:root {
  --ink: #071329;
  --ink-soft: #102448;
  --paper: #f6f8fc;
  --white: #ffffff;
  --text: #17233b;
  --muted: #637089;
  --line: #dce3ef;
  --cyan: #27b8cf;
  --cyan-dark: #118aa2;
  --coral: #ef5c78;
  --gold: #e7ae38;
  --mint: #8ce0c1;
  --shadow: 0 18px 50px rgba(7, 19, 41, 0.12);
  --radius: 8px;
  --container: 1160px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  overflow-x: hidden;
}

body {
  margin: 0;
  overflow-x: hidden;
  color: var(--text);
  background: var(--paper);
  font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.75;
}

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 {
  font: inherit;
}

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

.skip-link {
  position: fixed;
  z-index: 200;
  top: 8px;
  left: 8px;
  padding: 8px 14px;
  color: var(--ink);
  background: var(--white);
  transform: translateY(-150%);
}

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

.site-header {
  position: sticky;
  z-index: 100;
  top: 0;
  color: var(--white);
  background: rgba(7, 19, 41, 0.96);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(14px);
}

.nav-shell {
  min-height: 72px;
  display: flex;
  align-items: center;
  gap: 34px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  font-size: 20px;
  font-weight: 800;
  white-space: nowrap;
}

.brand img {
  width: 42px;
  height: 42px;
  border-radius: 8px;
}

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

.site-nav a {
  padding: 9px 13px;
  color: #d5deef;
  font-size: 14px;
  font-weight: 700;
  border-bottom: 2px solid transparent;
}

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

.download-button {
  min-height: 46px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 11px 21px;
  color: var(--ink);
  background: var(--gold);
  border: 1px solid var(--gold);
  border-radius: 6px;
  box-shadow: 0 8px 22px rgba(231, 174, 56, 0.2);
  font-weight: 800;
  line-height: 1.2;
  transition: transform 180ms ease, box-shadow 180ms ease, background 180ms ease;
}

.download-button::before {
  content: "↓";
  font-size: 18px;
  line-height: 1;
}

.download-button:hover {
  background: #f1c257;
  box-shadow: 0 12px 26px rgba(231, 174, 56, 0.28);
  transform: translateY(-2px);
}

.outline-button {
  min-height: 46px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 11px 21px;
  color: var(--white);
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.42);
  border-radius: 6px;
  font-weight: 800;
  line-height: 1.2;
  transition: transform 180ms ease, background 180ms ease;
}

.outline-button:hover {
  background: rgba(255, 255, 255, 0.08);
  transform: translateY(-2px);
}

.nav-download {
  min-height: 40px;
  padding: 8px 15px;
  color: var(--ink) !important;
  border-bottom: 1px solid var(--gold) !important;
}

.menu-toggle {
  width: 44px;
  height: 44px;
  display: none;
  align-items: center;
  justify-content: center;
  margin-left: auto;
  color: var(--white);
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: 6px;
  cursor: pointer;
}

.menu-toggle span {
  font-size: 24px;
  line-height: 1;
}

.hero {
  position: relative;
  min-height: 650px;
  overflow: hidden;
  color: var(--white);
  background: var(--ink);
}

.hero::after {
  position: absolute;
  right: -12%;
  bottom: -48%;
  width: 720px;
  height: 720px;
  content: "";
  border: 1px solid rgba(88, 213, 232, 0.22);
  border-radius: 50%;
  box-shadow: inset 0 0 0 110px rgba(39, 184, 207, 0.035), inset 0 0 0 220px rgba(239, 92, 120, 0.025);
}

.hero-layout {
  position: relative;
  z-index: 2;
  min-height: 650px;
  display: grid;
  grid-template-columns: minmax(0, 1.03fr) minmax(390px, 0.97fr);
  align-items: center;
  gap: 70px;
  padding-top: 48px;
  padding-bottom: 54px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  margin-bottom: 18px;
  color: var(--mint);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0;
}

.eyebrow::before {
  width: 28px;
  height: 2px;
  content: "";
  background: var(--coral);
}

.hero h1 {
  max-width: 640px;
  margin: 0;
  font-size: clamp(38px, 5vw, 66px);
  line-height: 1.12;
  letter-spacing: 0;
}

.hero h1 + p {
  max-width: 670px;
  margin: 22px 0 0;
  color: #cbd7eb;
  font-size: 18px;
  line-height: 1.85;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.hero-facts {
  display: flex;
  flex-wrap: wrap;
  gap: 11px 24px;
  margin: 25px 0 0;
  padding: 0;
  color: #aebbd2;
  font-size: 13px;
  list-style: none;
}

.hero-facts li::before {
  margin-right: 7px;
  color: var(--cyan);
  content: "●";
}

.device-stage {
  position: relative;
  min-height: 510px;
}

.phone {
  position: absolute;
  width: 220px;
  padding: 9px;
  background: #020712;
  border: 1px solid rgba(255, 255, 255, 0.26);
  border-radius: 30px;
  box-shadow: 0 30px 70px rgba(0, 0, 0, 0.45);
}

.phone::before {
  position: absolute;
  z-index: 2;
  top: 13px;
  left: 50%;
  width: 54px;
  height: 5px;
  content: "";
  background: rgba(0, 0, 0, 0.62);
  border-radius: 5px;
  transform: translateX(-50%);
}

.phone img {
  width: 100%;
  border-radius: 22px;
  height: auto;
}

.phone.front {
  z-index: 3;
  top: 5px;
  right: 40px;
}

.phone.back {
  z-index: 1;
  top: 58px;
  left: 8px;
  transform: rotate(-5deg);
}

.orbit-label {
  position: absolute;
  z-index: 4;
  right: 0;
  bottom: 54px;
  width: 156px;
  padding: 14px 16px;
  color: var(--ink);
  background: var(--mint);
  border-left: 5px solid var(--coral);
  border-radius: 6px;
  box-shadow: var(--shadow);
  font-size: 13px;
  font-weight: 800;
  line-height: 1.55;
}

.section {
  padding: 92px 0;
}

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

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

.section-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 30px;
  margin-bottom: 38px;
}

.section-heading h2 {
  margin: 0;
  color: var(--ink);
  font-size: clamp(28px, 4vw, 42px);
  line-height: 1.25;
  letter-spacing: 0;
}

.dark .section-heading h2 {
  color: var(--white);
}

.section-index {
  color: var(--coral);
  font-size: 14px;
  font-weight: 900;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.feature-card {
  min-height: 255px;
  padding: 28px 24px;
  background: var(--white);
  border: 1px solid var(--line);
  border-top: 4px solid var(--cyan);
  border-radius: var(--radius);
}

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

.feature-card:nth-child(3) {
  border-top-color: var(--gold);
}

.feature-card:nth-child(4) {
  border-top-color: var(--mint);
}

.feature-mark {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  color: var(--white);
  background: var(--ink);
  border-radius: 6px;
  font-size: 13px;
  font-weight: 900;
}

.feature-card h3 {
  margin: 20px 0 9px;
  font-size: 20px;
  line-height: 1.4;
}

.feature-card p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.screen-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 24px;
}

.screen-item {
  margin: 0;
}

.screen-frame {
  max-width: 300px;
  padding: 10px;
  margin: 0 auto;
  background: #020712;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 28px;
  box-shadow: 0 22px 48px rgba(0, 0, 0, 0.25);
}

.screen-frame img {
  width: 100%;
  max-width: 400px;
  height: auto;
  border-radius: 20px;
}

.screen-item figcaption {
  margin-top: 18px;
  color: #c4cee0;
  font-size: 14px;
  text-align: center;
}

.path-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.path-link {
  position: relative;
  min-height: 280px;
  overflow: hidden;
  padding: 34px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: transform 180ms ease, border-color 180ms ease;
}

.path-link:hover {
  border-color: var(--cyan);
  transform: translateY(-3px);
}

.path-link::after {
  position: absolute;
  right: 28px;
  bottom: 20px;
  color: var(--cyan-dark);
  content: "→";
  font-size: 34px;
  font-weight: 800;
}

.path-number {
  color: var(--coral);
  font-size: 13px;
  font-weight: 900;
}

.path-link h3 {
  max-width: 420px;
  margin: 54px 0 13px;
  font-size: 28px;
  line-height: 1.3;
}

.path-link p {
  max-width: 480px;
  margin: 0;
  color: var(--muted);
}

.proof-band {
  padding: 54px 0;
  color: var(--white);
  background: var(--ink);
  border-top: 5px solid var(--coral);
}

.proof-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr 1.1fr;
  gap: 30px;
  align-items: center;
}

.score strong {
  display: block;
  color: var(--gold);
  font-size: 50px;
  line-height: 1;
}

.score span {
  color: #aebbd2;
  font-size: 13px;
}

.quote {
  margin: 0;
  padding-left: 22px;
  border-left: 2px solid var(--cyan);
  color: #dce4f2;
}

.quote cite {
  display: block;
  margin-top: 10px;
  color: var(--mint);
  font-size: 13px;
  font-style: normal;
}

.faq-preview {
  border-top: 1px solid var(--line);
}

.faq-preview a {
  display: grid;
  grid-template-columns: 42px 1fr auto;
  align-items: center;
  gap: 16px;
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
  font-weight: 800;
}

.faq-preview a:hover {
  color: var(--cyan-dark);
}

.faq-preview b {
  color: var(--coral);
  font-size: 13px;
}

.download-band {
  padding: 64px 0;
  color: var(--white);
  background: var(--cyan-dark);
}

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

.download-layout h2 {
  margin: 0;
  font-size: clamp(28px, 4vw, 42px);
  line-height: 1.25;
}

.download-layout p {
  margin: 10px 0 0;
  color: #dcf8fc;
}

.download-note {
  margin-top: 10px;
  color: #dcf8fc;
}

.page-hero {
  position: relative;
  overflow: hidden;
  padding: 92px 0 78px;
  color: var(--white);
  background: var(--ink);
  border-bottom: 6px solid var(--cyan);
}

.page-hero::before {
  position: absolute;
  top: -160px;
  right: -80px;
  width: 460px;
  height: 460px;
  content: "";
  border: 1px solid rgba(231, 174, 56, 0.24);
  border-radius: 50%;
  box-shadow: inset 0 0 0 88px rgba(39, 184, 207, 0.04), inset 0 0 0 176px rgba(239, 92, 120, 0.035);
}

.page-hero .container {
  position: relative;
  z-index: 2;
}

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 24px;
  color: #98a8c5;
  font-size: 13px;
}

.breadcrumbs a:hover {
  color: var(--white);
}

.page-hero h1 {
  max-width: 820px;
  margin: 0;
  font-size: clamp(34px, 5vw, 58px);
  line-height: 1.18;
  letter-spacing: 0;
}

.page-hero p {
  max-width: 760px;
  margin: 22px 0 0;
  color: #c9d4e8;
  font-size: 18px;
}

.page-actions {
  margin-top: 28px;
}

.content-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 56px;
  align-items: start;
}

.article-body h2 {
  margin: 0 0 28px;
  color: var(--ink);
  font-size: 32px;
  line-height: 1.3;
}

.article-body h3 {
  margin: 0 0 10px;
  font-size: 21px;
  line-height: 1.45;
}

.article-body p {
  margin: 0 0 18px;
  color: #44516a;
}

.step-list {
  display: grid;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.step-item {
  display: grid;
  grid-template-columns: 74px minmax(0, 1fr);
  gap: 24px;
  padding: 34px 0;
  border-bottom: 1px solid var(--line);
}

.step-number {
  width: 58px;
  height: 58px;
  display: grid;
  place-items: center;
  color: var(--ink);
  background: var(--gold);
  border-radius: 50%;
  font-size: 17px;
  font-weight: 900;
}

.step-detail ul,
.check-list {
  margin: 14px 0 0;
  padding: 0;
  list-style: none;
}

.step-detail li,
.check-list li {
  position: relative;
  margin: 8px 0;
  padding-left: 22px;
  color: #536078;
}

.step-detail li::before,
.check-list li::before {
  position: absolute;
  left: 0;
  color: var(--cyan-dark);
  content: "✓";
  font-weight: 900;
}

.notice {
  margin: 30px 0;
  padding: 22px 24px;
  background: #fff8e8;
  border-left: 5px solid var(--gold);
  border-radius: 0 var(--radius) var(--radius) 0;
}

.notice strong {
  display: block;
  margin-bottom: 5px;
  color: var(--ink);
}

.guide-shot {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
  margin: 34px 0;
}

.guide-shot figure {
  margin: 0;
}

.guide-shot img {
  width: min(100%, 300px);
  max-width: 400px;
  height: auto;
  margin: 0 auto;
  border: 9px solid var(--ink);
  border-radius: 24px;
}

.guide-shot figcaption {
  margin-top: 12px;
  color: var(--muted);
  font-size: 13px;
  text-align: center;
}

.side-nav {
  position: sticky;
  top: 102px;
  padding: 24px;
  background: var(--ink-soft);
  border-radius: var(--radius);
}

.side-nav strong {
  display: block;
  margin-bottom: 13px;
  color: var(--white);
}

.side-nav a {
  display: block;
  padding: 9px 0;
  color: #bdc9dc;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  font-size: 14px;
}

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

.side-nav .download-button {
  width: 100%;
  margin-top: 20px;
  color: var(--ink);
  border-bottom: 1px solid var(--gold);
}

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

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

.faq-question {
  width: 100%;
  display: grid;
  grid-template-columns: 48px 1fr 28px;
  align-items: center;
  gap: 12px;
  padding: 24px 0;
  color: var(--ink);
  background: transparent;
  border: 0;
  text-align: left;
  cursor: pointer;
}

.faq-question b {
  color: var(--coral);
  font-size: 13px;
}

.faq-question span:nth-child(2) {
  font-size: 18px;
  font-weight: 800;
}

.faq-icon {
  color: var(--cyan-dark);
  font-size: 24px;
  text-align: center;
  transition: transform 180ms ease;
}

.faq-question[aria-expanded="true"] .faq-icon {
  transform: rotate(45deg);
}

.faq-answer {
  padding: 0 42px 24px 60px;
}

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

.faq-answer p {
  margin: 0;
}

.feature-detail-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
  margin-bottom: 54px;
}

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

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

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

.site-footer {
  padding: 54px 0 26px;
  color: #a9b7ce;
  background: #040b18;
}

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

.footer-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--white);
  font-size: 19px;
  font-weight: 800;
}

.footer-brand img {
  width: 40px;
  height: 40px;
  border-radius: 7px;
}

.footer-grid p {
  max-width: 480px;
  margin: 16px 0 0;
  font-size: 13px;
}

.footer-links strong {
  display: block;
  margin-bottom: 12px;
  color: var(--white);
}

.footer-links a {
  display: block;
  margin: 8px 0;
  font-size: 14px;
}

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

.footer-bottom {
  padding-top: 23px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 12px;
}

.footer-bottom p {
  margin: 4px 0;
}

@media (max-width: 980px) {
  .menu-toggle {
    display: inline-flex;
  }

  .site-nav {
    position: fixed;
    top: 72px;
    right: 0;
    bottom: 0;
    width: min(330px, 88vw);
    display: flex;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 24px;
    background: var(--ink);
    box-shadow: -18px 30px 60px rgba(0, 0, 0, 0.34);
    transform: translateX(105%);
    transition: transform 200ms ease;
  }

  .site-nav.open {
    transform: translateX(0);
  }

  .site-nav a {
    padding: 15px 5px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  }

  .nav-download {
    margin-top: 18px;
    text-align: center;
  }

  .hero-layout {
    grid-template-columns: 1fr 360px;
    gap: 28px;
  }

  .phone {
    width: 190px;
  }

  .phone.front {
    right: 0;
  }

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

  .proof-grid {
    grid-template-columns: 0.7fr 1.3fr;
  }

  .proof-grid .quote:last-child {
    grid-column: 2;
  }

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

  .side-nav {
    position: static;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0 24px;
  }

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

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

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

  .site-nav {
    top: 64px;
  }

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

  .hero-layout {
    grid-template-columns: 1fr;
    padding-top: 58px;
    padding-bottom: 0;
  }

  .hero h1 {
    font-size: 42px;
  }

  .hero h1 + p,
  .page-hero p {
    font-size: 16px;
  }

  .device-stage {
    min-height: 150px;
    height: 150px;
    overflow: hidden;
    margin-top: 12px;
  }

  .phone {
    width: 178px;
  }

  .phone.front {
    right: calc(50% - 154px);
  }

  .phone.back {
    left: calc(50% - 154px);
  }

  .orbit-label {
    display: none;
  }

  .section {
    padding: 68px 0;
  }

  .section-heading {
    align-items: start;
    flex-direction: column-reverse;
    gap: 8px;
    margin-bottom: 28px;
  }

  .feature-grid,
  .screen-grid,
  .path-grid,
  .proof-grid,
  .feature-detail-grid,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .screen-grid {
    gap: 42px;
  }

  .proof-grid .quote:last-child {
    grid-column: auto;
  }

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

  .page-hero {
    padding: 70px 0 62px;
  }

  .step-item {
    grid-template-columns: 52px minmax(0, 1fr);
    gap: 16px;
  }

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

  .guide-shot {
    grid-template-columns: 1fr;
  }

  .side-nav {
    display: block;
  }

  .faq-question {
    grid-template-columns: 36px 1fr 24px;
  }

  .faq-answer {
    padding-right: 12px;
    padding-left: 48px;
  }
}

@media (max-width: 430px) {
  .brand {
    font-size: 17px;
  }

  .brand img {
    width: 37px;
    height: 37px;
  }

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

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

  .phone {
    width: 158px;
  }

  .phone.front {
    right: calc(50% - 137px);
  }

  .phone.back {
    left: calc(50% - 137px);
  }

  .orbit-label {
    right: calc(50% - 150px);
    width: 140px;
  }

  .feature-card,
  .path-link {
    padding: 24px 20px;
  }

  .path-link h3 {
    margin-top: 34px;
    font-size: 24px;
  }
}

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