:root {
  --bg: #f4f7fe;
  --surface: #ffffff;
  --text: #1f2430;
  --muted: #646c7a;
  --primary: #3d7cff;
  --primary-dark: #2d65d8;
  --border: #e7ebf3;
  --radius: 14px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC",
    "Microsoft YaHei", sans-serif;
  background: radial-gradient(circle at top, #eaf0ff 0%, var(--bg) 34%);
  color: var(--text);
  line-height: 1.6;
}

.container {
  width: min(1120px, 92vw);
  margin: 0 auto;
}

.topbar {
  position: sticky;
  top: 0;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  z-index: 50;
}

.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
}

.brand {
  text-decoration: none;
  color: var(--text);
  font-size: 20px;
  font-weight: 700;
}

.nav {
  display: flex;
  gap: 20px;
}

.nav a {
  text-decoration: none;
  color: var(--muted);
  font-weight: 600;
}

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

.lang-btn {
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  border-radius: 999px;
  padding: 8px 14px;
  cursor: pointer;
  font-weight: 600;
}

.hero {
  padding: 64px 0 48px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 28px;
  align-items: stretch;
}

.badge {
  display: inline-block;
  border-radius: 999px;
  background: #eaf0ff;
  color: var(--primary);
  font-size: 13px;
  font-weight: 700;
  padding: 4px 12px;
  margin: 0 0 14px;
}

h1 {
  font-size: clamp(30px, 5vw, 48px);
  line-height: 1.15;
  margin: 0 0 12px;
}

.hero-desc {
  color: var(--muted);
  margin: 0 0 20px;
  max-width: 56ch;
}

.hero-metrics {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
  margin-top: 18px;
}

.hero-metrics div {
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px 12px;
}

.hero-metrics strong {
  display: block;
  font-size: 18px;
}

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

.hero-cta {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 16px;
  border-radius: 10px;
  text-decoration: none;
  font-weight: 700;
}

.btn-primary {
  color: #fff;
  background: var(--primary);
}

.btn-primary:hover {
  background: var(--primary-dark);
}

.btn-secondary {
  color: var(--text);
  border: 1px solid var(--border);
  background: #fff;
}

.hero-card,
.feature-card,
.download-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.phone-preview {
  display: flex;
  align-items: center;
  justify-content: center;
}

.phone-screen {
  width: min(320px, 90%);
  min-height: 500px;
  background: linear-gradient(175deg, #11192d, #203c82 60%, #4b75d6);
  border-radius: 28px;
  border: 1px solid #2f4f99;
  padding: 18px;
  color: #fff;
  position: relative;
  box-shadow: 0 24px 44px rgba(21, 41, 89, 0.3);
}

.phone-notch {
  width: 120px;
  height: 24px;
  border-radius: 999px;
  background: #0f1b37;
  margin: 2px auto 20px;
}

.phone-title {
  margin: 18px 0 8px;
  font-size: 20px;
  font-weight: 700;
}

.phone-snippet {
  margin: 0;
  color: rgba(255, 255, 255, 0.88);
}

.phone-tags {
  margin-top: 22px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.phone-tags span {
  border-radius: 999px;
  font-size: 12px;
  background: rgba(255, 255, 255, 0.2);
  padding: 4px 10px;
}

.section {
  padding: 56px 0;
}

.section-alt {
  background: #eef3ff;
}

h2 {
  margin: 0 0 10px;
  font-size: clamp(24px, 3vw, 36px);
}

.section-desc {
  margin: 0 0 20px;
  color: var(--muted);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.feature-card {
  padding: 18px;
}

.feature-card h3 {
  margin: 0 0 6px;
  font-size: 18px;
}

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

.download-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.download-card {
  text-decoration: none;
  color: inherit;
  padding: 18px;
}

.download-card h3 {
  margin: 0 0 4px;
}

.download-card p {
  margin: 0;
  color: var(--muted);
}

.download-card:hover {
  border-color: var(--primary);
}

.phone-carousel {
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr) 48px;
  align-items: center;
  gap: 12px;
}

.carousel-viewport {
  overflow: hidden;
  border-radius: 24px;
}

.carousel-track {
  display: flex;
  transition: transform 360ms ease;
  will-change: transform;
}

.carousel-slide {
  min-width: 100%;
  margin: 0;
  text-align: center;
}

.phone-shell {
  margin: 0 auto;
  width: min(320px, 74vw);
  border-radius: 34px;
  background: linear-gradient(180deg, #1c2640 0%, #111827 100%);
  padding: 12px;
  border: 1px solid #2b3b63;
  box-shadow: 0 18px 36px rgba(18, 30, 56, 0.24);
}

.phone-shell img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 24px;
  background: #eff3f8;
}

.carousel-slide figcaption {
  margin-top: 10px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 600;
}

.carousel-btn {
  border: 1px solid var(--border);
  background: #fff;
  color: #4a556f;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  font-size: 30px;
  line-height: 1;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.carousel-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.carousel-dots {
  margin-top: 14px;
  display: flex;
  justify-content: center;
  gap: 8px;
}

.carousel-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  border: 0;
  background: #cad1e2;
  cursor: pointer;
  padding: 0;
}

.carousel-dot.active {
  width: 20px;
  border-radius: 999px;
  background: var(--primary);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.timeline {
  display: grid;
  gap: 12px;
}

.timeline-item {
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  background: #fff;
}

.timeline-item h3 {
  margin: 0 0 6px;
}

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

details {
  border: 1px solid var(--border);
  background: #fff;
  border-radius: 10px;
  padding: 10px 14px;
}

details + details {
  margin-top: 10px;
}

summary {
  cursor: pointer;
  font-weight: 600;
}

details p {
  margin: 8px 0 0;
  color: var(--muted);
}

.contact-card {
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  background: #fff;
  margin-bottom: 16px;
}

.contact-card h3 {
  margin: 0 0 6px;
}

.contact-card p {
  margin: 0 0 12px;
  color: var(--muted);
}

.meta-links {
  display: flex;
  gap: 16px;
}

.meta-links a {
  color: var(--primary);
  text-decoration: none;
  font-weight: 600;
}

.footer {
  border-top: 1px solid var(--border);
  padding: 22px 0 32px;
  color: var(--muted);
}

.footer p {
  margin: 4px 0;
}

.icp a {
  color: var(--muted);
  text-decoration: none;
}

.icp a:hover {
  color: var(--primary);
}

@media (max-width: 880px) {
  .hero-grid,
  .feature-grid,
  .download-grid {
    grid-template-columns: 1fr;
  }

  .topbar-inner {
    flex-wrap: wrap;
    gap: 10px;
    padding: 10px 0;
  }

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

  .phone-carousel {
    grid-template-columns: 36px minmax(0, 1fr) 36px;
    gap: 8px;
  }

  .carousel-btn {
    width: 34px;
    height: 34px;
    font-size: 24px;
  }
}