@import url("https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&family=Noto+Serif+SC:wght@500;600;700;800&display=swap");

:root {
  --ink: #17252b;
  --muted: #687780;
  --line: #d9e1e5;
  --paper: #f4f6f7;
  --panel: #ffffff;
  --soft: #edf3f2;
  --accent: #0b806b;
  --accent-dark: #075c51;
  --blue: #2f6aa8;
  --shadow: 0 18px 48px rgba(20, 37, 43, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  color: var(--ink);
  background: var(--paper);
  font-family: "Inter", "PingFang SC", "Microsoft YaHei", "Segoe UI", Arial, sans-serif;
  letter-spacing: 0;
}

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

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

.section-shell {
  width: min(1180px, calc(100% - 48px));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  width: 100%;
  padding: 0;
  border-bottom: 1px solid transparent;
  background: rgba(244, 246, 247, 0.92);
  backdrop-filter: blur(16px);
  transition: border-color 0.25s ease, box-shadow 0.25s ease;
}

.site-header.is-elevated {
  border-bottom-color: var(--line);
  box-shadow: 0 8px 22px rgba(20, 37, 43, 0.06);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  padding-top: 18px;
  padding-bottom: 18px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-width: max-content;
  font-family: "Inter", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 20px;
  font-weight: 800;
}

.brand img {
  width: 36px;
  height: 36px;
}

.nav-links {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  flex-wrap: wrap;
}

.nav-links a {
  padding: 9px 13px;
  color: var(--muted);
  font-family: "Inter", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 14px;
  font-weight: 600;
  transition: color 0.2s ease, background 0.2s ease;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--ink);
  background: var(--soft);
}

.header-action,
.primary-button,
.ghost-button,
.download-button,
.tiny-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 6px;
  font-family: "Inter", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-weight: 700;
  transition: color 0.2s ease, background 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

.header-action,
.primary-button,
.download-button {
  color: #ffffff;
  background: var(--accent);
}

.header-action:hover,
.primary-button:hover,
.download-button:hover,
.tiny-button:hover {
  background: var(--accent-dark);
  transform: translateY(-1px);
}

.ghost-button,
.tiny-button {
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--ink);
}

.ghost-button:hover {
  border-color: #b8c7c7;
  background: var(--soft);
}

.eyebrow {
  margin: 0 0 13px;
  color: var(--accent-dark);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

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

h1 {
  max-width: 780px;
  margin-bottom: 22px;
  font-family: "Noto Serif SC", "Songti SC", "STSong", "SimSun", serif;
  font-size: clamp(48px, 6.4vw, 76px);
  line-height: 1.02;
  font-weight: 800;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 15px;
  font-family: "Noto Serif SC", "Songti SC", "STSong", "SimSun", serif;
  font-size: clamp(32px, 4vw, 52px);
  line-height: 1.1;
  font-weight: 700;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 9px;
  font-family: "Noto Serif SC", "Songti SC", "STSong", "SimSun", serif;
  font-size: 20px;
  font-weight: 700;
}

.hero {
  position: relative;
  isolation: isolate;
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(480px, 1.08fr);
  align-items: center;
  gap: 74px;
  min-height: calc(100vh - 74px);
  padding: 78px 0 88px;
}

.hero::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  z-index: -1;
  width: 100vw;
  transform: translateX(-50%);
  background:
    linear-gradient(90deg, rgba(244, 246, 247, 0.94) 0%, rgba(244, 246, 247, 0.88) 46%, rgba(244, 246, 247, 0.42) 100%),
    url("hero-bg-abstract.png") center/cover no-repeat;
}

.hero-subtitle,
.section-heading > p:last-child,
.download-copy > p,
.support-copy > p {
  color: var(--muted);
  font-size: 17px;
  line-height: 1.8;
}

.hero-subtitle {
  max-width: 650px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 32px 0 0;
}

.hero-meta {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  max-width: 620px;
  margin-top: 42px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}

.hero-meta div {
  padding-right: 18px;
}

.hero-meta div + div {
  padding-left: 18px;
  border-left: 1px solid var(--line);
}

.hero-meta strong {
  display: block;
  margin-bottom: 4px;
  font-size: 24px;
}

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

.app-window {
  overflow: hidden;
  border: 1px solid #cbd6d9;
  border-radius: 10px;
  background: var(--panel);
  box-shadow: var(--shadow);
}

.window-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 50px;
  padding: 0 18px;
  border-bottom: 1px solid var(--line);
  background: #ffffff;
  color: var(--muted);
  font-size: 12px;
}

.window-bar strong {
  color: var(--ink);
  font-size: 13px;
}

.window-dots {
  display: flex;
  gap: 6px;
}

.window-dots i {
  display: block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #c8d2d5;
}

.window-dots i:first-child {
  background: #c78175;
}

.window-chip {
  padding: 5px 8px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: #f8fafb;
}

.window-body {
  display: grid;
  grid-template-columns: 124px minmax(0, 1fr);
  min-height: 430px;
}

.window-sidebar {
  padding: 20px 12px;
  border-right: 1px solid var(--line);
  background: #f7f9fa;
}

.sidebar-item {
  display: block;
  margin-bottom: 5px;
  padding: 10px 12px;
  border-radius: 5px;
  color: var(--muted);
  font-size: 13px;
}

.sidebar-item.active {
  background: var(--soft);
  color: var(--accent-dark);
  font-weight: 800;
}

.window-content {
  min-width: 0;
  padding: 22px;
  background: #ffffff;
}

.status-panel,
.window-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.status-panel p,
.window-footer span {
  margin-bottom: 5px;
  color: var(--muted);
  font-size: 12px;
}

.status-panel strong,
.window-footer strong {
  font-size: 18px;
}

.status-badge {
  padding: 7px 9px;
  border-radius: 4px;
  font-size: 12px;
  font-weight: 800;
}

.status-badge.connected {
  background: #e6f3ef;
  color: var(--accent-dark);
}

.signal-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
  margin: 22px 0;
}

.signal-row div {
  padding: 12px;
  border: 1px solid var(--line);
  background: #fafcfc;
}

.signal-row span {
  display: block;
  margin-bottom: 5px;
  color: var(--muted);
  font-size: 11px;
}

.signal-row strong {
  font-size: 15px;
}

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

.node-row {
  display: grid;
  grid-template-columns: 100px minmax(80px, 1fr) 56px;
  align-items: center;
  gap: 12px;
  padding: 15px 0;
  border-bottom: 1px solid var(--line);
  font-size: 12px;
}

.node-row > span {
  color: var(--muted);
}

.node-row strong {
  color: var(--accent-dark);
  font-size: 11px;
  text-align: right;
}

.node-track {
  height: 5px;
  overflow: hidden;
  border-radius: 4px;
  background: #e8eef0;
}

.node-track i {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: var(--accent);
}

.window-footer {
  padding-top: 18px;
}

.window-footer strong {
  font-size: 13px;
}

.tiny-button {
  min-height: 34px;
  padding: 0 12px;
  font-size: 12px;
}

.platform-strip {
  border-block: 1px solid var(--line);
  background: #ffffff;
}

.platform-strip-inner {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
  padding: 21px 0;
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
  text-align: center;
}

.coverage-band {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  color: #ffffff;
  background:
    linear-gradient(90deg, rgba(5, 14, 29, 0.92) 0%, rgba(6, 34, 53, 0.78) 55%, rgba(8, 42, 68, 0.54) 100%),
    url("global-map-bg.png") center/cover no-repeat;
}

.coverage-band::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.03), rgba(0, 0, 0, 0.12));
}

.coverage-inner {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 42px;
  min-height: 430px;
  padding: 84px 0;
}

.coverage-inner > div {
  max-width: 670px;
}

.coverage-inner .eyebrow {
  color: #a9e4d8;
}

.coverage-inner h2 {
  max-width: 640px;
  color: #ffffff;
}

.coverage-inner p:not(.eyebrow) {
  margin-bottom: 0;
  color: rgba(255, 255, 255, 0.76);
  font-size: 16px;
  line-height: 1.85;
}

.coverage-inner .primary-button {
  flex: 0 0 auto;
  background: #ffffff;
  color: #0a5d52;
}

.coverage-inner .primary-button:hover {
  background: #dff5ee;
}

.feature-section,
.compare-section,
.platform-section,
.install-section,
.faq-section,
.support-section {
  padding: 112px 0;
}

.section-heading {
  max-width: 760px;
  margin-bottom: 38px;
}

.feature-grid,
.download-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.feature-card,
.download-card,
.compare-card,
.install-card,
.status-card,
.release-box {
  border: 1px solid var(--line);
  background: var(--panel);
}

.feature-card,
.download-card {
  transition: border-color 0.25s ease, box-shadow 0.25s ease, transform 0.25s ease;
}

.feature-card:hover,
.download-card:hover {
  border-color: #b7cbc8;
  box-shadow: 0 16px 34px rgba(20, 37, 43, 0.09);
  transform: translateY(-4px);
}

.feature-card {
  min-height: 230px;
  padding: 26px;
}

.feature-card p,
.download-card p,
.download-card li,
.status-card > p:last-child {
  color: var(--muted);
  line-height: 1.7;
}

.feature-icon {
  display: inline-grid;
  place-items: center;
  width: 48px;
  height: 48px;
  margin-bottom: 34px;
  border: 1px solid #bdd5d0;
  border-radius: 6px;
  background-color: var(--soft);
  background-position: center;
  background-repeat: no-repeat;
  background-size: 28px 28px;
}

.icon-route {
  background-image: url("icons/route.svg");
}

.icon-speed {
  background-image: url("icons/speed.svg");
}

.icon-devices {
  background-image: url("icons/devices.svg");
}

.icon-shield {
  background-image: url("icons/shield.svg");
}

.compare-section {
  border-top: 1px solid var(--line);
}

.compare-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.compare-card {
  padding: 30px;
}

.timeline {
  position: relative;
  margin-top: 26px;
}

.timeline::before {
  content: "";
  position: absolute;
  top: 14px;
  bottom: 14px;
  left: 14px;
  width: 1px;
  background: var(--line);
}

.timeline div {
  position: relative;
  display: flex;
  align-items: center;
  gap: 18px;
  min-height: 58px;
}

.timeline span {
  position: relative;
  z-index: 1;
  display: grid;
  place-items: center;
  width: 29px;
  height: 29px;
  border: 1px solid #b9ceca;
  border-radius: 50%;
  background: #ffffff;
  color: var(--accent-dark);
  font-size: 12px;
  font-weight: 800;
}

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

.scenario-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

.scenario-list li {
  padding: 17px 0;
  border-bottom: 1px solid var(--line);
  color: var(--muted);
  font-size: 14px;
}

.scenario-list li:nth-child(odd) {
  margin-right: 18px;
}

.scenario-list li::before {
  content: "—";
  margin-right: 8px;
  color: var(--accent);
}

.support-section {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 36px;
  border-top: 1px solid var(--line);
}

.support-copy {
  max-width: 740px;
}

.download-hero {
  position: relative;
  isolation: isolate;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 0.64fr);
  align-items: center;
  gap: 70px;
  padding: 84px 0 70px;
}

.download-hero::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  z-index: -1;
  width: 100vw;
  transform: translateX(-50%);
  background:
    linear-gradient(180deg, rgba(244, 246, 247, 0.92) 0%, rgba(244, 246, 247, 0.82) 100%),
    url("devices-bg.png") center/cover no-repeat;
}

.download-copy h1 {
  max-width: 760px;
}

.release-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 28px;
}

.release-tags span {
  padding: 8px 10px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: #ffffff;
  color: var(--muted);
  font-size: 12px;
}

.release-box {
  padding: 28px;
  border-color: #1d3238;
  background: #1d3238;
  color: #ffffff;
}

.release-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 20px;
  padding-bottom: 20px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.16);
}

.release-head span {
  color: #a9c2bd;
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.release-head strong {
  font-size: 30px;
}

.release-list {
  display: grid;
  gap: 13px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
}

.release-list li {
  color: #d4e0de;
  font-size: 13px;
  line-height: 1.6;
}

.release-list li::before {
  content: "✓";
  margin-right: 8px;
  color: #73c0ae;
}

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

.download-card {
  display: flex;
  min-height: 320px;
  flex-direction: column;
  padding: 26px;
}

.download-card-top {
  display: flex;
  align-items: center;
  gap: 16px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--line);
}

.platform-icon {
  display: grid;
  flex: 0 0 auto;
  place-items: center;
  width: 54px;
  height: 54px;
  border: 1px solid #c2d4d2;
  border-radius: 5px;
  background-color: var(--soft);
  background-position: center;
  background-repeat: no-repeat;
  background-size: 28px 28px;
}

.icon-win {
  background-image: url("icons/desktop.svg");
}

.icon-mac {
  background-image: url("icons/laptop.svg");
}

.icon-ios {
  background-image: url("icons/tablet.svg");
}

.icon-android {
  background-image: url("icons/mobile.svg");
}

.download-card h3 {
  margin-bottom: 4px;
}

.download-card-top p {
  margin: 0;
  font-size: 12px;
}

.download-card ul {
  display: grid;
  gap: 8px;
  flex: 1;
  margin: 20px 0;
  padding: 0;
  list-style: none;
}

.download-card li {
  font-size: 13px;
}

.download-card li::before {
  content: "·";
  margin-right: 8px;
  color: var(--accent);
  font-weight: 900;
}

.download-button {
  width: max-content;
  min-width: 116px;
}

.install-section {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(260px, 0.65fr);
  gap: 16px;
}

.install-card,
.status-card {
  padding: 30px;
}

.check-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  margin-top: 28px;
}

.check-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
}

.check-item span {
  display: grid;
  flex: 0 0 auto;
  place-items: center;
  width: 28px;
  height: 28px;
  border: 1px solid #bad0cb;
  border-radius: 50%;
  color: var(--accent-dark);
  font-size: 12px;
  font-weight: 800;
}

.check-item p {
  margin: 3px 0 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.7;
}

.status-card {
  background: #e8f1ef;
}

.status-card .eyebrow {
  margin-bottom: 18px;
}

.status-card strong {
  display: block;
  margin-bottom: 12px;
  color: var(--accent-dark);
  font-size: 21px;
}

.faq-list {
  display: grid;
  gap: 10px;
}

details {
  border: 1px solid var(--line);
  background: #ffffff;
}

summary {
  cursor: pointer;
  padding: 21px 24px;
  font-size: 15px;
  font-weight: 800;
}

details p {
  margin: 0;
  padding: 0 24px 22px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

.site-footer {
  border-top: 1px solid var(--line);
  background: #ffffff;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 28px 0;
  color: var(--muted);
}

.footer-inner p {
  margin: 0;
  font-size: 12px;
}

.reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

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

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

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

@media (max-width: 980px) {
  .header-inner {
    align-items: flex-start;
    flex-wrap: wrap;
  }

  .nav-links {
    order: 3;
    width: 100%;
    justify-content: flex-start;
  }

  .hero,
  .download-hero {
    grid-template-columns: 1fr;
    gap: 42px;
  }

  .coverage-inner {
    align-items: flex-start;
    flex-direction: column;
  }

  .hero {
    min-height: auto;
  }

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

  .compare-grid,
  .install-section {
    grid-template-columns: 1fr;
  }

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

@media (max-width: 640px) {
  .section-shell {
    width: min(100% - 28px, 1180px);
  }

  .header-inner {
    padding-top: 14px;
    padding-bottom: 14px;
  }

  .header-action {
    display: none;
  }

  .nav-links a {
    padding: 8px 9px;
    font-size: 13px;
  }

  .hero,
  .download-hero {
    padding: 54px 0 64px;
  }

  h1 {
    font-size: clamp(43px, 14vw, 64px);
  }

  .hero-subtitle,
  .section-heading > p:last-child,
  .download-copy > p,
  .support-copy > p {
    font-size: 15px;
  }

  .hero-actions,
  .support-section,
  .footer-inner,
  .coverage-inner {
    align-items: stretch;
    flex-direction: column;
  }

  .primary-button,
  .ghost-button {
    width: 100%;
  }

  .hero-meta {
    gap: 12px;
  }

  .hero-meta div {
    padding-right: 0;
  }

  .hero-meta div + div {
    padding-left: 0;
    border-left: 0;
  }

  .platform-strip-inner {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px 8px;
    font-size: 12px;
  }

  .window-body {
    grid-template-columns: 90px minmax(0, 1fr);
  }

  .window-content {
    padding: 16px;
  }

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

  .node-row {
    grid-template-columns: 80px minmax(60px, 1fr) 48px;
    gap: 8px;
  }

  .feature-section,
  .compare-section,
  .platform-section,
  .install-section,
  .faq-section,
  .support-section {
    padding: 70px 0;
  }

  .coverage-inner {
    min-height: 390px;
    padding: 72px 0;
  }

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

  .scenario-list {
    grid-template-columns: 1fr;
  }

  .scenario-list li:nth-child(odd) {
    margin-right: 0;
  }

  .download-button {
    width: 100%;
  }
}