:root {
  --ink: #172029;
  --muted: #667078;
  --paper: #f5f7f6;
  --white: #ffffff;
  --teal: #087f72;
  --teal-dark: #075e56;
  --coral: #ff5d5d;
  --yellow: #ffd45c;
  --line: #dce3e1;
  --shadow: 8px 8px 0 rgba(23, 32, 41, 0.12);
  --radius: 6px;
  --container: 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.menu-open {
  overflow: hidden;
}

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% - 40px), var(--container));
  margin: 0 auto;
}

.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 200;
  padding: 8px 14px;
  color: var(--white);
  background: var(--ink);
  transform: translateY(-160%);
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 2px solid var(--ink);
  background: rgba(255, 255, 255, 0.96);
}

.nav-wrap {
  display: flex;
  min-height: 72px;
  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;
  color: var(--ink);
}

.brand img {
  width: 42px;
  height: 42px;
  border: 2px solid var(--ink);
  border-radius: 4px;
}

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

.nav-link {
  padding: 10px 14px;
  color: #404a52;
  font-weight: 700;
}

.nav-link:hover,
.nav-link[aria-current="page"] {
  color: var(--teal-dark);
  box-shadow: inset 0 -3px 0 var(--teal);
}

.button {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 22px;
  border: 2px solid var(--ink);
  border-radius: 4px;
  color: var(--white);
  background: var(--teal);
  box-shadow: 4px 4px 0 var(--ink);
  font-weight: 900;
  line-height: 1.2;
  cursor: pointer;
  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(--ink);
  transform: translate(2px, 2px);
}

.button:focus-visible,
.nav-link:focus-visible,
.menu-toggle:focus-visible,
.text-link:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--yellow);
  outline-offset: 3px;
}

.button-coral {
  background: var(--coral);
}

.button-coral:hover {
  background: #dd4545;
}

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

.button-light:hover {
  color: var(--ink);
  background: var(--yellow);
}

.nav-download {
  min-height: 42px;
  padding: 9px 16px;
  box-shadow: 3px 3px 0 var(--ink);
}

.menu-toggle {
  display: none;
  width: 44px;
  height: 44px;
  padding: 10px;
  border: 2px solid var(--ink);
  border-radius: 4px;
  background: var(--white);
  cursor: pointer;
}

.menu-toggle span {
  display: block;
  height: 2px;
  margin: 5px 0;
  background: var(--ink);
}

.eyebrow {
  display: inline-block;
  margin: 0 0 16px;
  padding: 5px 10px;
  border: 2px solid var(--ink);
  background: var(--yellow);
  color: var(--ink);
  font-size: 13px;
  font-weight: 900;
}

.hero {
  min-height: 620px;
  overflow: hidden;
  border-bottom: 2px solid var(--ink);
  background: #eaf2f0;
}

.hero-grid {
  display: grid;
  min-height: 620px;
  grid-template-columns: minmax(0, 1fr) minmax(390px, 0.88fr);
  align-items: center;
  gap: 64px;
  padding: 58px 0 48px;
}

.hero-copy h1,
.page-hero h1 {
  margin: 0;
  max-width: 720px;
  font-size: 56px;
  line-height: 1.12;
  letter-spacing: 0;
}

.hero-copy > p {
  max-width: 680px;
  margin: 24px 0 0;
  color: #3e494f;
  font-size: 18px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 30px;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 24px;
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
}

.hero-meta li {
  display: grid;
  gap: 1px;
}

.hero-meta strong {
  font-size: 19px;
}

.hero-meta span {
  color: var(--muted);
  font-size: 13px;
}

.phone-stage {
  position: relative;
  min-height: 500px;
}

.phone-frame {
  position: absolute;
  width: min(250px, 62%);
  overflow: hidden;
  border: 4px solid var(--ink);
  border-radius: 8px;
  background: var(--white);
  box-shadow: var(--shadow);
}

.phone-frame img {
  width: 100%;
  max-width: 400px;
  height: auto;
}

.phone-main {
  right: 14px;
  bottom: 0;
  z-index: 2;
}

.phone-secondary {
  top: 0;
  left: 12px;
  z-index: 1;
  transform: rotate(-3deg);
}

.stage-note {
  position: absolute;
  right: 156px;
  bottom: 70px;
  z-index: 3;
  width: 156px;
  padding: 12px 14px;
  border: 2px solid var(--ink);
  background: var(--yellow);
  box-shadow: 4px 4px 0 var(--ink);
  font-size: 13px;
  font-weight: 900;
  line-height: 1.45;
  transform: rotate(2deg);
}

.section {
  padding: 82px 0;
}

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

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

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

.section-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 38px;
}

.section-heading h2 {
  margin: 0;
  max-width: 760px;
  font-size: 38px;
  line-height: 1.2;
  letter-spacing: 0;
}

.section-number {
  color: var(--coral);
  font-size: 15px;
  font-weight: 900;
}

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

.feature-card {
  min-height: 250px;
  padding: 26px;
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: 5px 5px 0 rgba(23, 32, 41, 0.14);
}

.feature-card:nth-child(2) {
  border-top: 8px solid var(--coral);
}

.feature-card:nth-child(3) {
  border-top: 8px solid var(--teal);
}

.feature-card:nth-child(4) {
  border-top: 8px solid var(--yellow);
}

.feature-index {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  border: 2px solid var(--ink);
  border-radius: 50%;
  background: var(--yellow);
  font-weight: 900;
}

.feature-card h3,
.path-card h3,
.review-card h3,
.content-block h2,
.content-block h3,
.step-copy h2,
.step-copy h3 {
  letter-spacing: 0;
}

.feature-card h3 {
  margin: 20px 0 8px;
  font-size: 21px;
}

.feature-card p {
  margin: 0;
  color: #526069;
  font-size: 15px;
}

.preview-layout {
  display: grid;
  grid-template-columns: 0.72fr 1.28fr;
  gap: 70px;
  align-items: center;
}

.preview-copy h2 {
  margin: 0 0 20px;
  font-size: 38px;
  line-height: 1.2;
}

.preview-copy p {
  color: #cfd8da;
}

.fact-list {
  display: grid;
  gap: 12px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

.fact-list li {
  padding-left: 18px;
  border-left: 4px solid var(--yellow);
}

.preview-strip {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  align-items: end;
}

.preview-item {
  margin: 0;
}

.preview-item:nth-child(2) {
  transform: translateY(-28px);
}

.preview-item img {
  width: 100%;
  max-width: 400px;
  height: auto;
  border: 3px solid var(--white);
  border-radius: 6px;
  background: var(--white);
}

.preview-item figcaption {
  margin-top: 10px;
  color: #d5dddf;
  font-size: 13px;
}

.path-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 22px;
}

.path-card {
  position: relative;
  min-height: 280px;
  padding: 32px;
  overflow: hidden;
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background: var(--white);
}

.path-card::after {
  content: attr(data-mark);
  position: absolute;
  right: 18px;
  bottom: -34px;
  color: #e8edeb;
  font-size: 128px;
  font-weight: 900;
  line-height: 1;
}

.path-card h3,
.path-card p,
.path-card a {
  position: relative;
  z-index: 1;
}

.path-card h3 {
  margin: 16px 0 10px;
  font-size: 26px;
}

.path-card p {
  max-width: 540px;
  color: #526069;
}

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

.text-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 14px;
  color: var(--teal-dark);
  font-weight: 900;
}

.text-link::after {
  content: "\2192";
}

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

.review-card {
  padding: 26px;
  border: 2px solid rgba(255, 255, 255, 0.75);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.07);
}

.review-card blockquote {
  margin: 0;
  font-size: 17px;
}

.review-card cite {
  display: block;
  margin-top: 18px;
  color: #bfe2dc;
  font-size: 13px;
  font-style: normal;
}

.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 54px 18px 20px;
  font-weight: 900;
  cursor: pointer;
  list-style: none;
}

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

.faq-list summary::after {
  content: "+";
  position: absolute;
  top: 14px;
  right: 18px;
  color: var(--teal);
  font-size: 26px;
}

.faq-list details[open] summary::after {
  content: "\2212";
}

.faq-answer {
  padding: 0 20px 20px;
  color: #4c5961;
}

.faq-answer p {
  margin: 0;
}

.download-band {
  padding: 54px 0;
  border-top: 2px solid var(--ink);
  border-bottom: 2px solid var(--ink);
  background: var(--yellow);
}

.download-band-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
}

.download-band h2 {
  margin: 0 0 8px;
  font-size: 32px;
  line-height: 1.2;
}

.download-band p {
  margin: 0;
  color: #4d5254;
}

.page-hero {
  padding: 72px 0 64px;
  border-bottom: 2px solid var(--ink);
  background: #eaf2f0;
}

.page-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 310px;
  align-items: end;
  gap: 60px;
}

.page-hero p {
  max-width: 760px;
  margin: 24px 0 0;
  color: #3f4d54;
  font-size: 18px;
}

.page-kicker {
  padding: 24px;
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background: var(--coral);
  box-shadow: var(--shadow);
  color: var(--white);
  transform: rotate(1deg);
}

.page-kicker strong {
  display: block;
  font-size: 38px;
  line-height: 1.1;
}

.page-kicker span {
  display: block;
  margin-top: 8px;
}

.article-shell {
  display: grid;
  grid-template-columns: 230px minmax(0, 1fr);
  gap: 70px;
  align-items: start;
}

.article-nav {
  position: sticky;
  top: 102px;
  padding-left: 16px;
  border-left: 4px solid var(--teal);
}

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

.article-nav a {
  display: block;
  padding: 7px 0;
  color: #59656d;
  font-size: 14px;
}

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

.article-content {
  min-width: 0;
}

.content-block {
  padding: 0 0 56px;
  scroll-margin-top: 100px;
}

.content-block + .content-block {
  padding-top: 56px;
  border-top: 2px solid var(--line);
}

.content-block h2 {
  margin: 0 0 24px;
  font-size: 32px;
  line-height: 1.25;
}

.content-block h3 {
  margin: 28px 0 10px;
  font-size: 21px;
}

.content-block p {
  margin: 0 0 16px;
  color: #46545c;
}

.check-list,
.plain-list {
  display: grid;
  gap: 12px;
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
}

.check-list li,
.plain-list li {
  position: relative;
  padding: 15px 18px 15px 48px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.check-list li::before {
  content: "\2713";
  position: absolute;
  top: 14px;
  left: 17px;
  color: var(--teal);
  font-weight: 900;
}

.plain-list li {
  padding-left: 18px;
}

.step-list {
  display: grid;
  gap: 0;
}

.step {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr);
  gap: 26px;
  padding: 34px 0;
  border-top: 2px solid var(--line);
  scroll-margin-top: 96px;
}

.step:first-child {
  border-top: 0;
  padding-top: 0;
}

.step-number {
  display: grid;
  width: 64px;
  height: 64px;
  place-items: center;
  border: 2px solid var(--ink);
  border-radius: 50%;
  background: var(--yellow);
  box-shadow: 4px 4px 0 var(--ink);
  font-size: 22px;
  font-weight: 900;
}

.step-copy h2 {
  margin: 4px 0 12px;
  font-size: 27px;
  line-height: 1.25;
}

.step-copy p {
  margin: 0 0 12px;
  color: #46545c;
}

.inline-note {
  margin: 22px 0;
  padding: 18px 20px;
  border-left: 6px solid var(--coral);
  background: #fff0ef;
  color: #493c3c;
}

.screenshot-inline {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(180px, 280px);
  gap: 32px;
  align-items: center;
  margin: 28px 0;
}

.screenshot-inline img {
  width: 100%;
  max-width: 400px;
  height: auto;
  border: 3px solid var(--ink);
  border-radius: 6px;
  box-shadow: 6px 6px 0 rgba(23, 32, 41, 0.14);
}

.tip-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-top: 24px;
}

.tip-card {
  padding: 22px;
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background: var(--white);
}

.tip-card h3 {
  margin: 0 0 8px;
  font-size: 19px;
}

.tip-card p {
  margin: 0;
  font-size: 14px;
}

.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 28px;
}

.filter-button {
  padding: 9px 14px;
  border: 2px solid var(--ink);
  border-radius: 4px;
  color: var(--ink);
  background: var(--white);
  font-weight: 800;
  cursor: pointer;
}

.filter-button:hover,
.filter-button.is-active {
  background: var(--yellow);
}

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

.site-footer {
  padding: 48px 0 30px;
  color: #c6ced1;
  background: #10171d;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.7fr 0.7fr;
  gap: 50px;
}

.footer-brand {
  color: var(--white);
}

.footer-grid h2,
.footer-grid h3 {
  margin: 0 0 14px;
  color: var(--white);
  font-size: 17px;
}

.footer-grid p {
  margin: 14px 0 0;
  font-size: 14px;
}

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

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

.disclaimer {
  margin: 36px 0 0;
  padding-top: 22px;
  border-top: 1px solid #344049;
  font-size: 13px;
}

.copyright {
  margin: 8px 0 0;
  color: #818d94;
  font-size: 12px;
}

@media (max-width: 980px) {
  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .hero-grid {
    grid-template-columns: minmax(0, 1fr) 360px;
    gap: 34px;
  }

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

  .article-shell {
    grid-template-columns: 1fr;
    gap: 36px;
  }

  .article-nav {
    position: static;
    display: flex;
    flex-wrap: wrap;
    gap: 8px 18px;
    padding: 14px 0;
    border-top: 2px solid var(--line);
    border-bottom: 2px solid var(--line);
    border-left: 0;
  }

  .article-nav strong {
    width: 100%;
    margin: 0;
  }

  .article-nav a {
    padding: 2px 0;
  }
}

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

  .nav-wrap {
    min-height: 64px;
  }

  .menu-toggle {
    display: block;
  }

  .nav-menu {
    position: fixed;
    top: 64px;
    right: 0;
    bottom: 0;
    left: 0;
    display: none;
    align-content: start;
    padding: 24px 20px;
    border-top: 2px solid var(--ink);
    background: var(--white);
  }

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

  .nav-link {
    padding: 14px 8px;
    border-bottom: 1px solid var(--line);
  }

  .nav-download {
    margin-top: 12px;
  }

  .hero,
  .hero-grid {
    min-height: auto;
  }

  .hero-grid {
    grid-template-columns: 1fr;
    padding-top: 48px;
  }

  .hero-copy h1,
  .page-hero h1 {
    font-size: 40px;
  }

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

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

  .phone-frame {
    width: min(230px, 62%);
  }

  .phone-main {
    right: 2%;
  }

  .phone-secondary {
    left: 2%;
  }

  .stage-note {
    right: 32%;
  }

  .section {
    padding: 62px 0;
  }

  .section-heading {
    align-items: start;
    flex-direction: column;
  }

  .section-heading h2,
  .preview-copy h2 {
    font-size: 31px;
  }

  .path-grid,
  .review-grid,
  .page-hero-grid,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .page-kicker {
    max-width: 320px;
  }

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

  .download-band .button {
    align-self: flex-start;
  }
}

@media (max-width: 540px) {
  .brand {
    font-size: 19px;
  }

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

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

  .hero-copy h1,
  .page-hero h1 {
    font-size: 34px;
  }

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

  .hero-meta {
    gap: 18px;
  }

  .phone-stage {
    min-height: 410px;
  }

  .stage-note {
    right: 24%;
    bottom: 40px;
  }

  .preview-strip {
    grid-template-columns: 1fr;
  }

  .preview-item,
  .preview-item:nth-child(2) {
    max-width: 300px;
    margin: 0 auto;
    transform: none;
  }

  .path-card {
    padding: 24px;
  }

  .step {
    grid-template-columns: 50px minmax(0, 1fr);
    gap: 16px;
  }

  .step-number {
    width: 46px;
    height: 46px;
    font-size: 16px;
  }

  .step-copy h2 {
    font-size: 23px;
  }

  .screenshot-inline {
    grid-template-columns: 1fr;
  }

  .screenshot-inline img {
    width: min(100%, 300px);
  }
}

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

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