:root {
  --ink: #17181b;
  --paper: #fff8e8;
  --white: #ffffff;
  --red: #ef4035;
  --red-dark: #c92d25;
  --teal: #16a39a;
  --teal-dark: #0b7c75;
  --yellow: #ffcf3e;
  --muted: #67635c;
  --line: #ded8ca;
  --soft: #f4efe3;
  --max: 1180px;
  --shadow: 8px 8px 0 rgba(23, 24, 27, 0.14);
}

* {
  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::before {
  position: fixed;
  inset: 0;
  z-index: -2;
  background-image: radial-gradient(rgba(23, 24, 27, 0.09) 0.7px, transparent 0.7px);
  background-size: 13px 13px;
  content: "";
  pointer-events: none;
}

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

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

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

.skip-link {
  position: absolute;
  left: 12px;
  top: -80px;
  z-index: 100;
  padding: 10px 16px;
  background: var(--ink);
  color: var(--white);
}

.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: 3px solid var(--ink);
  background: rgba(255, 248, 232, 0.97);
}

.nav-wrap {
  min-height: 76px;
  display: flex;
  align-items: center;
  gap: 28px;
}

.brand {
  display: inline-flex;
  align-items: center;
  flex-shrink: 0;
  gap: 11px;
  font-size: 20px;
  font-weight: 900;
}

.brand img {
  width: 44px;
  height: 44px;
  border: 2px solid var(--ink);
  border-radius: 7px;
}

.nav-links {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav-links a {
  min-height: 42px;
  padding: 7px 14px;
  display: inline-flex;
  align-items: center;
  border-bottom: 3px solid transparent;
  font-weight: 700;
}

.nav-links a:hover,
.nav-links a[aria-current="page"] {
  border-color: var(--red);
  color: var(--red-dark);
}

.download-btn {
  min-height: 48px;
  padding: 10px 22px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 3px solid var(--ink);
  border-radius: 7px;
  background: var(--teal);
  box-shadow: 5px 5px 0 var(--ink);
  color: var(--white);
  font-weight: 900;
  text-align: center;
  transition: transform 160ms ease, box-shadow 160ms ease, background 160ms ease;
}

.download-btn:hover,
.download-btn:focus-visible {
  background: var(--teal-dark);
  box-shadow: 2px 2px 0 var(--ink);
  transform: translate(3px, 3px);
}

.download-btn:focus-visible,
.nav-toggle:focus-visible,
.faq-question:focus-visible,
a:focus-visible {
  outline: 3px solid var(--yellow);
  outline-offset: 3px;
}

.nav-cta {
  min-height: 42px;
  padding: 7px 17px;
  box-shadow: 4px 4px 0 var(--ink);
}

.nav-toggle {
  width: 44px;
  height: 44px;
  margin-left: auto;
  display: none;
  place-items: center;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--white);
  color: var(--ink);
  cursor: pointer;
}

.nav-toggle span,
.nav-toggle span::before,
.nav-toggle span::after {
  width: 21px;
  height: 3px;
  display: block;
  background: currentColor;
  content: "";
}

.nav-toggle span::before {
  transform: translateY(-7px);
}

.nav-toggle span::after {
  transform: translateY(4px);
}

.hero {
  min-height: 590px;
  overflow: hidden;
  border-bottom: 3px solid var(--ink);
  background: var(--paper);
}

.hero-grid {
  min-height: 590px;
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  align-items: center;
  gap: 64px;
}

.eyebrow {
  width: fit-content;
  margin: 0 0 18px;
  padding: 4px 12px;
  border: 2px solid var(--ink);
  background: var(--yellow);
  font-size: 14px;
  font-weight: 900;
}

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

h1,
h2,
h3 {
  line-height: 1.25;
  letter-spacing: 0;
}

h1 {
  max-width: 700px;
  margin-bottom: 24px;
  font-size: clamp(42px, 7vw, 76px);
  font-weight: 950;
}

h2 {
  margin-bottom: 28px;
  font-size: clamp(29px, 4vw, 45px);
  font-weight: 950;
}

h3 {
  margin-bottom: 12px;
  font-size: 21px;
  font-weight: 900;
}

.hero-copy {
  max-width: 620px;
  margin-bottom: 28px;
  color: #42403b;
  font-size: 18px;
}

.hero-actions {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 22px;
}

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

.trust-row {
  margin: 34px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  list-style: none;
}

.trust-row li {
  padding: 6px 11px;
  border: 2px solid var(--ink);
  border-radius: 5px;
  background: var(--white);
  font-size: 13px;
  font-weight: 800;
}

.hero-visual {
  position: relative;
  min-height: 520px;
  display: grid;
  place-items: center;
}

.hero-visual > .phone-frame {
  width: min(270px, 78%);
}

.hero-visual::before,
.hero-visual::after {
  position: absolute;
  border: 3px solid var(--ink);
  content: "";
}

.hero-visual::before {
  width: 220px;
  height: 310px;
  left: 10px;
  top: 92px;
  background: var(--teal);
  transform: rotate(-9deg);
}

.hero-visual::after {
  width: 190px;
  height: 270px;
  right: 4px;
  bottom: 74px;
  background: var(--yellow);
  transform: rotate(8deg);
}

.phone-frame {
  position: relative;
  z-index: 2;
  width: min(340px, 88%);
  padding: 10px;
  border: 4px solid var(--ink);
  border-radius: 38px;
  background: var(--ink);
  box-shadow: 12px 14px 0 rgba(23, 24, 27, 0.2);
}

.phone-frame img,
.app-preview {
  width: 100%;
  max-width: 400px;
  height: auto;
  border-radius: 27px;
}

.section {
  padding: 96px 0;
}

.section-dark {
  border-block: 3px solid var(--ink);
  background: var(--ink);
  color: var(--paper);
}

.section-white {
  border-block: 3px solid var(--ink);
  background: var(--white);
}

.section-red {
  border-block: 3px solid var(--ink);
  background: var(--red);
  color: var(--white);
}

.section-label {
  margin-bottom: 12px;
  color: var(--red-dark);
  font-size: 14px;
  font-weight: 950;
  text-transform: uppercase;
}

.section-dark .section-label,
.section-red .section-label {
  color: var(--yellow);
}

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

.feature-item {
  min-height: 260px;
  padding: 26px;
  border: 3px solid var(--ink);
  border-radius: 7px;
  background: var(--white);
  box-shadow: var(--shadow);
}

.feature-item:nth-child(2) {
  background: #e7f5f3;
}

.feature-item:nth-child(3) {
  background: #fff2bd;
}

.feature-item:nth-child(4) {
  background: #ffe4df;
}

.feature-no {
  margin-bottom: 34px;
  display: block;
  color: var(--red);
  font-size: 38px;
  font-weight: 950;
  line-height: 1;
}

.feature-item p,
.route-card p,
.review p,
.step-body p,
.article-copy p,
.help-card p {
  color: var(--muted);
}

.preview-layout {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  align-items: end;
  gap: 34px;
}

.preview-card {
  margin: 0;
  display: grid;
  justify-items: center;
}

.preview-card:nth-child(2) {
  transform: translateY(-34px);
}

.preview-card .phone-frame {
  width: min(300px, 100%);
}

.preview-card figcaption {
  margin-top: 22px;
  color: #ded9ce;
  text-align: center;
  font-size: 14px;
}

.preview-card figcaption strong {
  display: block;
  color: var(--white);
  font-size: 18px;
}

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

.route-card {
  min-height: 270px;
  padding: 34px;
  display: flex;
  flex-direction: column;
  border: 3px solid var(--ink);
  border-radius: 7px;
  background: var(--white);
}

.route-card:first-child {
  border-top: 13px solid var(--teal);
}

.route-card:last-child {
  border-top: 13px solid var(--red);
}

.route-link {
  width: fit-content;
  margin-top: auto;
  border-bottom: 3px solid var(--ink);
  font-weight: 900;
}

.route-link:hover {
  color: var(--red-dark);
  border-color: var(--red-dark);
}

.stats-reviews {
  display: grid;
  grid-template-columns: 0.75fr 1.25fr;
  gap: 52px;
  align-items: start;
}

.stat-stack {
  display: grid;
  gap: 14px;
}

.stat {
  padding: 20px;
  border: 3px solid var(--paper);
}

.stat strong {
  display: block;
  color: var(--yellow);
  font-size: 35px;
  line-height: 1.2;
}

.stat span {
  color: #c9c4b8;
  font-size: 14px;
}

.review-list {
  display: grid;
  gap: 14px;
}

.review {
  padding: 21px 24px;
  border-left: 6px solid var(--red);
  background: var(--paper);
  color: var(--ink);
}

.review p {
  margin-bottom: 10px;
}

.review footer {
  color: var(--ink);
  font-size: 13px;
  font-weight: 800;
}

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

.help-card {
  padding: 24px;
  border-top: 5px solid var(--red);
  background: var(--white);
}

.text-link {
  color: var(--red-dark);
  font-weight: 900;
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 4px;
}

.bottom-cta {
  padding: 72px 0;
  border-top: 3px solid var(--ink);
  background: var(--yellow);
}

.bottom-cta-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 36px;
}

.bottom-cta h2 {
  max-width: 680px;
  margin-bottom: 8px;
}

.bottom-cta p {
  margin-bottom: 0;
  color: #49453e;
}

.site-footer {
  padding: 54px 0 30px;
  background: var(--ink);
  color: var(--paper);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 50px;
}

.footer-brand {
  margin-bottom: 18px;
}

.footer-copy {
  max-width: 620px;
  color: #bbb6ab;
  font-size: 14px;
}

.footer-links {
  display: flex;
  justify-content: flex-end;
  flex-wrap: wrap;
  gap: 18px;
}

.footer-links a {
  color: var(--paper);
  font-weight: 700;
}

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

.disclaimer {
  margin: 32px 0 0;
  padding-top: 24px;
  border-top: 1px solid #494a4d;
  color: #99968f;
  font-size: 13px;
}

.copyright {
  margin-top: 10px;
  color: #77746e;
  font-size: 12px;
}

/* Inner pages */
.page-hero {
  padding: 86px 0 72px;
  border-bottom: 3px solid var(--ink);
  background: var(--teal);
}

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

.page-hero h1 {
  max-width: 880px;
  margin-bottom: 18px;
  font-size: clamp(38px, 6vw, 66px);
}

.page-hero p {
  max-width: 760px;
  margin-bottom: 0;
  font-size: 18px;
}

.page-hero .eyebrow {
  background: var(--paper);
  color: var(--ink);
}

.guide-shell {
  display: grid;
  grid-template-columns: 250px minmax(0, 1fr);
  align-items: start;
  gap: 54px;
}

.toc {
  position: sticky;
  top: 102px;
  padding: 20px;
  border: 3px solid var(--ink);
  background: var(--white);
}

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

.toc a {
  padding: 7px 0;
  display: block;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 14px;
}

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

.steps {
  display: grid;
  gap: 34px;
}

.step {
  display: grid;
  grid-template-columns: 86px 1fr;
  gap: 24px;
  scroll-margin-top: 110px;
}

.step-index {
  width: 72px;
  height: 72px;
  display: grid;
  place-items: center;
  border: 3px solid var(--ink);
  border-radius: 50%;
  background: var(--yellow);
  font-size: 27px;
  font-weight: 950;
}

.step-body {
  padding: 26px 28px;
  border: 3px solid var(--ink);
  border-radius: 7px;
  background: var(--white);
}

.step-body ul,
.article-copy ul {
  margin: 0;
  padding-left: 21px;
}

.step-body li,
.article-copy li {
  margin-bottom: 8px;
}

.notice {
  margin: 24px 0;
  padding: 20px 22px;
  border-left: 7px solid var(--red);
  background: #ffe5df;
  color: #3d2825;
}

.guide-download {
  margin-top: 22px;
}

.article-copy {
  max-width: 860px;
  margin-inline: auto;
}

.article-copy h2 {
  margin-top: 68px;
  padding-bottom: 12px;
  border-bottom: 3px solid var(--ink);
  font-size: 34px;
  scroll-margin-top: 105px;
}

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

.article-copy h3 {
  margin-top: 30px;
}

.function-band {
  margin: 30px 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border: 3px solid var(--ink);
  background: var(--white);
}

.function-band div {
  min-height: 152px;
  padding: 22px;
  border-right: 2px solid var(--ink);
}

.function-band div:last-child {
  border-right: 0;
}

.function-band strong {
  display: block;
  margin-bottom: 6px;
  color: var(--red-dark);
  font-size: 18px;
}

.faq-list {
  border-top: 3px solid var(--ink);
}

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

.faq-question {
  width: 100%;
  padding: 22px 58px 22px 20px;
  position: relative;
  border: 0;
  background: transparent;
  color: var(--ink);
  font: inherit;
  font-size: 18px;
  font-weight: 900;
  text-align: left;
  cursor: pointer;
}

.faq-question::after {
  position: absolute;
  top: 20px;
  right: 20px;
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  border: 2px solid var(--ink);
  border-radius: 50%;
  content: "+";
  font-size: 22px;
  line-height: 1;
}

.faq-question[aria-expanded="true"]::after {
  content: "−";
  background: var(--yellow);
}

.faq-answer {
  padding: 0 58px 23px 20px;
  color: var(--muted);
}

.faq-answer[hidden] {
  display: none;
}

.related {
  margin-top: 70px;
  padding: 30px;
  border: 3px solid var(--ink);
  background: var(--yellow);
}

.related h2 {
  margin: 0 0 12px;
  padding: 0;
  border: 0;
  font-size: 27px;
}

.related p {
  margin-bottom: 0;
  color: #403d37;
}

.related a {
  font-weight: 900;
  text-decoration: underline;
  text-underline-offset: 4px;
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 460ms ease, transform 460ms ease;
}

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

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

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

@media (max-width: 960px) {
  .feature-grid {
    grid-template-columns: 1fr 1fr;
  }

  .hero-grid {
    gap: 24px;
  }

  .preview-layout {
    gap: 18px;
  }

  .guide-shell {
    grid-template-columns: 1fr;
  }

  .toc {
    position: static;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 4px 16px;
  }

  .toc strong {
    grid-column: 1 / -1;
  }
}

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

  .nav-wrap {
    min-height: 68px;
  }

  .nav-toggle {
    display: grid;
  }

  .nav-links {
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    padding: 12px 14px 20px;
    display: none;
    align-items: stretch;
    flex-direction: column;
    border-bottom: 3px solid var(--ink);
    background: var(--paper);
  }

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

  .nav-links a {
    justify-content: center;
  }

  .nav-cta {
    margin-left: 0;
  }

  .hero,
  .hero-grid {
    min-height: auto;
    max-height: none;
  }

  .hero-grid {
    padding: 44px 0 52px;
    grid-template-columns: 1fr;
  }

  h1 {
    font-size: 44px;
  }

  .hero-visual {
    min-height: 470px;
  }

  .hero-visual::before {
    width: 150px;
    height: 220px;
  }

  .hero-visual::after {
    width: 130px;
    height: 190px;
  }

  .section {
    padding: 72px 0;
  }

  .preview-layout,
  .route-grid,
  .stats-reviews,
  .mini-faq,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .preview-card:nth-child(2) {
    transform: none;
  }

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

  .bottom-cta-inner {
    align-items: flex-start;
    flex-direction: column;
  }

  .bottom-cta-inner .download-btn {
    width: 100%;
  }

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

  .function-band {
    grid-template-columns: 1fr;
  }

  .function-band div {
    border-right: 0;
    border-bottom: 2px solid var(--ink);
  }

  .function-band div:last-child {
    border-bottom: 0;
  }
}

@media (max-width: 520px) {
  .brand {
    font-size: 18px;
  }

  .brand img {
    width: 40px;
    height: 40px;
  }

  h1 {
    font-size: 39px;
  }

  h2 {
    font-size: 31px;
  }

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

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

  .feature-item {
    min-height: 0;
  }

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

  .step-index {
    width: 58px;
    height: 58px;
    font-size: 22px;
  }

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

  .page-hero {
    padding: 62px 0 56px;
  }

  .article-copy h2 {
    font-size: 28px;
  }
}