw);
  margin-top: 28px;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.preview-tile {
  position: relative;
  overflow: hidden;
  border: 3px solid var(--ink);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: var(--shadow);
  min-width: 0;
}

.preview-tile:nth-child(2) {
  transform: translateY(10px);
}

.preview-tile img,
.app-shot img {
  width: 100%;
  max-width: 400px;
  height: auto;
  aspect-ratio: 1 / 1;
  object-fit: cover;
}

.preview-tile span {
  position: absolute;
  left: 7px;
  bottom: 7px;
  padding: 2px 8px;
  border: 2px solid var(--ink);
  background: var(--lemon);
  font-size: 12px;
  font-weight: 900;
}

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

.ticker-track {
  display: flex;
  width: max-content;
  min-height: 42px;
  align-items: center;
  gap: 28px;
  padding: 0 14px;
  font-size: 13px;
  font-weight: 800;
  white-space: nowrap;
  animation: ticker 24s linear infinite;
}

.ticker-track span::before {
  margin-right: 28px;
  color: var(--lemon);
  content: "◆";
}

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

.section {
  padding: 82px 0;
  border-bottom: 2px solid var(--ink);
}

.section-green {
  background: #dff4e5;
}

.section-yellow {
  background: var(--lemon);
}

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

.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 34px;
}

.section-head h2 {
  max-width: 720px;
  margin: 0;
  font-size: clamp(30px, 4.2vw, 52px);
  line-height: 1.15;
}

.section-index {
  flex: 0 0 auto;
  font-size: 42px;
  font-weight: 950;
  color: var(--frog-dark);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 2px solid var(--ink);
  border-left: 2px solid var(--ink);
}

.feature-item {
  min-height: 230px;
  padding: 26px;
  border-right: 2px solid var(--ink);
  border-bottom: 2px solid var(--ink);
  background: var(--white);
}

.feature-no {
  display: flex;
  width: 42px;
  height: 42px;
  align-items: center;
  justify-content: center;
  border: 2px solid var(--ink);
  border-radius: 50%;
  background: var(--lemon);
  font-weight: 950;
}

.feature-item:nth-child(2) .feature-no,
.feature-item:nth-child(5) .feature-no {
  background: var(--coral);
}

.feature-item h3 {
  margin: 18px 0 8px;
  font-size: 21px;
}

.feature-item p {
  margin: 0;
  color: var(--muted);
  font-size: 15px;
}

.showcase-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
}

.app-shot {
  margin: 0;
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: var(--shadow);
}

.app-shot img {
  margin: 0 auto;
}

.app-shot figcaption {
  min-height: 64px;
  padding: 12px 14px;
  border-top: 2px solid var(--ink);
  font-size: 14px;
  font-weight: 800;
}

.path-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 26px;
}

.path-card {
  position: relative;
  min-height: 320px;
  padding: 32px;
  overflow: hidden;
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: var(--shadow);
}

.path-card:nth-child(2) {
  background: #dff4e5;
}

.path-label {
  font-size: 13px;
  font-weight: 900;
  color: var(--frog-dark);
}

.path-card h3 {
  margin: 20px 0 12px;
  font-size: 32px;
  line-height: 1.2;
}

.path-card ul {
  padding: 0;
  margin: 0 0 24px;
  list-style: none;
}

.path-card li {
  padding: 7px 0;
  border-bottom: 1px dashed var(--line);
}

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

.text-link::after {
  content: "→";
}

.metrics {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border: 2px solid var(--ink);
  background: var(--white);
}

.metric {
  min-height: 140px;
  padding: 24px;
  border-right: 2px solid var(--ink);
}

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

.metric strong {
  display: block;
  font-size: 34px;
  line-height: 1.15;
}

.metric span {
  color: var(--muted);
  font-size: 14px;
  font-weight: 700;
}

.quote-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin-top: 28px;
}

.quote-card {
  margin: 0;
  padding: 24px;
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background: var(--white);
}

.quote-card p {
  margin: 0 0 16px;
  font-size: 16px;
}

.quote-card footer {
  color: var(--frog-dark);
  font-size: 13px;
  font-weight: 900;
}

.faq-list {
  display: grid;
  gap: 12px;
}

.faq-list details {
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background: var(--white);
}

.faq-list summary {
  position: relative;
  padding: 18px 52px 18px 20px;
  font-weight: 900;
  cursor: pointer;
  list-style: none;
}

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

.faq-list summary::after {
  position: absolute;
  top: 50%;
  right: 18px;
  width: 25px;
  height: 25px;
  border: 2px solid var(--ink);
  border-radius: 50%;
  content: "+";
  line-height: 20px;
  text-align: center;
  transform: translateY(-50%);
}

.faq-list details[open] summary::after {
  content: "−";
}

.faq-answer {
  padding: 0 20px 18px;
  color: var(--muted);
}

.faq-answer p {
  margin: 0;
}

.download-band {
  padding: 52px 0;
  border-bottom: 2px solid var(--ink);
  background: var(--coral);
}

.download-band-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}

.download-band h2 {
  margin: 0 0 6px;
  font-size: clamp(28px, 4vw, 46px);
  line-height: 1.15;
}

.download-band p,
.download-band .band-copy {
  margin: 0;
  font-weight: 700;
}

.site-footer {
  padding: 44px 0 30px;
  color: #dce5df;
  background: var(--ink);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr 1fr;
  gap: 36px;
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--white);
  font-size: 20px;
  font-weight: 900;
}

.footer-brand img {
  width: 42px;
  height: 42px;
  border: 2px solid var(--white);
  border-radius: 50%;
}

.footer-grid h3 {
  margin: 0 0 12px;
  color: var(--lemon);
  font-size: 15px;
}

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

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

.disclaimer {
  margin: 34px 0 0;
  padding-top: 20px;
  border-top: 1px solid #475049;
  color: #abb7af;
  font-size: 12px;
}

.copyright {
  margin: 8px 0 0;
  color: #87958c;
  font-size: 12px;
}

.page-hero {
  padding: 70px 0 56px;
  border-bottom: 2px solid var(--ink);
  background: var(--lemon);
}

.page-hero.green {
  background: var(--frog);
}

.page-hero h1 {
  width: 100%;
  max-width: 900px;
  margin: 12px 0 16px;
  font-size: clamp(40px, 6.5vw, 72px);
  line-height: 1.08;
  overflow-wrap: anywhere;
  text-wrap: balance;
}

.page-hero p {
  width: 100%;
  max-width: 760px;
  margin: 0;
  font-size: 18px;
  font-weight: 650;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  font-size: 13px;
  font-weight: 800;
}

.article-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 44px;
  align-items: start;
}

.article-content,
.article-sidebar,
.feature-detail,
.step-card {
  min-width: 0;
}

.article-content h2 {
  margin: 58px 0 22px;
  font-size: 34px;
  line-height: 1.2;
}

.article-content h2:first-child {
  margin-top: 0;
}

.article-content h3 {
  margin: 26px 0 8px;
  font-size: 21px;
}

.article-content p {
  margin: 0 0 16px;
}

.article-content a:not(.button) {
  color: var(--frog-dark);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.step-list {
  display: grid;
  gap: 22px;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: steps;
}

.step-card {
  position: relative;
  padding: 28px 28px 28px 92px;
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background: var(--white);
  counter-increment: steps;
}

.step-card::before {
  position: absolute;
  top: 26px;
  left: 26px;
  display: flex;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  border: 2px solid var(--ink);
  border-radius: 50%;
  background: var(--lemon);
  content: counter(steps, decimal-leading-zero);
  font-weight: 950;
}

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

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

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

.checklist li {
  padding: 16px;
  border-left: 5px solid var(--frog);
  background: #edf7f0;
  font-weight: 700;
}

.notice {
  padding: 20px;
  border: 2px solid var(--ink);
  border-left-width: 10px;
  border-radius: var(--radius);
  background: #fff7d1;
}

.article-sidebar {
  position: sticky;
  top: 96px;
}

.side-panel {
  padding: 22px;
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: var(--shadow);
}

.side-panel + .side-panel {
  margin-top: 22px;
}

.side-panel h2,
.side-panel h3 {
  margin: 0 0 12px;
  font-size: 18px;
}

.side-links {
  display: grid;
  gap: 8px;
}

.side-links a {
  padding: 7px 0;
  border-bottom: 1px dashed var(--line);
  font-size: 14px;
  font-weight: 700;
}

.feature-detail-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}

.feature-detail {
  padding: 24px;
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background: var(--white);
}

.feature-detail:nth-child(3n + 2) {
  background: #edf7f0;
}

.feature-detail:nth-child(3n) {
  background: #fff7d1;
}

.feature-detail h3 {
  margin-top: 0;
}

.trouble-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--white);
}

.trouble-table th,
.trouble-table td {
  padding: 14px;
  border: 2px solid var(--ink);
  text-align: left;
  vertical-align: top;
}

.trouble-table th {
  background: var(--lemon);
}

.back-top {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 80;
  display: none;
  width: 42px;
  height: 42px;
  border: 2px solid var(--ink);
  border-radius: 50%;
  background: var(--lemon);
  box-shadow: 2px 2px 0 var(--ink);
  font-size: 20px;
  font-weight: 900;
  cursor: pointer;
}

.back-top.visible {
  display: block;
}

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

@media (max-width: 900px) {
  .feature-grid,
  .quote-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .metric:nth-child(2) {
    border-right: 0;
  }

  .metric:nth-child(-n + 2) {
    border-bottom: 2px solid var(--ink);
  }

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

  .article-sidebar {
    position: static;
  }
}

@media (max-width: 720px) {
  .site-header {
    height: 66px;
  }

  .nav-wrap {
    width: min(100% - 24px, var(--max));
  }

  .brand {
    font-size: 19px;
  }

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

  .menu-toggle {
    display: block;
  }

  .site-nav {
    position: fixed;
    top: 66px;
    right: 0;
    bottom: 0;
    left: 0;
    display: none;
    padding: 28px 18px;
    flex-direction: column;
    align-items: stretch;
    gap: 8px;
    border-top: 2px solid var(--ink);
    background: var(--paper);
  }

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

  .site-nav > a:not(.button) {
    min-height: 50px;
    padding: 12px 6px;
    border-bottom: 1px solid var(--line);
  }

  .site-nav .button {
    margin-top: 10px;
  }

  .hero,
  .hero-inner {
    min-height: 620px;
  }

  .hero-inner {
    padding: 34px 0 30px;
  }

  .hero h1 {
    max-width: 620px;
    font-size: clamp(40px, 11vw, 58px);
  }

  .hero-copy {
    max-width: 560px;
    font-size: 16px;
  }

  .hero-actions {
    width: min(100%, 480px);
    flex-direction: column;
    gap: 8px;
  }

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

  .hero-note {
    width: 100%;
    overflow-wrap: anywhere;
  }

  .preview-rail {
    width: min(580px, 92vw);
    gap: 8px;
  }

  .preview-tile {
    box-shadow: 3px 3px 0 var(--ink);
  }

  .preview-tile span {
    display: none;
  }

  .section {
    padding: 58px 0;
  }

  .section-head {
    align-items: flex-start;
    flex-direction: column-reverse;
    gap: 8px;
    margin-bottom: 24px;
  }

  .section-index {
    font-size: 26px;
  }

  .feature-grid,
  .showcase-grid,
  .path-grid,
  .quote-grid,
  .footer-grid,
  .feature-detail-grid,
  .checklist {
    grid-template-columns: 1fr;
  }

  .feature-item {
    min-height: auto;
  }

  .showcase-grid {
    max-width: 400px;
    margin: 0 auto;
  }

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

  .metric {
    min-height: 120px;
    padding: 18px;
  }

  .metric strong {
    font-size: 27px;
  }

  .download-band-inner {
    align-items: flex-start;
    flex-direction: column;
  }

  .download-band .button {
    width: 100%;
  }

  .page-hero {
    padding: 50px 0 40px;
  }

  .page-hero h1 {
    font-size: clamp(38px, 12vw, 56px);
  }

  .article-content h2 {
    font-size: 29px;
  }

  .step-card {
    padding: 78px 20px 22px;
  }

  .step-card::before {
    top: 20px;
    left: 20px;
  }

  .trouble-table,
  .trouble-table tbody,
  .trouble-table tr,
  .trouble-table th,
  .trouble-table td {
    display: block;
    width: 100%;
  }

  .trouble-table tr + tr {
    margin-top: 12px;
  }
}

@media (max-width: 430px) {
  .container {
    width: min(var(--max), calc(100% - 24px));
  }

  .hero,
  .hero-inner {
    min-height: 590px;
  }

  .hero-actions {
    width: 100%;
    flex-direction: column;
    gap: 8px;
  }

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

  .hero-note {
    margin-top: 2px;
  }

  .preview-rail {
    margin-top: 18px;
  }

  .path-card {
    min-height: auto;
    padding: 24px;
  }

  .path-card h3 {
    font-size: 27px;
  }
}