:root {
  --ink: #17171b;
  --paper: #f7f7f2;
  --white: #ffffff;
  --cyan: #35d7c7;
  --cyan-dark: #127e76;
  --coral: #ff5e62;
  --yellow: #ffd84d;
  --muted: #686870;
  --line: #d9d9d2;
  --max: 1180px;
  --shadow: 7px 7px 0 var(--ink);
}

* {
  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.nav-open {
  overflow: hidden;
}

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

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

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

.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 100;
  padding: 8px 12px;
  color: var(--white);
  background: var(--ink);
  transform: translateY(-150%);
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 3px solid var(--ink);
  background: rgba(247, 247, 242, 0.96);
}

.nav-shell {
  width: min(calc(100% - 32px), var(--max));
  min-height: 72px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 22px;
  font-weight: 900;
}

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

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

.nav-links > a:not(.download-btn) {
  min-height: 42px;
  padding: 8px 13px;
  border-bottom: 3px solid transparent;
  font-weight: 700;
}

.nav-links > a[aria-current="page"],
.nav-links > a:not(.download-btn):hover {
  border-color: var(--coral);
}

.menu-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border: 2px solid var(--ink);
  background: var(--white);
  font-size: 24px;
  cursor: pointer;
}

.download-btn {
  min-height: 46px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border: 2px solid var(--ink);
  border-radius: 4px;
  color: var(--ink);
  background: var(--cyan);
  box-shadow: 4px 4px 0 var(--ink);
  font-weight: 900;
  cursor: pointer;
  transition: transform 160ms ease, box-shadow 160ms ease;
}

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

.download-btn:focus-visible,
.menu-toggle:focus-visible,
a:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--coral);
  outline-offset: 3px;
}

.container {
  width: min(calc(100% - 32px), var(--max));
  margin: 0 auto;
}

.hero {
  min-height: 660px;
  overflow: hidden;
  border-bottom: 3px solid var(--ink);
  background-color: var(--ink);
  color: var(--white);
}

.hero-grid {
  min-height: 660px;
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(320px, 0.95fr);
  align-items: center;
  gap: 64px;
  padding: 70px 0 56px;
}

.eyebrow,
.section-kicker {
  display: inline-block;
  margin: 0 0 18px;
  padding: 4px 9px;
  border: 2px solid currentColor;
  color: var(--cyan);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: 0;
}

.hero h1 {
  max-width: 680px;
  margin: 0;
  font-size: clamp(46px, 7vw, 88px);
  line-height: 1.05;
  letter-spacing: 0;
}

.hero-lead {
  max-width: 640px;
  margin: 24px 0;
  color: #d8d8dc;
  font-size: 18px;
}

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

.hero-note {
  color: #b6b6be;
  font-size: 14px;
}

.hero-visual {
  position: relative;
  min-height: 500px;
  display: grid;
  place-items: center;
}

.hero-visual::before {
  content: "E";
  position: absolute;
  right: 2%;
  top: -16%;
  color: var(--yellow);
  font-size: 330px;
  font-weight: 900;
  line-height: 1;
  opacity: 0.12;
}

.phone-shot {
  position: relative;
  z-index: 2;
  width: min(74%, 315px);
  max-width: 400px;
  height: auto;
  border: 4px solid var(--white);
  box-shadow: 18px 18px 0 var(--coral);
  transform: rotate(2deg);
}

.hero-stamp {
  position: absolute;
  z-index: 3;
  right: 2%;
  bottom: 12%;
  width: 118px;
  height: 118px;
  display: grid;
  place-items: center;
  border: 3px solid var(--ink);
  border-radius: 50%;
  color: var(--ink);
  background: var(--yellow);
  font-size: 18px;
  font-weight: 900;
  text-align: center;
  transform: rotate(-8deg);
}

.quick-facts {
  border-bottom: 3px solid var(--ink);
  background: var(--cyan);
}

.facts-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
}

.fact {
  padding: 24px;
  border-left: 2px solid var(--ink);
}

.fact:last-child {
  border-right: 2px solid var(--ink);
}

.fact strong,
.fact span {
  display: block;
}

.fact strong {
  font-size: 25px;
  line-height: 1.2;
}

.fact span {
  margin-top: 5px;
  font-size: 13px;
  font-weight: 700;
}

.section {
  padding: 84px 0;
}

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

.section-cyan {
  border-top: 3px solid var(--ink);
  border-bottom: 3px solid var(--ink);
  background: var(--cyan);
}

.section-coral {
  border-top: 3px solid var(--ink);
  border-bottom: 3px solid var(--ink);
  background: var(--coral);
}

.section-heading {
  margin: 0 0 38px;
  font-size: clamp(30px, 4.4vw, 52px);
  line-height: 1.15;
  letter-spacing: 0;
}

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

.feature-card {
  min-height: 250px;
  padding: 26px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--white);
  box-shadow: 6px 6px 0 var(--ink);
}

.feature-card:nth-child(2),
.feature-card:nth-child(5) {
  background: #e9fffb;
}

.feature-card:nth-child(3),
.feature-card:nth-child(6) {
  background: #fff4d1;
}

.feature-index {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border: 2px solid var(--ink);
  background: var(--coral);
  font-weight: 900;
}

.feature-card h3 {
  margin: 20px 0 8px;
  font-size: 22px;
}

.feature-card p {
  margin: 0;
  color: #48484e;
}

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

.shot-toolbar .section-heading {
  margin: 0;
}

.scroll-controls {
  display: flex;
  gap: 8px;
}

.scroll-controls button {
  width: 48px;
  height: 48px;
  border: 2px solid var(--white);
  color: var(--white);
  background: transparent;
  font-size: 26px;
  cursor: pointer;
}

.screenshot-track {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(230px, 285px);
  gap: 26px;
  overflow-x: auto;
  padding: 6px 8px 28px 0;
  scroll-snap-type: x mandatory;
  scrollbar-color: var(--cyan) #33333a;
}

.screenshot-item {
  margin: 0;
  scroll-snap-align: start;
}

.screenshot-item img {
  width: 100%;
  max-width: 400px;
  height: auto;
  aspect-ratio: 9 / 16;
  object-fit: cover;
  object-position: top;
  border: 3px solid var(--white);
  background: #ececec;
}

.screenshot-item figcaption {
  padding-top: 14px;
  color: #d4d4da;
  font-size: 14px;
}

.path-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  border: 3px solid var(--ink);
}

.path-step {
  position: relative;
  min-height: 240px;
  padding: 28px;
  background: var(--paper);
}

.path-step + .path-step {
  border-left: 3px solid var(--ink);
}

.path-step b {
  display: block;
  color: var(--coral);
  font-size: 52px;
  line-height: 1;
}

.path-step h3 {
  margin: 22px 0 8px;
  font-size: 22px;
}

.path-link,
.text-link {
  border-bottom: 2px solid currentColor;
  color: var(--cyan-dark);
  font-weight: 900;
}

.reviews-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 50px;
  align-items: start;
}

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

.quote-card {
  margin: 0;
  padding: 24px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--white);
  box-shadow: 5px 5px 0 var(--ink);
}

.quote-card p {
  margin: 0 0 10px;
  font-size: 17px;
}

.quote-card cite {
  color: var(--muted);
  font-style: normal;
  font-weight: 700;
}

.review-score {
  position: sticky;
  top: 110px;
  padding: 34px;
  border: 3px solid var(--ink);
  background: var(--yellow);
  box-shadow: var(--shadow);
}

.review-score strong {
  display: block;
  font-size: 72px;
  line-height: 1;
}

.review-score span {
  display: block;
  margin-top: 12px;
  font-weight: 900;
}

.faq-preview {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

details {
  border: 2px solid var(--ink);
  border-radius: 4px;
  background: var(--white);
}

summary {
  padding: 18px 54px 18px 20px;
  font-weight: 900;
  cursor: pointer;
  list-style: none;
  position: relative;
}

summary::-webkit-details-marker {
  display: none;
}

summary::after {
  content: "+";
  position: absolute;
  right: 20px;
  top: 13px;
  font-size: 26px;
}

details[open] summary::after {
  content: "−";
}

details p {
  margin: 0;
  padding: 0 20px 20px;
  color: #45454b;
}

.cta-band {
  padding: 58px 0;
  border-top: 3px solid var(--ink);
  background: var(--yellow);
}

.cta-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 34px;
}

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

.subhero {
  padding: 86px 0 68px;
  border-bottom: 3px solid var(--ink);
  color: var(--white);
  background: var(--ink);
}

.subhero-grid {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 64px;
  align-items: end;
}

.subhero h1 {
  max-width: 820px;
  margin: 0;
  font-size: clamp(40px, 6vw, 72px);
  line-height: 1.08;
  letter-spacing: 0;
}

.subhero-copy {
  max-width: 780px;
  margin: 22px 0 0;
  color: #d0d0d6;
  font-size: 18px;
}

.page-index {
  padding: 24px;
  border: 3px solid var(--white);
  color: var(--ink);
  background: var(--cyan);
  box-shadow: 8px 8px 0 var(--coral);
}

.page-index strong,
.page-index span {
  display: block;
}

.page-index strong {
  font-size: 42px;
  line-height: 1;
}

.page-index span {
  margin-top: 10px;
  font-weight: 900;
}

.article-layout {
  display: grid;
  grid-template-columns: 250px minmax(0, 1fr);
  gap: 64px;
  align-items: start;
}

.side-nav {
  position: sticky;
  top: 100px;
  border-top: 4px solid var(--coral);
}

.side-nav strong {
  display: block;
  padding: 14px 0;
  border-bottom: 2px solid var(--ink);
}

.side-nav a {
  display: block;
  padding: 12px 0;
  border-bottom: 1px solid var(--line);
  font-weight: 700;
}

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

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

.article-content section + section {
  margin-top: 72px;
}

.article-content h2 {
  margin: 0 0 24px;
  padding-bottom: 12px;
  border-bottom: 3px solid var(--ink);
  font-size: clamp(28px, 3vw, 38px);
  line-height: 1.25;
}

.article-content h3 {
  margin: 30px 0 10px;
  font-size: 22px;
}

.article-content p {
  margin: 0 0 16px;
  color: #3f3f45;
}

.step-list {
  counter-reset: steps;
  display: grid;
  gap: 18px;
}

.step-block {
  position: relative;
  padding: 28px 28px 28px 92px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--white);
}

.step-block::before {
  counter-increment: steps;
  content: counter(steps, decimal-leading-zero);
  position: absolute;
  left: 22px;
  top: 24px;
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  color: var(--ink);
  background: var(--cyan);
  font-weight: 900;
}

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

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

.notice {
  padding: 22px;
  border-left: 7px solid var(--coral);
  background: #fff0ee;
}

.notice strong {
  display: block;
  margin-bottom: 6px;
}

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

.settings-table th,
.settings-table td {
  padding: 14px 16px;
  border: 1px solid var(--ink);
  text-align: left;
  vertical-align: top;
}

.settings-table th {
  background: var(--cyan);
}

.article-image {
  width: min(100%, 330px);
  max-width: 400px;
  height: auto;
  margin: 28px auto;
  border: 3px solid var(--ink);
  box-shadow: 9px 9px 0 var(--cyan);
}

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

.feature-detail {
  padding: 24px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--white);
}

.feature-detail h3 {
  margin: 0 0 10px;
}

.feature-detail p:last-child {
  margin-bottom: 0;
}

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

.related-links {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.related-links a {
  padding: 20px;
  border: 2px solid var(--ink);
  background: var(--white);
  box-shadow: 4px 4px 0 var(--ink);
  font-weight: 900;
}

.related-links a:hover {
  background: var(--cyan);
}

.site-footer {
  padding: 56px 0 28px;
  color: #c8c8cf;
  background: var(--ink);
}

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

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

.footer-brand .brand {
  margin-bottom: 14px;
}

.footer-brand p,
.footer-note {
  margin: 0;
  font-size: 14px;
}

.footer-links strong {
  display: block;
  margin-bottom: 10px;
  color: var(--white);
}

.footer-links a {
  display: block;
  padding: 4px 0;
}

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

.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid #3e3e45;
  font-size: 13px;
}

@media (max-width: 900px) {
  .menu-toggle {
    display: block;
  }

  .nav-links {
    position: fixed;
    inset: 72px 0 auto 0;
    display: none;
    padding: 18px 16px 24px;
    border-bottom: 3px solid var(--ink);
    background: var(--paper);
  }

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

  .nav-links > a:not(.download-btn) {
    border-bottom: 1px solid var(--line);
  }

  .hero-grid,
  .subhero-grid {
    grid-template-columns: 1fr;
    gap: 38px;
  }

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

  .hero-visual {
    min-height: 450px;
  }

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

  .fact:nth-child(2) {
    border-right: 2px solid var(--ink);
  }

  .fact:nth-child(n + 3) {
    border-top: 2px solid var(--ink);
  }

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

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

  .path-step + .path-step {
    border-left: 0;
    border-top: 3px solid var(--ink);
  }

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

  .review-score,
  .side-nav {
    position: static;
  }

  .side-nav {
    display: grid;
    grid-template-columns: 1fr 1fr;
  }

  .side-nav strong {
    grid-column: 1 / -1;
  }

  .side-nav a {
    padding-right: 12px;
  }

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

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

@media (max-width: 620px) {
  .nav-shell,
  .container {
    width: min(calc(100% - 22px), var(--max));
  }

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

  .hero h1 {
    font-size: 44px;
  }

  .hero-visual {
    min-height: 390px;
  }

  .hero-stamp {
    width: 94px;
    height: 94px;
    font-size: 15px;
  }

  .facts-grid,
  .feature-grid,
  .faq-preview,
  .feature-detail-grid,
  .related-links,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .fact,
  .fact:last-child,
  .fact:nth-child(2) {
    border-right: 2px solid var(--ink);
  }

  .fact + .fact {
    border-top: 2px solid var(--ink);
  }

  .section {
    padding: 62px 0;
  }

  .shot-toolbar,
  .cta-inner {
    align-items: flex-start;
    flex-direction: column;
  }

  .screenshot-track {
    grid-auto-columns: minmax(210px, 76vw);
  }

  .subhero {
    padding: 62px 0 48px;
  }

  .side-nav {
    grid-template-columns: 1fr;
  }

  .step-block {
    padding: 82px 20px 22px;
  }

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

  .settings-table {
    font-size: 14px;
  }

  .settings-table th,
  .settings-table td {
    padding: 10px;
  }
}

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

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