:root {
  --ink: #14211d;
  --muted: #5c6b65;
  --paper: #f7f8f5;
  --white: #ffffff;
  --green: #1d6b4f;
  --green-dark: #124634;
  --yellow: #f2d13d;
  --coral: #f05a47;
  --blue: #2f6f9f;
  --line: #dce4df;
  --shadow: 0 18px 45px rgba(20, 33, 29, 0.12);
  --content: 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;
}

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

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

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

.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 1000;
  padding: 8px 12px;
  color: var(--white);
  background: var(--green-dark);
  transform: translateY(-150%);
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid rgba(20, 33, 29, 0.08);
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(14px);
}

.nav-wrap {
  width: min(calc(100% - 32px), var(--content));
  min-height: 72px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 30px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
  font-size: 20px;
  font-weight: 800;
  line-height: 1;
}

.brand img {
  width: 44px;
  height: 44px;
  border-radius: 10px;
}

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  margin-left: auto;
  border: 1px solid var(--line);
  background: var(--white);
  cursor: pointer;
}

.nav-toggle span,
.nav-toggle::before,
.nav-toggle::after {
  display: block;
  width: 20px;
  height: 2px;
  margin: 4px auto;
  content: "";
  background: var(--ink);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-left: auto;
}

.site-nav a {
  min-height: 40px;
  padding: 7px 12px;
  border-bottom: 2px solid transparent;
  font-weight: 700;
}

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

.button,
.site-nav .nav-download {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  padding: 11px 22px;
  border: 2px solid var(--green-dark);
  border-radius: 6px;
  color: var(--white);
  background: var(--green);
  box-shadow: 4px 4px 0 var(--green-dark);
  font-weight: 800;
  line-height: 1.25;
  transition: transform 160ms ease, box-shadow 160ms ease;
}

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

.button-secondary {
  color: var(--ink);
  background: var(--yellow);
  border-color: var(--ink);
  box-shadow: 4px 4px 0 var(--ink);
}

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

.band {
  padding: 88px 0;
}

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

.band-green {
  color: var(--white);
  background: var(--green-dark);
}

.section-heading {
  margin: 0 0 34px;
  font-size: 46px;
  line-height: 1.2;
}

.section-heading::after {
  display: block;
  width: 72px;
  height: 7px;
  margin-top: 14px;
  content: "";
  background: var(--yellow);
}

.eyebrow {
  display: inline-block;
  margin-bottom: 18px;
  padding: 4px 10px;
  color: var(--green-dark);
  background: var(--yellow);
  border: 1px solid var(--ink);
  font-size: 13px;
  font-weight: 800;
}

.hero {
  position: relative;
  overflow: hidden;
  min-height: 650px;
  padding: 72px 0 64px;
  background: var(--white);
}

.hero::before {
  position: absolute;
  top: 34px;
  right: 7%;
  width: 140px;
  height: 140px;
  border: 18px solid var(--yellow);
  content: "";
  transform: rotate(11deg);
  z-index: 2;
}

.hero::after {
  position: absolute;
  right: 0;
  bottom: 0;
  z-index: 0;
  width: 58%;
  height: 100%;
  content: "";
  background: #dfeee7;
  clip-path: polygon(46% 0, 100% 0, 100% 100%, 0 100%);
}

.hero-grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(380px, 0.85fr);
  align-items: center;
  gap: 70px;
}

.hero h1 {
  max-width: 720px;
  margin: 0;
  font-size: 82px;
  line-height: 1.05;
}

.hero-copy {
  max-width: 640px;
  margin: 24px 0 0;
  color: #344940;
  font-size: 19px;
}

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

.hero-notes {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  margin: 26px 0 0;
  padding: 0;
  color: var(--muted);
  list-style: none;
  font-size: 14px;
  font-weight: 700;
}

.hero-notes li::before {
  margin-right: 7px;
  color: var(--green);
  content: "✓";
}

.phone-stage {
  position: relative;
  min-height: 520px;
}

.phone {
  position: absolute;
  width: min(47%, 268px);
  overflow: hidden;
  border: 8px solid var(--ink);
  border-radius: 26px;
  background: var(--white);
  box-shadow: var(--shadow);
}

.phone:first-child {
  top: 14px;
  left: 4%;
  transform: rotate(-4deg);
}

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

.phone img,
.preview-card img,
.step-visual img {
  width: 100%;
  max-width: 400px;
  height: auto;
}

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

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

.signal-item {
  min-height: 104px;
  padding: 20px 24px;
  border-right: 1px solid var(--line);
}

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

.signal-item strong {
  display: block;
  color: var(--green);
  font-size: 22px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.feature-item {
  min-height: 230px;
  padding: 30px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: var(--white);
}

.feature-number {
  display: inline-flex;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
  color: var(--white);
  background: var(--coral);
  border-radius: 50%;
  font-weight: 800;
}

.feature-item h3,
.path-panel h3 {
  margin: 0 0 10px;
  font-size: 22px;
}

.feature-item p,
.path-panel p,
.review blockquote {
  margin: 0;
  color: var(--muted);
}

.preview-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 20px;
}

.preview-card {
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #eef2ef;
}

.preview-card img {
  margin: 0 auto;
}

.preview-card figcaption {
  min-height: 94px;
  padding: 16px;
  color: var(--muted);
  background: var(--white);
  border-top: 1px solid var(--line);
  font-size: 14px;
}

.preview-card strong {
  display: block;
  color: var(--ink);
  font-size: 17px;
}

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

.path-panel {
  min-height: 300px;
  padding: 34px;
  border: 2px solid var(--ink);
  background: var(--white);
  box-shadow: 8px 8px 0 var(--yellow);
}

.path-panel:nth-child(2) {
  box-shadow: 8px 8px 0 var(--coral);
}

.text-link {
  display: inline-block;
  margin-top: 28px;
  color: var(--green);
  border-bottom: 2px solid var(--green);
  font-weight: 800;
}

.review-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}

.review {
  padding: 28px;
  border-top: 6px solid var(--yellow);
  background: var(--white);
}

.review:nth-child(2) {
  border-top-color: var(--coral);
}

.review:nth-child(3) {
  border-top-color: var(--blue);
}

.review cite {
  display: block;
  margin-top: 18px;
  color: var(--ink);
  font-style: normal;
  font-weight: 800;
}

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

.faq-list details {
  border: 1px solid var(--line);
  background: var(--white);
}

.faq-list summary {
  position: relative;
  padding: 18px 54px 18px 20px;
  cursor: pointer;
  font-weight: 800;
  list-style: none;
}

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

.faq-list summary::after {
  position: absolute;
  top: 17px;
  right: 20px;
  color: var(--green);
  content: "+";
  font-size: 24px;
  line-height: 1;
}

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

.faq-answer {
  padding: 0 20px 20px;
  color: var(--muted);
}

.faq-answer p {
  margin: 0;
}

.download-band {
  padding: 64px 0;
  background: var(--yellow);
}

.download-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 36px;
}

.download-wrap h2 {
  margin: 0;
  font-size: 48px;
  line-height: 1.2;
}

.site-footer {
  padding: 42px 0 28px;
  color: #d9e5df;
  background: var(--ink);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 40px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 10px 22px;
}

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

.disclaimer {
  margin: 28px 0 0;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.16);
  color: #aebdb6;
  font-size: 13px;
}

.subhero {
  padding: 78px 0;
  color: var(--white);
  background: var(--green-dark);
}

.subhero h1 {
  max-width: 880px;
  margin: 0;
  font-size: 68px;
  line-height: 1.12;
}

.subhero p {
  max-width: 760px;
  margin: 22px 0 0;
  color: #d7e8df;
  font-size: 18px;
}

.guide-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 270px;
  gap: 54px;
  align-items: start;
}

.guide-nav {
  position: sticky;
  top: 100px;
  padding: 22px;
  border-left: 5px solid var(--yellow);
  background: var(--white);
}

.guide-nav strong {
  display: block;
  margin-bottom: 10px;
}

.guide-nav a {
  display: block;
  padding: 7px 0;
  color: var(--muted);
}

.guide-nav a:hover {
  color: var(--green);
}

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

.step-card {
  display: grid;
  grid-template-columns: 78px minmax(0, 1fr);
  gap: 24px;
  padding: 30px;
  border: 1px solid var(--line);
  background: var(--white);
}

.step-count {
  display: flex;
  width: 64px;
  height: 64px;
  align-items: center;
  justify-content: center;
  color: var(--white);
  background: var(--green);
  border-radius: 50%;
  font-size: 24px;
  font-weight: 800;
}

.step-card h2,
.content-block h2 {
  margin: 0 0 14px;
  font-size: 28px;
  line-height: 1.3;
}

.step-card p,
.content-block p {
  margin: 0 0 14px;
  color: var(--muted);
}

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

.content-stack {
  display: grid;
  gap: 26px;
}

.content-block {
  padding: 30px;
  border: 1px solid var(--line);
  background: var(--white);
}

.check-list,
.plain-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.check-list li,
.plain-list li {
  position: relative;
  padding: 10px 0 10px 28px;
  border-bottom: 1px solid var(--line);
}

.check-list li::before {
  position: absolute;
  left: 0;
  color: var(--green);
  content: "✓";
  font-weight: 800;
}

.plain-list li::before {
  position: absolute;
  left: 4px;
  color: var(--coral);
  content: "•";
  font-weight: 800;
}

.split-content {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.feature-detail {
  padding: 26px;
  border: 1px solid var(--line);
  background: var(--white);
}

.feature-detail h2 {
  margin: 0 0 10px;
  font-size: 24px;
}

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

.related-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.related-links a {
  padding: 9px 13px;
  border: 1px solid var(--green);
  color: var(--green);
  background: var(--white);
  font-weight: 700;
}

@media (max-width: 920px) {
  .hero-grid,
  .guide-layout {
    grid-template-columns: 1fr;
  }

  .hero {
    padding-bottom: 40px;
  }

  .hero h1 {
    font-size: 62px;
  }

  .section-heading {
    font-size: 40px;
  }

  .subhero h1 {
    font-size: 54px;
  }

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

  .phone-stage {
    width: min(100%, 560px);
    margin: 0 auto;
  }

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

  .preview-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (max-width: 720px) {
  .nav-wrap {
    min-height: 64px;
    flex-wrap: wrap;
  }

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

  .nav-toggle {
    display: block;
  }

  .site-nav {
    display: none;
    width: 100%;
    margin: 0 0 14px;
    padding-top: 8px;
    border-top: 1px solid var(--line);
    flex-direction: column;
    align-items: stretch;
  }

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

  .site-nav a {
    text-align: center;
  }

  .hero {
    min-height: auto;
    padding-top: 52px;
  }

  .hero::before {
    display: none;
  }

  .hero h1 {
    font-size: 46px;
  }

  .subhero h1 {
    font-size: 40px;
  }

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

  .phone-stage {
    min-height: 430px;
  }

  .phone {
    width: 52%;
    border-width: 6px;
    border-radius: 20px;
  }

  .signal-grid,
  .feature-grid,
  .review-grid,
  .path-grid,
  .split-content,
  .footer-grid {
    grid-template-columns: 1fr;
  }

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

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

  .signal-item:nth-child(-n+2) {
    border-bottom: 1px solid var(--line);
  }

  .band {
    padding: 62px 0;
  }

  .section-heading {
    font-size: 32px;
  }

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

  .download-wrap {
    align-items: flex-start;
    flex-direction: column;
  }

  .footer-links {
    justify-content: flex-start;
  }

  .step-card {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 460px) {
  .preview-grid {
    grid-template-columns: 1fr;
  }

  .preview-card {
    width: min(100%, 320px);
    margin: 0 auto;
  }

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

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

  .signal-item,
  .signal-item:nth-child(2) {
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition: none !important;
  }
}