:root {
  --ink: #171717;
  --paper: #f7f4ec;
  --paper-strong: #fffdf7;
  --vermilion: #d94732;
  --teal: #167c80;
  --gold: #b68a37;
  --muted: #66625a;
  --line: #d8d2c5;
  --shadow: 0 18px 50px rgba(23, 23, 23, 0.14);
  --max: 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;
  line-height: 1.75;
}

body::before {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  content: "";
  opacity: 0.32;
  background-image:
    linear-gradient(rgba(23, 23, 23, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(23, 23, 23, 0.025) 1px, transparent 1px);
  background-size: 28px 28px;
}

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

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

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

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(247, 244, 236, 0.94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(16px);
}

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

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  flex: 0 0 auto;
  font-size: 19px;
  font-weight: 800;
}

.brand img {
  width: 42px;
  height: 42px;
  border-radius: 6px;
  box-shadow: 0 5px 14px rgba(23, 23, 23, 0.16);
}

.site-nav {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 4px;
}

.site-nav a {
  padding: 10px 14px;
  border-bottom: 2px solid transparent;
  font-size: 15px;
  font-weight: 700;
}

.nav-download,
.download-button {
  display: inline-flex;
  min-height: 46px;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 11px 22px;
  color: #fff;
  background: var(--vermilion);
  border: 2px solid var(--ink);
  border-radius: 4px;
  box-shadow: 5px 5px 0 var(--ink);
  font-weight: 800;
  transition: transform 160ms ease, box-shadow 160ms ease;
}

.nav-download:hover,
.download-button:hover {
  transform: translate(2px, 2px);
  box-shadow: 3px 3px 0 var(--ink);
}

.download-button::after,
.nav-download::after {
  content: "\2193";
  font-size: 18px;
  line-height: 1;
}

.menu-button {
  display: none;
  width: 44px;
  height: 44px;
  margin-left: auto;
  padding: 0;
  align-items: center;
  justify-content: center;
  color: var(--ink);
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 4px;
  font-size: 0;
  cursor: pointer;
}

.menu-button span,
.menu-button::before,
.menu-button::after {
  width: 20px;
  height: 2px;
  display: block;
  content: "";
  background: currentColor;
}

.menu-button span {
  margin: 5px 0;
}

.hero {
  min-height: 680px;
  padding: 74px 0 56px;
  overflow: hidden;
  border-bottom: 1px solid var(--line);
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(390px, 0.95fr);
  align-items: center;
  gap: 64px;
}

.eyebrow,
.section-kicker {
  margin: 0 0 12px;
  color: var(--teal);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: 0;
}

.eyebrow::before,
.section-kicker::before {
  display: inline-block;
  width: 24px;
  height: 4px;
  margin-right: 9px;
  vertical-align: 3px;
  content: "";
  background: var(--gold);
}

h1,
h2,
h3,
p {
  overflow-wrap: anywhere;
}

h1,
h2,
h3 {
  margin-top: 0;
  line-height: 1.2;
}

h1 {
  max-width: 620px;
  margin-bottom: 22px;
  font-size: clamp(44px, 5vw, 68px);
  letter-spacing: 0;
}

h2 {
  margin-bottom: 30px;
  font-size: clamp(30px, 4vw, 48px);
  letter-spacing: 0;
}

h3 {
  margin-bottom: 12px;
  font-size: 21px;
  letter-spacing: 0;
}

.hero-copy {
  max-width: 650px;
  margin: 0 0 28px;
  color: #4c4943;
  font-size: 19px;
}

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

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

.version-note strong {
  display: block;
  color: var(--ink);
  font-size: 15px;
}

.hero-proof {
  display: flex;
  gap: 12px;
  margin: 34px 0 0;
  padding: 0;
  list-style: none;
  flex-wrap: wrap;
}

.hero-proof li {
  padding: 6px 12px;
  background: var(--paper-strong);
  border: 1px solid var(--line);
  border-radius: 999px;
  color: #555149;
  font-size: 13px;
  font-weight: 700;
}

.phone-stage {
  position: relative;
  min-height: 535px;
}

.phone-stage::before {
  position: absolute;
  top: 8%;
  right: 0;
  width: 78%;
  height: 72%;
  content: "";
  background: var(--teal);
  clip-path: polygon(12% 0, 100% 8%, 88% 100%, 0 90%);
}

.phone-stage::after {
  position: absolute;
  right: 2%;
  bottom: 6%;
  width: 70%;
  height: 31%;
  content: "";
  background: repeating-linear-gradient(135deg, transparent 0 12px, rgba(23, 23, 23, 0.13) 12px 14px);
}

.hero-phone {
  position: absolute;
  z-index: 2;
  width: min(250px, 58%);
  max-width: 400px;
  height: auto;
  border: 8px solid var(--ink);
  border-radius: 24px;
  box-shadow: var(--shadow);
}

.hero-phone:first-child {
  top: 0;
  left: 2%;
  transform: rotate(-4deg);
}

.hero-phone:last-child {
  right: 2%;
  bottom: 0;
  transform: rotate(4deg);
}

.data-strip {
  color: #fff;
  background: var(--ink);
}

.data-grid {
  min-height: 122px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  align-items: center;
}

.data-item {
  padding: 22px 28px;
  border-left: 1px solid #3c3c3c;
}

.data-item:last-child {
  border-right: 1px solid #3c3c3c;
}

.data-item strong {
  display: block;
  color: #f4cf75;
  font-size: 24px;
}

.data-item span {
  color: #b8b5ae;
  font-size: 13px;
}

.section {
  padding: 96px 0;
}

.section-rule {
  border-bottom: 1px solid var(--line);
}

.section-heading {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(300px, 1.2fr);
  align-items: end;
  gap: 50px;
  margin-bottom: 48px;
}

.section-heading h2 {
  margin-bottom: 0;
}

.section-heading > div:last-child {
  color: var(--muted);
  font-size: 16px;
}

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

.feature-item {
  min-height: 230px;
  padding: 34px;
  background: rgba(255, 253, 247, 0.7);
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.feature-number {
  display: inline-flex;
  width: 36px;
  height: 36px;
  margin-bottom: 32px;
  align-items: center;
  justify-content: center;
  color: #fff;
  background: var(--teal);
  font-size: 13px;
  font-weight: 900;
}

.feature-item:nth-child(2) .feature-number,
.feature-item:nth-child(3) .feature-number {
  background: var(--vermilion);
}

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

.showcase {
  color: #f8f4e9;
  background: #20201f;
}

.showcase h2,
.showcase h3 {
  color: #fff;
}

.showcase .section-kicker {
  color: #7ed5cf;
}

.showcase-grid {
  display: grid;
  grid-template-columns: minmax(300px, 0.75fr) minmax(0, 1.25fr);
  gap: 70px;
  align-items: center;
}

.preview-copy p {
  color: #c4c0b8;
}

.preview-tabs {
  display: grid;
  gap: 4px;
  margin-top: 30px;
}

.preview-tab {
  width: 100%;
  padding: 16px 18px;
  color: #cfcbc1;
  background: transparent;
  border: 1px solid #454542;
  border-radius: 3px;
  text-align: left;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
}

.preview-tab[aria-selected="true"] {
  color: var(--ink);
  background: #f4cf75;
  border-color: #f4cf75;
}

.preview-frame {
  position: relative;
  min-height: 610px;
  display: grid;
  place-items: center;
  overflow: hidden;
}

.preview-frame::before {
  position: absolute;
  inset: 7% 0;
  content: "";
  background: var(--vermilion);
  clip-path: polygon(0 9%, 94% 0, 100% 89%, 8% 100%);
}

.app-preview {
  position: relative;
  z-index: 2;
  width: min(100%, 330px);
  max-width: 400px;
  height: auto;
  border: 8px solid #0f0f0f;
  border-radius: 26px;
  box-shadow: 0 30px 70px rgba(0, 0, 0, 0.38);
}

.deep-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 20px;
}

.deep-link {
  min-height: 280px;
  padding: 38px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  background: var(--paper-strong);
  border: 1px solid var(--line);
  border-top: 5px solid var(--vermilion);
}

.deep-link:last-child {
  border-top-color: var(--teal);
}

.deep-link p {
  color: var(--muted);
}

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

.text-link::after {
  content: "\2192";
  color: var(--vermilion);
  font-size: 20px;
}

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

.quote {
  margin: 0;
  padding: 34px 30px;
  background: rgba(255, 253, 247, 0.7);
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.quote:first-child {
  border-left: 1px solid var(--line);
}

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

.quote footer {
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
}

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

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

.faq-question {
  width: 100%;
  min-height: 72px;
  padding: 18px 48px 18px 0;
  position: relative;
  color: var(--ink);
  background: transparent;
  border: 0;
  text-align: left;
  font: inherit;
  font-size: 17px;
  font-weight: 800;
  cursor: pointer;
}

.faq-question::after {
  position: absolute;
  top: 50%;
  right: 10px;
  content: "+";
  transform: translateY(-50%);
  color: var(--vermilion);
  font-size: 28px;
}

.faq-question[aria-expanded="true"]::after {
  content: "\2212";
}

.faq-answer {
  display: none;
  max-width: 920px;
  padding: 0 52px 24px 0;
  color: var(--muted);
}

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

.download-band {
  padding: 66px 0;
  color: #fff;
  background: var(--teal);
}

.download-band .shell {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 40px;
}

.download-band h2 {
  margin-bottom: 8px;
  font-size: 36px;
}

.download-band p {
  margin: 0;
  color: #d8efed;
}

.download-band .download-button {
  color: var(--ink);
  background: #f4cf75;
}

.site-footer {
  padding: 54px 0 30px;
  color: #d8d4cb;
  background: #171717;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr 1fr;
  gap: 50px;
  padding-bottom: 34px;
}

.footer-brand {
  color: #fff;
}

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

.footer-copy,
.disclaimer,
.copyright {
  color: #96938c;
  font-size: 13px;
}

.footer-nav {
  display: grid;
  align-content: start;
  gap: 8px;
}

.footer-nav a:hover {
  color: #f4cf75;
}

.footer-note strong {
  color: #fff;
}

.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid #353535;
}

.disclaimer {
  margin: 0 0 10px;
}

.copyright {
  margin: 0;
}

.sub-hero {
  padding: 82px 0 64px;
  border-bottom: 1px solid var(--line);
}

.sub-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 70px;
  align-items: end;
}

.sub-hero h1 {
  margin-bottom: 18px;
  font-size: clamp(40px, 6vw, 68px);
}

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

.sub-index {
  padding: 26px;
  color: #fff;
  background: var(--ink);
  border-top: 5px solid var(--gold);
}

.sub-index strong {
  display: block;
  margin-bottom: 10px;
  color: #f4cf75;
}

.sub-index span {
  display: block;
  color: #bbb8b0;
  font-size: 14px;
}

.guide-layout,
.article-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 290px;
  gap: 70px;
  align-items: start;
}

.content-flow > section {
  padding: 0 0 64px;
  margin-bottom: 64px;
  border-bottom: 1px solid var(--line);
}

.content-flow > section:last-child {
  margin-bottom: 0;
}

.content-flow h2 {
  font-size: 34px;
}

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

.content-flow p,
.content-flow li {
  color: #514e47;
}

.step-list {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: steps;
}

.step-list li {
  position: relative;
  min-height: 118px;
  padding: 26px 24px 26px 92px;
  counter-increment: steps;
  border-top: 1px solid var(--line);
}

.step-list li:last-child {
  border-bottom: 1px solid var(--line);
}

.step-list li::before {
  position: absolute;
  top: 24px;
  left: 18px;
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  content: counter(steps, decimal-leading-zero);
  color: #fff;
  background: var(--vermilion);
  font-weight: 900;
}

.step-list strong {
  display: block;
  color: var(--ink);
  font-size: 18px;
}

.notice {
  padding: 24px 28px;
  background: #fff6da;
  border-left: 5px solid var(--gold);
}

.notice strong {
  color: var(--ink);
}

.side-nav {
  position: sticky;
  top: 104px;
  padding: 26px;
  background: var(--paper-strong);
  border: 1px solid var(--line);
}

.side-nav strong {
  display: block;
  margin-bottom: 14px;
}

.side-nav a {
  display: block;
  padding: 8px 0;
  color: var(--muted);
  border-bottom: 1px solid #ebe6da;
  font-size: 14px;
}

.side-nav a:hover {
  color: var(--vermilion);
}

.feature-detail {
  display: grid;
  grid-template-columns: 170px 1fr;
  gap: 34px;
  padding: 32px 0;
  border-top: 1px solid var(--line);
}

.feature-detail:last-child {
  border-bottom: 1px solid var(--line);
}

.feature-detail h3 {
  margin: 0;
  color: var(--teal);
}

.feature-detail p {
  margin: 0;
}

.check-list {
  padding-left: 22px;
}

.check-list li {
  margin-bottom: 10px;
}

@media (max-width: 920px) {
  .menu-button {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: 76px;
    left: 0;
    width: 100%;
    padding: 16px 20px 22px;
    display: none;
    align-items: stretch;
    background: var(--paper-strong);
    border-bottom: 1px solid var(--line);
    box-shadow: 0 16px 28px rgba(23, 23, 23, 0.12);
  }

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

  .site-nav a {
    border-bottom: 1px solid var(--line);
  }

  .nav-download {
    margin-top: 8px;
  }

  .hero-grid,
  .showcase-grid,
  .sub-hero-grid,
  .guide-layout,
  .article-layout {
    grid-template-columns: 1fr;
  }

  .hero {
    padding-top: 54px;
  }

  .hero-grid {
    gap: 44px;
  }

  .phone-stage {
    width: min(100%, 620px);
    margin-inline: auto;
  }

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

  .data-item:nth-child(3) {
    border-top: 1px solid #3c3c3c;
  }

  .data-item:nth-child(4) {
    border-top: 1px solid #3c3c3c;
  }

  .section-heading,
  .deep-grid {
    grid-template-columns: 1fr;
  }

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

  .quote {
    border-left: 1px solid var(--line);
  }

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

  .footer-note {
    grid-column: 1 / -1;
  }

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

@media (max-width: 620px) {
  .shell {
    width: min(calc(100% - 28px), var(--max));
  }

  .brand {
    font-size: 17px;
  }

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

  .hero {
    min-height: auto;
    padding-top: 42px;
  }

  h1 {
    font-size: 42px;
  }

  h2 {
    font-size: 32px;
  }

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

  .phone-stage {
    min-height: 460px;
  }

  .hero-phone {
    width: 210px;
  }

  .hero-phone:first-child {
    left: 0;
  }

  .hero-phone:last-child {
    right: 0;
  }

  .data-grid,
  .feature-ledger,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .data-item,
  .data-item:last-child {
    border-right: 0;
    border-left: 0;
    border-top: 1px solid #3c3c3c;
  }

  .section {
    padding: 70px 0;
  }

  .section-heading {
    gap: 16px;
  }

  .feature-item,
  .deep-link {
    min-height: auto;
    padding: 28px 24px;
  }

  .preview-frame {
    min-height: 520px;
  }

  .app-preview {
    width: min(88%, 290px);
  }

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

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

  .footer-note {
    grid-column: auto;
  }

  .sub-hero {
    padding-top: 54px;
  }

  .sub-hero h1 {
    font-size: 36px;
  }

  .feature-detail {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .step-list li {
    padding-left: 78px;
  }
}

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

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