:root {
  --bg: #070d18;
  --bg-soft: #0f1a2f;
  --card: #121f38;
  --text: #ecf3ff;
  --muted: #a7b8d9;
  --brand: #37c8ff;
  --brand-strong: #17a6f4;
  --border: #28406f;
  --shadow: 0 10px 40px rgba(0, 0, 0, 0.35);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at 8% 8%, rgba(31, 115, 255, 0.2), transparent 40%),
    radial-gradient(circle at 90% 10%, rgba(55, 200, 255, 0.2), transparent 35%),
    linear-gradient(160deg, var(--bg), #060a12 60%, #060d1b);
  line-height: 1.6;
}

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

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

.container {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(12px);
  background: rgba(7, 13, 24, 0.68);
  border-bottom: 1px solid rgba(40, 64, 111, 0.6);
}

.nav-wrap {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.1rem;
}

.nav-links {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 24px;
}

.nav-links a {
  color: var(--muted);
  transition: color 0.2s ease;
}

.nav-links a:hover,
.nav-links a:focus-visible {
  color: var(--text);
}

.hero {
  padding: 64px 0 56px;
}

.hero-grid {
  display: grid;
  gap: 36px;
  align-items: center;
  grid-template-columns: 1.08fr 0.92fr;
}

.eyebrow {
  display: inline-block;
  margin: 0 0 12px;
  font-size: 0.92rem;
  color: #84d9ff;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  margin: 0;
  line-height: 1.2;
}

h1 {
  font-size: clamp(2rem, 3.7vw, 3.4rem);
  margin-bottom: 14px;
}

h2 {
  text-align: center;
  font-size: clamp(1.5rem, 2.8vw, 2.2rem);
  margin-bottom: 28px;
}

.lead {
  max-width: 55ch;
  margin: 0;
  color: var(--muted);
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 26px 0 18px;
}

.btn {
  --btn-bg: linear-gradient(135deg, var(--brand), var(--brand-strong));
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 20px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-weight: 600;
  color: #041423;
  background: var(--btn-bg);
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, opacity 0.2s ease;
}

.btn:hover,
.btn:focus-visible {
  transform: translateY(-1px);
  box-shadow: 0 10px 20px rgba(55, 200, 255, 0.22);
}

.btn-small {
  min-height: 38px;
  padding: 0 16px;
  font-size: 0.9rem;
}

.btn-ghost {
  color: var(--text);
  background: transparent;
  border-color: var(--border);
}

.btn-block {
  width: 100%;
}

.hero-points {
  margin: 0;
  padding-left: 20px;
  color: #b9cae8;
}

.hero-visual {
  border-radius: 22px;
  border: 1px solid rgba(55, 200, 255, 0.25);
  overflow: hidden;
  background: rgba(14, 26, 48, 0.7);
  box-shadow: var(--shadow);
}

.section {
  padding: 56px 0;
}

.feature-grid,
.download-grid {
  display: grid;
  gap: 18px;
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.card,
.download-card {
  border-radius: 16px;
  border: 1px solid rgba(40, 64, 111, 0.75);
  background: linear-gradient(170deg, rgba(19, 33, 59, 0.86), rgba(14, 24, 42, 0.72));
  padding: 22px 20px;
}

.card h3,
.download-card h3 {
  margin-bottom: 8px;
}

.card p,
.download-card p {
  margin: 0 0 16px;
  color: var(--muted);
}

.section-dark {
  background: linear-gradient(180deg, rgba(7, 13, 24, 0.26), rgba(7, 13, 24, 0.64));
  border-top: 1px solid rgba(40, 64, 111, 0.5);
  border-bottom: 1px solid rgba(40, 64, 111, 0.5);
}

.qr-wrap {
  margin-top: 24px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--muted);
}

.faq-list {
  width: min(860px, 100%);
  margin: 0 auto;
  display: grid;
  gap: 12px;
}

.faq-item {
  border: 1px solid rgba(40, 64, 111, 0.75);
  border-radius: 12px;
  padding: 0 16px;
  background: rgba(13, 23, 40, 0.6);
}

.faq-item summary {
  cursor: pointer;
  padding: 14px 2px;
  font-weight: 600;
}

.faq-item p {
  margin: 0 2px 14px;
  color: var(--muted);
}

.site-footer {
  border-top: 1px solid rgba(40, 64, 111, 0.6);
  background: rgba(5, 10, 18, 0.7);
}

.footer-inner {
  min-height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  color: var(--muted);
}

.reveal {
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

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

@media (max-width: 980px) {
  .hero-grid {
    grid-template-columns: 1fr;
  }

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

@media (max-width: 760px) {
  .nav-links {
    display: none;
  }

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

  .hero {
    padding-top: 48px;
  }
}