:root {
  --paper: #fcfcf7;
  --surface: #ffffff;
  --ink: #27241f;
  --muted: #68645e;
  --line: #27241f;
  --yellow: #f5b700;
  --yellow-soft: #fff2b8;
  --red: #e7593e;
  --teal: #2c7c72;
  --shadow: 6px 6px 0 #27241f;
  --radius: 6px;
  --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;
}

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

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

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

button,
input {
  font: inherit;
}

.container {
  width: min(calc(100% - 32px), var(--container));
  margin-inline: auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 3px solid var(--line);
  background: rgba(252, 252, 247, 0.96);
  transition: box-shadow 180ms ease;
}

.site-header.is-scrolled {
  box-shadow: 0 4px 0 rgba(39, 36, 31, 0.12);
}

.nav-wrap {
  display: flex;
  min-height: 74px;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}

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

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

.site-nav {
  display: flex;
  align-items: center;
  gap: 6px;
}

.site-nav a {
  padding: 8px 13px;
  border-bottom: 3px solid transparent;
  font-weight: 700;
}

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

.download-btn {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  padding: 10px 22px;
  border: 3px solid var(--line);
  border-radius: var(--radius);
  background: var(--yellow);
  box-shadow: 4px 4px 0 var(--line);
  color: var(--ink);
  font-weight: 900;
  transition: transform 150ms ease, box-shadow 150ms ease;
}

.download-btn:hover,
.download-btn:focus-visible {
  box-shadow: 2px 2px 0 var(--line);
  transform: translate(2px, 2px);
}

.download-btn.dark {
  background: var(--ink);
  box-shadow: 4px 4px 0 var(--yellow);
  color: #ffffff;
}

.menu-toggle {
  display: none;
  width: 46px;
  height: 46px;
  padding: 10px;
  border: 3px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  cursor: pointer;
}

.menu-toggle span {
  display: block;
  height: 3px;
  margin: 4px 0;
  background: var(--ink);
}

.hero {
  overflow: hidden;
  border-bottom: 3px solid var(--line);
  background: var(--surface);
}

.hero-grid {
  display: grid;
  min-height: 640px;
  grid-template-columns: minmax(0, 1.05fr) minmax(380px, 0.95fr);
  align-items: center;
  gap: 60px;
  padding-block: 70px;
}

.eyebrow {
  display: inline-block;
  margin: 0 0 20px;
  padding: 5px 10px;
  border: 2px solid var(--line);
  background: var(--yellow-soft);
  font-size: 14px;
  font-weight: 900;
}

h1,
h2,
h3 {
  margin-top: 0;
  line-height: 1.22;
  letter-spacing: 0;
}

h1 {
  max-width: 680px;
  margin-bottom: 20px;
  font-size: clamp(42px, 6vw, 76px);
  font-weight: 950;
}

h2 {
  margin-bottom: 34px;
  font-size: clamp(30px, 4vw, 46px);
}

h3 {
  margin-bottom: 10px;
  font-size: 21px;
}

.hero-copy {
  max-width: 620px;
  margin: 0 0 28px;
  color: var(--muted);
  font-size: 19px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 18px;
}

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

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
}

.hero-tags li {
  padding: 5px 10px;
  border: 2px solid var(--line);
  background: var(--surface);
  font-size: 14px;
  font-weight: 700;
}

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

.phone-panel {
  position: absolute;
  width: min(260px, 60%);
  padding: 10px;
  border: 3px solid var(--line);
  border-radius: 28px;
  background: var(--ink);
  box-shadow: 10px 10px 0 var(--yellow);
}

.phone-panel img {
  width: 100%;
  max-width: 400px;
  height: auto;
  border-radius: 18px;
}

.phone-panel:first-child {
  top: 8px;
  left: 5%;
  z-index: 2;
  transform: rotate(-3deg);
}

.phone-panel.second {
  right: 2%;
  bottom: 0;
  z-index: 1;
  transform: rotate(4deg);
}

.speech-note {
  position: absolute;
  top: 22px;
  right: 0;
  z-index: 3;
  max-width: 170px;
  padding: 12px 15px;
  border: 3px solid var(--line);
  background: var(--surface);
  box-shadow: 4px 4px 0 var(--red);
  font-weight: 900;
  line-height: 1.4;
}

.section {
  padding-block: 86px;
}

.section.alt {
  border-block: 3px solid var(--line);
  background: var(--yellow-soft);
}

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

.section-head .text-link {
  margin-bottom: 42px;
}

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

.feature-card {
  min-height: 240px;
  padding: 25px;
  border: 3px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.feature-card:nth-child(2) {
  background: #e9f7f4;
}

.feature-card:nth-child(3) {
  background: #fff1ec;
}

.feature-number {
  display: grid;
  width: 44px;
  height: 44px;
  margin-bottom: 24px;
  place-items: center;
  border: 2px solid var(--line);
  border-radius: 50%;
  background: var(--yellow);
  font-weight: 950;
}

.feature-card p {
  margin: 0;
  color: var(--muted);
}

.preview-track {
  display: grid;
  grid-template-columns: repeat(5, minmax(200px, 1fr));
  gap: 18px;
  overflow-x: auto;
  padding: 10px 8px 24px 2px;
  scroll-snap-type: x mandatory;
}

.preview-item {
  min-width: 210px;
  scroll-snap-align: start;
}

.preview-item img {
  width: 100%;
  max-width: 400px;
  height: auto;
  border: 3px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 6px 6px 0 var(--ink);
}

.preview-item figcaption {
  margin-top: 15px;
  font-weight: 800;
}

.route-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 26px;
}

.route-card {
  position: relative;
  min-height: 310px;
  padding: 32px;
  overflow: hidden;
  border: 3px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.route-card::after {
  position: absolute;
  right: -35px;
  bottom: -45px;
  width: 160px;
  height: 160px;
  border: 18px solid var(--yellow);
  border-radius: 50%;
  content: "";
}

.route-card.red::after {
  border-color: var(--red);
}

.route-card ul {
  margin: 20px 0 28px;
  padding-left: 20px;
}

.route-card .text-link {
  position: relative;
  z-index: 1;
}

.proof-band {
  border-block: 3px solid var(--line);
  background: var(--teal);
  color: #ffffff;
}

.proof-grid {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: 42px;
  align-items: center;
  padding-block: 70px;
}

.proof-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
}

.stat {
  padding: 18px;
  border: 2px solid #ffffff;
}

.stat strong {
  display: block;
  font-size: 29px;
}

.quote-list {
  display: grid;
  gap: 16px;
}

blockquote {
  margin: 0;
  padding: 20px 24px;
  border: 3px solid var(--line);
  background: var(--surface);
  box-shadow: 5px 5px 0 var(--yellow);
  color: var(--ink);
}

blockquote footer {
  margin-top: 8px;
  color: var(--muted);
  font-size: 14px;
}

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

.faq-item {
  border: 3px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.faq-question {
  display: flex;
  width: 100%;
  min-height: 62px;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 16px 20px;
  border: 0;
  background: transparent;
  color: var(--ink);
  cursor: pointer;
  text-align: left;
  font-weight: 900;
}

.faq-question::after {
  flex: 0 0 auto;
  font-size: 25px;
  content: "+";
}

.faq-item.open .faq-question::after {
  content: "−";
}

.faq-answer {
  display: none;
  padding: 0 20px 18px;
  color: var(--muted);
}

.faq-answer p {
  margin: 0;
}

.faq-item.open .faq-answer {
  display: block;
}

.bottom-cta {
  padding-block: 70px;
  border-top: 3px solid var(--line);
  background: var(--yellow);
}

.cta-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 30px;
}

.cta-inner h2 {
  margin-bottom: 8px;
}

.cta-inner p {
  margin: 0;
  font-weight: 700;
}

.site-footer {
  padding-block: 40px;
  background: var(--ink);
  color: #ffffff;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 30px;
}

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

.disclaimer {
  grid-column: 1 / -1;
  max-width: 900px;
  margin: 0;
  color: #cbc6bd;
  font-size: 14px;
}

.copyright {
  grid-column: 1 / -1;
  margin: 0;
  color: #9d978d;
  font-size: 13px;
}

.page-hero {
  padding-block: 70px;
  border-bottom: 3px solid var(--line);
  background: var(--surface);
}

.page-hero h1 {
  max-width: 900px;
  font-size: clamp(38px, 5vw, 64px);
}

.page-lead {
  max-width: 800px;
  margin: 0;
  color: var(--muted);
  font-size: 19px;
}

.content-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 50px;
  align-items: start;
}

.article-content section {
  margin-bottom: 68px;
}

.article-content h2 {
  margin-bottom: 26px;
  font-size: 34px;
}

.article-content h3 {
  margin-top: 28px;
}

.article-content p {
  color: #4f4b45;
}

.article-content a:not(.download-btn) {
  border-bottom: 2px solid var(--red);
  font-weight: 700;
}

.step-list {
  display: grid;
  gap: 18px;
  padding: 0;
  list-style: none;
  counter-reset: guide-step;
}

.step-list li {
  position: relative;
  min-height: 116px;
  padding: 23px 24px 23px 92px;
  border: 3px solid var(--line);
  background: var(--surface);
  box-shadow: 5px 5px 0 var(--ink);
  counter-increment: guide-step;
}

.step-list li::before {
  position: absolute;
  top: 24px;
  left: 24px;
  display: grid;
  width: 48px;
  height: 48px;
  place-items: center;
  border: 2px solid var(--line);
  border-radius: 50%;
  background: var(--yellow);
  content: counter(guide-step, decimal-leading-zero);
  font-weight: 950;
}

.step-list h3,
.step-list p {
  margin: 0;
}

.step-list p {
  margin-top: 6px;
}

.tip-box {
  padding: 22px 24px;
  border: 3px solid var(--line);
  border-left: 12px solid var(--teal);
  background: #e9f7f4;
}

.tip-box strong {
  display: block;
  margin-bottom: 5px;
}

.guide-figure {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.guide-figure figure {
  margin: 0;
}

.guide-figure img {
  width: 100%;
  max-width: 400px;
  height: auto;
  border: 3px solid var(--line);
  border-radius: var(--radius);
}

.guide-figure figcaption {
  margin-top: 10px;
  color: var(--muted);
  font-size: 14px;
}

.side-nav {
  position: sticky;
  top: 100px;
  padding: 22px;
  border: 3px solid var(--line);
  background: var(--yellow-soft);
  box-shadow: 5px 5px 0 var(--ink);
}

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

.side-nav a {
  display: block;
  padding: 7px 0;
  border-bottom: 1px solid rgba(39, 36, 31, 0.25);
}

.side-nav .download-btn {
  margin-top: 18px;
  border-bottom: 3px solid var(--line);
}

.function-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.function-item {
  padding: 24px;
  border: 3px solid var(--line);
  background: var(--surface);
}

.function-item:nth-child(3n + 2) {
  background: #e9f7f4;
}

.function-item:nth-child(3n + 3) {
  background: #fff1ec;
}

.function-item p {
  margin: 0;
}

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

.trouble-table th,
.trouble-table td {
  padding: 15px;
  border: 2px solid var(--line);
  text-align: left;
  vertical-align: top;
}

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

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

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

@media (max-width: 960px) {
  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .hero-grid {
    min-height: auto;
    grid-template-columns: 1fr;
  }

  .hero-visual {
    width: min(100%, 600px);
    margin-inline: auto;
  }

  .proof-grid,
  .content-grid {
    grid-template-columns: 1fr;
  }

  .side-nav {
    position: static;
    order: -1;
  }
}

@media (max-width: 760px) {
  body {
    font-size: 15px;
  }

  .nav-wrap {
    min-height: 66px;
  }

  .menu-toggle {
    display: block;
  }

  .site-nav {
    position: absolute;
    top: calc(100% + 3px);
    right: 16px;
    left: 16px;
    display: none;
    padding: 12px;
    border: 3px solid var(--line);
    background: var(--surface);
    box-shadow: var(--shadow);
  }

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

  .site-nav .download-btn {
    margin-top: 6px;
  }

  .hero-grid {
    gap: 38px;
    padding-block: 46px;
  }

  h1 {
    font-size: 43px;
  }

  .hero-visual {
    min-height: 430px;
  }

  .phone-panel {
    width: 57%;
  }

  .speech-note {
    max-width: 135px;
    font-size: 13px;
  }

  .section {
    padding-block: 62px;
  }

  .feature-grid,
  .route-grid,
  .function-list,
  .guide-figure {
    grid-template-columns: 1fr;
  }

  .section-head,
  .cta-inner {
    align-items: flex-start;
    flex-direction: column;
  }

  .section-head .text-link {
    margin-top: -24px;
    margin-bottom: 28px;
  }

  .proof-stats {
    grid-template-columns: 1fr;
  }

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

  .footer-links,
  .disclaimer,
  .copyright {
    grid-column: 1;
  }

  .trouble-table,
  .trouble-table tbody,
  .trouble-table tr,
  .trouble-table td {
    display: block;
  }

  .trouble-table thead {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip: rect(0 0 0 0);
  }

  .trouble-table td:first-child {
    border-bottom: 0;
    background: var(--yellow-soft);
    font-weight: 900;
  }

  .trouble-table tr + tr td:first-child {
    border-top: 0;
  }
}

@media (max-width: 430px) {
  .container {
    width: min(calc(100% - 22px), var(--container));
  }

  .brand {
    font-size: 18px;
  }

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

  h1 {
    font-size: 37px;
  }

  h2 {
    font-size: 30px;
  }

  .hero-copy,
  .page-lead {
    font-size: 17px;
  }

  .hero-visual {
    min-height: 360px;
  }

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

  .step-list li {
    padding: 82px 20px 20px;
  }
}

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

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

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