:root {
  color-scheme: light;
  --bg: #f8fafc;
  --surface: #ffffff;
  --surface-soft: #eef5f8;
  --text: #13202b;
  --muted: #657482;
  --line: rgba(19, 32, 43, 0.1);
  --accent: #2f7d75;
  --accent-dark: #205d58;
  --accent-warm: #d98f58;
  --shadow: 0 24px 70px rgba(31, 49, 64, 0.14);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  overflow-x: hidden;
  background: var(--bg);
  color: var(--text);
  font-family: "Inter", "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
  letter-spacing: 0;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 72px;
  padding: 0 clamp(20px, 5vw, 72px);
  background: rgba(248, 250, 252, 0.88);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(18px);
}

.brand,
.nav-links,
.hero-stats,
.site-footer,
.app-topline,
.panel-head {
  display: flex;
  align-items: center;
}

.brand {
  gap: 10px;
  font-weight: 800;
  font-size: 18px;
}

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

.nav-links {
  gap: clamp(16px, 3vw, 34px);
  color: var(--muted);
  font-size: 14px;
}

.nav-links a:hover,
.site-footer a:hover {
  color: var(--accent);
}

.btn {
  border-radius: 8px;
  font-weight: 700;
  transition: transform 180ms ease, box-shadow 180ms ease, background 180ms ease;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 22px;
  border: 1px solid transparent;
}

.btn.primary {
  background: var(--text);
  color: #fff;
  box-shadow: 0 16px 34px rgba(19, 32, 43, 0.22);
}

.btn.secondary {
  background: rgba(255, 255, 255, 0.72);
  border-color: rgba(19, 32, 43, 0.28);
}

.btn:hover {
  transform: translateY(-2px);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(360px, 0.86fr);
  gap: clamp(36px, 6vw, 80px);
  align-items: center;
  min-height: calc(88vh - 72px);
  padding: clamp(40px, 6vw, 76px) clamp(20px, 5vw, 72px) 52px;
  border-bottom: 1px solid var(--line);
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0;
}

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

h1 {
  max-width: 820px;
  margin-bottom: 22px;
  font-size: clamp(40px, 6vw, 78px);
  line-height: 1.05;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 0;
  font-size: clamp(30px, 4vw, 48px);
  line-height: 1.16;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 12px;
  font-size: 20px;
}

.hero-lede {
  max-width: 680px;
  margin-bottom: 28px;
  color: var(--muted);
  font-size: 18px;
  line-height: 1.8;
}

.hero-stats {
  flex-wrap: wrap;
  gap: 18px;
  margin: 0;
}

.hero-stats div {
  min-width: 132px;
  padding: 16px 18px;
  background: rgba(255, 255, 255, 0.66);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.hero-stats dt {
  font-size: 24px;
  font-weight: 850;
}

.hero-stats dd {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.product-preview {
  position: relative;
  min-height: 540px;
  width: 100%;
  overflow: visible;
}

.phone-shell {
  position: relative;
  z-index: 2;
  width: min(100%, 360px);
  min-height: 580px;
  margin-left: auto;
  padding: 22px;
  background: #101820;
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 34px;
  box-shadow: var(--shadow);
  color: #f8fafc;
}

.phone-bar {
  width: 88px;
  height: 5px;
  margin: 0 auto 28px;
  background: rgba(255, 255, 255, 0.28);
  border-radius: 999px;
}

.app-topline {
  justify-content: space-between;
  margin-bottom: 24px;
  font-weight: 750;
}

.app-topline span:last-child {
  color: #90d3c8;
  font-size: 13px;
}

.chat-card {
  margin-bottom: 14px;
  padding: 18px;
  border-radius: 8px;
  line-height: 1.6;
}

.chat-card p {
  margin: 8px 0 0;
  color: rgba(255, 255, 255, 0.74);
  font-size: 14px;
}

.chat-card.assistant {
  background: rgba(47, 125, 117, 0.32);
}

.chat-card.user {
  margin-left: 34px;
  background: rgba(217, 143, 88, 0.28);
}

.mini-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-top: 28px;
}

.mini-grid span {
  min-height: 86px;
  padding: 16px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 8px;
  font-weight: 750;
}

.desktop-panel {
  position: absolute;
  right: 140px;
  bottom: 18px;
  z-index: 3;
  width: min(92vw, 430px);
  padding: 18px;
  background: rgba(255, 255, 255, 0.88);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(12px);
}

.panel-head {
  gap: 7px;
  margin-bottom: 18px;
}

.panel-head span {
  width: 10px;
  height: 10px;
  background: #b9c4cc;
  border-radius: 999px;
}

.panel-content {
  display: grid;
  gap: 10px;
}

.panel-content div {
  padding: 14px;
  background: var(--surface-soft);
  border-radius: 8px;
}

.panel-content small {
  display: block;
  margin-bottom: 5px;
  color: var(--muted);
}

.section {
  padding: clamp(48px, 7vw, 84px) clamp(20px, 5vw, 72px);
  border-bottom: 1px solid var(--line);
}

.section-heading {
  max-width: 760px;
  margin-bottom: 28px;
}

.feature-grid,
.platform-grid,
.download-grid {
  display: grid;
  gap: 18px;
}

.feature-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  max-width: 1040px;
}

.feature-card,
.platform-grid article,
.download-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.feature-card {
  padding: 26px;
}

.feature-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  margin-bottom: 24px;
  background: var(--surface-soft);
  color: var(--accent-dark);
  border-radius: 8px;
  font-size: 13px;
  font-weight: 850;
}

.feature-card p,
.platform-grid p,
.pwa-copy p,
.release-note {
  color: var(--muted);
  line-height: 1.75;
}

.platform-section {
  background: #eef5f8;
}

.platform-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.platform-grid article {
  padding: 24px;
  min-height: 180px;
}

.pwa-section {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(320px, 1fr);
  gap: clamp(24px, 4vw, 48px);
  align-items: start;
  background: var(--surface);
}

.pwa-copy {
  max-width: 620px;
}

.pwa-guide {
  min-width: 0;
  overflow: hidden;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.pwa-guide-trigger {
  display: grid;
  place-items: center;
  width: 100%;
  min-width: 0;
  padding: 12px;
  background: #f8fafc;
  border: 0;
  cursor: zoom-in;
  appearance: none;
  -webkit-appearance: none;
}

.pwa-guide img {
  display: block;
  width: auto;
  max-width: 100%;
  max-height: 460px;
  height: auto;
  object-fit: contain;
}

.image-lightbox[hidden] {
  display: none;
}

.image-lightbox {
  position: fixed;
  inset: 0;
  z-index: 40;
  display: grid;
  place-items: center;
}

.image-lightbox-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(8, 15, 22, 0.76);
  border: 0;
}

.image-lightbox-dialog {
  position: relative;
  z-index: 1;
  width: min(92vw, 980px);
  max-height: 92vh;
  padding: 18px;
  background: rgba(255, 255, 255, 0.96);
  border: 1px solid rgba(255, 255, 255, 0.24);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.image-lightbox-close {
  position: absolute;
  top: 12px;
  right: 12px;
  min-height: 40px;
  padding: 0 14px;
  background: rgba(19, 32, 43, 0.88);
  color: #fff;
  border: 0;
  border-radius: 999px;
  cursor: pointer;
}

.image-lightbox-image {
  display: block;
  width: 100%;
  max-height: calc(92vh - 36px);
  height: auto;
  margin: 0 auto;
  object-fit: contain;
}

.download-grid {
  grid-template-columns: 1.1fr 1fr 1fr;
}

.download-card {
  display: grid;
  gap: 10px;
  min-height: 164px;
  padding: 24px;
}

.download-card span {
  color: var(--muted);
  font-size: 14px;
}

.download-card strong {
  font-size: 25px;
}

.download-card small {
  color: var(--muted);
  line-height: 1.6;
}

.download-card.highlight {
  background: var(--text);
  color: #fff;
  border-color: var(--text);
}

.download-card.highlight span,
.download-card.highlight small {
  color: rgba(255, 255, 255, 0.78);
}

.download-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 18px 42px rgba(31, 49, 64, 0.1);
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 500ms ease, transform 500ms ease;
}

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

.release-note {
  max-width: 820px;
  margin: 24px 0 0;
  font-size: 14px;
}

.site-footer {
  justify-content: space-between;
  gap: 18px;
  padding: 30px clamp(20px, 5vw, 72px);
  color: var(--muted);
}

.site-footer div {
  display: grid;
  gap: 4px;
}

.site-footer strong {
  color: var(--text);
}

@media (max-width: 980px) {
  .site-header {
    min-height: auto;
    padding-top: 16px;
    padding-bottom: 16px;
    flex-wrap: wrap;
  }

  .nav-links {
    order: 3;
    width: 100%;
    overflow-x: auto;
    padding-bottom: 2px;
  }

  .hero,
  .pwa-section {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

  .product-preview {
    display: grid;
    gap: 18px;
    min-height: 0;
  }

  .phone-shell {
    margin: 0 auto;
  }

  .desktop-panel {
    position: static;
    width: min(100%, 430px);
    margin: 0 auto;
    transform: none;
  }

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

@media (max-width: 640px) {
  .site-header {
    gap: 14px;
  }

  .hero {
    padding-top: 34px;
    padding-bottom: 38px;
  }

  .hero-stats {
    display: grid;
    grid-template-columns: 1fr;
  }

  .product-preview {
    gap: 14px;
    min-height: 0;
  }

  .phone-shell {
    width: 100%;
    min-height: auto;
    padding: 18px;
    border-radius: 28px;
  }

  .desktop-panel {
    width: min(82vw, 280px);
    padding: 10px;
  }

  .panel-head {
    gap: 5px;
    margin-bottom: 10px;
  }

  .panel-head span {
    width: 8px;
    height: 8px;
  }

  .panel-content {
    gap: 8px;
  }

  .panel-content div {
    padding: 10px 12px;
  }

  .panel-content small {
    margin-bottom: 4px;
    font-size: 11px;
  }

  .panel-content strong {
    font-size: 13px;
    line-height: 1.45;
  }

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

  .pwa-guide {
    max-width: 100%;
  }

  .pwa-guide-trigger {
    width: 100%;
  }

  .pwa-guide img {
    width: 100%;
    max-width: 100%;
    height: auto;
    max-height: none;
  }

  .platform-grid article,
  .download-card {
    min-height: auto;
  }

  .site-footer {
    align-items: flex-start;
    flex-direction: column;
  }
}