:root {
  --ink: #171a24;
  --paper: #f7f5ef;
  --white: #ffffff;
  --coral: #ff5d57;
  --coral-dark: #e44743;
  --mint: #31bfa7;
  --blue: #3156d3;
  --line: #dcd9d0;
  --muted: #656978;
  --shadow: 0 18px 44px rgba(23, 26, 36, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "微软雅黑", Arial, Helvetica, sans-serif;
  line-height: 1.75;
}

body::before {
  position: fixed;
  z-index: -1;
  inset: 0;
  background-image: linear-gradient(rgba(23, 26, 36, 0.035) 1px, transparent 1px), linear-gradient(90deg, rgba(23, 26, 36, 0.035) 1px, transparent 1px);
  background-size: 32px 32px;
  content: "";
  pointer-events: none;
}

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

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

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

.container {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  z-index: 50;
  top: 0;
  border-bottom: 1px solid rgba(23, 26, 36, 0.12);
  background: rgba(247, 245, 239, 0.94);
  backdrop-filter: blur(18px);
}

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

.brand {
  display: inline-flex;
  align-items: center;
  flex: 0 0 auto;
  gap: 10px;
  font-size: 22px;
  font-weight: 800;
  letter-spacing: 0;
}

.brand img {
  width: 42px;
  height: 42px;
  border: 2px solid var(--ink);
  border-radius: 8px;
}

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

.site-nav a {
  padding: 8px 14px;
  border-bottom: 2px solid transparent;
  font-size: 15px;
  font-weight: 700;
}

.site-nav a:hover,
.site-nav a.active {
  border-color: var(--coral);
  color: var(--coral-dark);
}

.site-nav .nav-download {
  margin-left: 8px;
  padding: 9px 18px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--coral);
  box-shadow: 3px 3px 0 var(--ink);
  color: var(--white);
}

.site-nav .nav-download:hover {
  border-color: var(--ink);
  color: var(--white);
  transform: translate(2px, 2px);
  box-shadow: 1px 1px 0 var(--ink);
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--white);
  color: var(--ink);
  font-size: 23px;
  cursor: pointer;
}

.hero {
  position: relative;
  overflow: hidden;
  padding: 68px 0 74px;
  border-bottom: 2px solid var(--ink);
}

.hero::after {
  position: absolute;
  z-index: -1;
  right: -80px;
  bottom: 24px;
  width: 310px;
  height: 120px;
  border: 2px solid var(--ink);
  background: var(--mint);
  content: "";
  transform: rotate(-8deg);
}

.hero-grid {
  display: grid;
  align-items: center;
  grid-template-columns: minmax(0, 1.04fr) minmax(320px, 0.96fr);
  gap: 64px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 18px;
  color: var(--blue);
  font-size: 14px;
  font-weight: 800;
}

.eyebrow::before {
  width: 30px;
  height: 4px;
  background: var(--blue);
  content: "";
}

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

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

h1 {
  max-width: 720px;
  margin-bottom: 22px;
  font-size: 72px;
  font-weight: 900;
}

.hero-copy > p:not(.eyebrow) {
  max-width: 650px;
  margin-bottom: 28px;
  color: #434754;
  font-size: 18px;
}

.hero-actions,
.action-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
}

.button {
  display: inline-flex;
  min-height: 50px;
  align-items: center;
  justify-content: center;
  padding: 11px 24px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--coral);
  box-shadow: 4px 4px 0 var(--ink);
  color: var(--white);
  font-weight: 800;
  transition: transform 160ms ease, box-shadow 160ms ease;
}

.button:hover {
  transform: translate(3px, 3px);
  box-shadow: 1px 1px 0 var(--ink);
}

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

.micro-note {
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.hero-visual {
  position: relative;
  min-height: 510px;
}

.phone-shot {
  position: absolute;
  width: min(280px, 74%);
  max-width: 400px;
  height: auto;
  overflow: hidden;
  border: 3px solid var(--ink);
  border-radius: 8px;
  background: var(--white);
  box-shadow: var(--shadow);
}

.phone-shot.primary {
  z-index: 2;
  top: 0;
  right: 4%;
  transform: rotate(3deg);
}

.phone-shot.secondary-shot {
  z-index: 1;
  bottom: -12px;
  left: 0;
  width: min(238px, 62%);
  transform: rotate(-6deg);
}

.hero-sticker {
  position: absolute;
  z-index: 3;
  right: 1%;
  bottom: 28px;
  width: 132px;
  padding: 16px 12px;
  border: 2px solid var(--ink);
  background: #fff36d;
  box-shadow: 4px 4px 0 var(--ink);
  font-size: 14px;
  font-weight: 900;
  line-height: 1.35;
  text-align: center;
  transform: rotate(5deg);
}

.stat-strip {
  border-bottom: 2px solid var(--ink);
  background: var(--ink);
  color: var(--white);
}

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

.stat-item {
  padding: 22px 28px;
  border-right: 1px solid rgba(255, 255, 255, 0.2);
}

.stat-item:last-child {
  border-right: 0;
}

.stat-item strong,
.stat-item span {
  display: block;
}

.stat-item strong {
  color: #fff36d;
  font-size: 21px;
}

.stat-item span {
  color: #d4d5da;
  font-size: 13px;
}

.section {
  padding: 88px 0;
}

.section.alt {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: var(--white);
}

.section-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 28px;
  margin-bottom: 38px;
}

.section-heading h2,
.content-header h1 {
  margin: 0;
  font-size: 52px;
  font-weight: 900;
}

.section-number {
  color: var(--coral);
  font: 800 14px/1 Consolas, Monaco, monospace;
}

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

.feature-card {
  position: relative;
  min-height: 230px;
  padding: 28px;
  overflow: hidden;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--white);
}

.feature-card:nth-child(2) {
  background: #e7fbf5;
}

.feature-card:nth-child(3) {
  background: #eef1ff;
}

.feature-index {
  display: inline-flex;
  width: 38px;
  height: 38px;
  align-items: center;
  justify-content: center;
  margin-bottom: 30px;
  border: 2px solid var(--ink);
  border-radius: 50%;
  background: #fff36d;
  font: 800 14px/1 Consolas, Monaco, monospace;
}

.feature-card h3 {
  margin-bottom: 10px;
  font-size: 22px;
}

.feature-card p {
  margin: 0;
  color: #555966;
}

.gallery-track {
  display: grid;
  align-items: start;
  grid-template-columns: repeat(5, minmax(210px, 1fr));
  gap: 22px;
  overflow-x: auto;
  padding: 8px 4px 28px;
  scrollbar-color: var(--coral) var(--line);
}

.screen-card {
  min-width: 210px;
}

.screen-card img {
  width: 100%;
  max-width: 360px;
  height: auto;
  border: 2px solid var(--ink);
  border-radius: 6px;
  box-shadow: 7px 7px 0 rgba(23, 26, 36, 0.14);
}

.screen-card p {
  margin: 16px 0 0;
  font-size: 14px;
  font-weight: 800;
}

.split-layout {
  display: grid;
  align-items: start;
  grid-template-columns: 0.86fr 1.14fr;
  gap: 70px;
}

.split-title {
  position: sticky;
  top: 112px;
}

.split-title h2 {
  margin-bottom: 24px;
  font-size: 52px;
  font-weight: 900;
}

.link-arrow {
  display: inline-flex;
  align-items: center;
  border-bottom: 2px solid var(--ink);
  font-weight: 800;
}

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

.story-item {
  display: grid;
  padding: 26px 0;
  border-bottom: 1px solid var(--line);
  grid-template-columns: 54px 1fr;
  gap: 18px;
}

.story-item span {
  color: var(--coral-dark);
  font: 800 15px/1.6 Consolas, Monaco, monospace;
}

.story-item h3 {
  margin-bottom: 8px;
  font-size: 22px;
}

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

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

.quote-card {
  margin: 0;
  padding: 26px;
  border: 2px solid var(--ink);
  border-radius: 6px;
  background: var(--white);
  box-shadow: 5px 5px 0 var(--mint);
}

.quote-card blockquote {
  margin: 0 0 18px;
  font-size: 16px;
}

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

.download-band {
  padding: 60px 0;
  border-top: 2px solid var(--ink);
  border-bottom: 2px solid var(--ink);
  background: var(--blue);
  color: var(--white);
}

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

.download-inner h2 {
  max-width: 720px;
  margin: 0;
  font-size: 46px;
}

.download-inner .button {
  flex: 0 0 auto;
  background: #fff36d;
  color: var(--ink);
}

.content-hero {
  padding: 68px 0 54px;
  border-bottom: 2px solid var(--ink);
}

.content-header {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 60px;
  align-items: end;
}

.content-header h1 {
  margin-bottom: 20px;
}

.content-header p {
  max-width: 760px;
  margin: 0;
  color: #4d515e;
  font-size: 17px;
}

.chapter-mark {
  display: flex;
  min-height: 180px;
  align-items: center;
  justify-content: center;
  border: 2px solid var(--ink);
  background: var(--coral);
  box-shadow: 8px 8px 0 var(--ink);
  color: var(--white);
  font: 900 56px/1 Consolas, Monaco, monospace;
  transform: rotate(3deg);
}

.guide-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px;
}

.guide-step {
  padding: 30px;
  border-left: 6px solid var(--coral);
  background: var(--white);
  box-shadow: 0 10px 30px rgba(23, 26, 36, 0.07);
}

.guide-step:nth-child(even) {
  border-left-color: var(--mint);
}

.guide-step .step-no {
  display: block;
  margin-bottom: 18px;
  color: var(--blue);
  font: 800 14px/1 Consolas, Monaco, monospace;
}

.guide-step h2,
.guide-step h3 {
  margin-bottom: 12px;
  font-size: 25px;
}

.guide-step p:last-child,
.guide-step ul:last-child {
  margin-bottom: 0;
}

.check-list {
  margin: 16px 0 0;
  padding: 0;
  list-style: none;
}

.check-list li {
  position: relative;
  margin: 8px 0;
  padding-left: 26px;
}

.check-list li::before {
  position: absolute;
  top: 0;
  left: 0;
  color: var(--mint);
  content: "✓";
  font-weight: 900;
}

.notice {
  margin-top: 28px;
  padding: 22px 24px;
  border: 2px solid var(--ink);
  background: #fff6c9;
  font-size: 14px;
}

.article-layout {
  display: grid;
  align-items: start;
  grid-template-columns: minmax(0, 1fr) 290px;
  gap: 60px;
}

.article-body h2 {
  margin: 48px 0 20px;
  font-size: 32px;
}

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

.article-body h3 {
  margin: 28px 0 10px;
  font-size: 21px;
}

.article-body p {
  color: #454956;
}

.side-panel {
  position: sticky;
  top: 108px;
  padding: 24px;
  border: 2px solid var(--ink);
  background: var(--white);
  box-shadow: 6px 6px 0 var(--mint);
}

.side-panel strong {
  display: block;
  margin-bottom: 14px;
  font-size: 18px;
}

.side-panel a:not(.button) {
  display: block;
  padding: 9px 0;
  border-bottom: 1px solid var(--line);
  font-size: 14px;
  font-weight: 700;
}

.side-panel .button {
  width: 100%;
  margin-top: 20px;
}

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

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

.faq-question {
  display: grid;
  width: 100%;
  padding: 22px 4px;
  border: 0;
  background: transparent;
  color: var(--ink);
  cursor: pointer;
  font-family: inherit;
  font-size: 17px;
  font-weight: 800;
  line-height: 1.5;
  grid-template-columns: 1fr 30px;
  text-align: left;
}

.faq-question::after {
  content: "+";
  font-size: 25px;
  line-height: 1;
  text-align: center;
}

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

.faq-answer {
  display: none;
  max-width: 850px;
  padding: 0 42px 22px 4px;
  color: #555966;
}

.faq-answer p:last-child {
  margin-bottom: 0;
}

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

.related-links {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
}

.related-link {
  padding: 24px;
  border: 2px solid var(--ink);
  background: var(--white);
  font-weight: 800;
}

.related-link span {
  display: block;
  margin-top: 8px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 500;
}

.site-footer {
  padding: 42px 0 28px;
  background: var(--ink);
  color: #d9dae0;
}

.footer-grid {
  display: grid;
  margin-bottom: 28px;
  grid-template-columns: 1fr auto;
  gap: 32px;
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--white);
  font-size: 21px;
  font-weight: 900;
}

.footer-brand img {
  width: 38px;
  height: 38px;
  border-radius: 6px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 20px;
  font-size: 14px;
}

.footer-links a:hover {
  color: #fff36d;
}

.disclaimer,
.copyright {
  margin: 0;
  padding-top: 16px;
  border-top: 1px solid rgba(255, 255, 255, 0.14);
  color: #aeb0ba;
  font-size: 12px;
}

.copyright {
  margin-top: 8px;
  padding-top: 0;
  border-top: 0;
}

[data-reveal] {
  opacity: 1;
  transform: none;
  transition: opacity 500ms ease, transform 500ms ease;
}

[data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
}

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

  [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

@media (max-width: 900px) {
  h1,
  .section-heading h2,
  .content-header h1,
  .split-title h2 {
    font-size: 48px;
  }

  .download-inner h2 {
    font-size: 40px;
  }

  .nav-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .site-nav {
    position: absolute;
    top: 74px;
    right: 20px;
    left: 20px;
    display: none;
    padding: 14px;
    border: 2px solid var(--ink);
    background: var(--white);
    box-shadow: 6px 6px 0 var(--ink);
    flex-direction: column;
    align-items: stretch;
  }

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

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

  .site-nav .nav-download {
    margin: 8px 0 0;
    text-align: center;
  }

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

  .hero-grid {
    gap: 42px;
  }

  .hero-visual {
    min-height: 550px;
  }

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

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

  .split-title,
  .side-panel {
    position: static;
  }

  .content-header {
    grid-template-columns: 1fr 160px;
    gap: 30px;
  }

  .chapter-mark {
    min-height: 130px;
    font-size: 42px;
  }
}

@media (max-width: 680px) {
  .container {
    width: min(100% - 28px, 1180px);
  }

  .hero,
  .content-hero {
    padding-top: 48px;
  }

  h1 {
    font-size: 42px;
  }

  .section-heading h2,
  .content-header h1,
  .split-title h2 {
    font-size: 38px;
  }

  .download-inner h2 {
    font-size: 34px;
  }

  .hero-copy > p:not(.eyebrow) {
    font-size: 16px;
  }

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

  .phone-shot.primary {
    right: 0;
  }

  .hero-sticker {
    right: 0;
    bottom: 0;
    width: 112px;
  }

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

  .stat-item:nth-child(2) {
    border-right: 0;
  }

  .section {
    padding: 62px 0;
  }

  .section-heading,
  .download-inner,
  .footer-grid {
    align-items: flex-start;
    flex-direction: column;
  }

  .section-heading {
    display: block;
  }

  .section-number {
    display: block;
    margin-bottom: 12px;
  }

  .download-inner,
  .footer-grid {
    display: flex;
  }

  .guide-grid,
  .related-links {
    grid-template-columns: 1fr;
  }

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

  .chapter-mark {
    width: 120px;
    min-height: 100px;
  }

  .footer-links {
    align-items: flex-start;
    flex-direction: column;
    gap: 10px;
  }
}