:root {
  --bg-top: #0b1626;
  --bg-bottom: #13263f;
  --surface: rgba(250, 252, 255, 0.9);
  --surface-strong: #f9fbfe;
  --surface-line: rgba(148, 163, 184, 0.18);
  --text: #d9e4f2;
  --text-strong: #f8fbff;
  --text-muted: rgba(217, 228, 242, 0.72);
  --panel-text: #112033;
  --panel-muted: #5c6b81;
  --accent: #8fb5ff;
  --accent-strong: #d4ab56;
  --accent-deep: #214c85;
  --success: #8dd2b8;
  --shadow-lg: 0 32px 80px rgba(2, 8, 23, 0.28);
  --shadow-md: 0 22px 44px rgba(7, 20, 38, 0.18);
  --shadow-sm: 0 10px 24px rgba(7, 20, 38, 0.1);
  --radius-xl: 28px;
  --radius-lg: 22px;
  --radius-md: 16px;
  --content-width: 1180px;
  --transition: 220ms ease;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "MiSans", "HarmonyOS Sans SC", "Source Han Sans SC", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(143, 181, 255, 0.22), transparent 28%),
    radial-gradient(circle at 82% 18%, rgba(212, 171, 86, 0.15), transparent 24%),
    linear-gradient(180deg, var(--bg-top) 0%, var(--bg-bottom) 100%);
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.04) 1px, transparent 1px);
  background-size: 72px 72px;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.85), transparent 95%);
  pointer-events: none;
}

.page-shell {
  position: relative;
  width: min(calc(100% - 48px), var(--content-width));
  margin: 0 auto;
  padding: 24px 0 72px;
}

.topbar,
.hero,
.trust-grid,
.install-section,
.faq-section {
  animation: fade-up 680ms ease both;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 12px 0 28px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  color: inherit;
  text-decoration: none;
}

.brand-mark {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  border-radius: 18px;
  background: linear-gradient(135deg, rgba(143, 181, 255, 0.24), rgba(212, 171, 86, 0.18));
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.24), var(--shadow-sm);
  overflow: hidden;
}

.brand-mark::after {
  content: "L3";
  position: absolute;
  font-size: 16px;
  font-weight: 800;
  letter-spacing: 0.08em;
  color: rgba(255, 255, 255, 0.9);
}

.brand-mark img {
  position: relative;
  z-index: 1;
  width: 44px;
  height: 44px;
}

.brand-copy {
  display: inline-flex;
  flex-direction: column;
  gap: 4px;
}

.brand-copy strong {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-strong);
}

.brand-copy span {
  font-size: 0.88rem;
  color: var(--text-muted);
}

.topbar-meta {
  display: flex;
  align-items: center;
}

.version-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 14px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.06);
  color: var(--text);
  font-size: 0.92rem;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(320px, 0.9fr);
  gap: 28px;
  align-items: stretch;
  padding: 18px 0 44px;
}

.hero-copy,
.download-card,
.feature-card,
.step-card,
.faq-item {
  border: 1px solid var(--surface-line);
  backdrop-filter: blur(20px);
}

.hero-copy {
  padding: 44px;
  border-radius: 34px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.08), rgba(255, 255, 255, 0.04)),
    radial-gradient(circle at top left, rgba(143, 181, 255, 0.2), transparent 36%);
  box-shadow: var(--shadow-lg);
}

.eyebrow,
.section-label,
.card-label {
  margin: 0 0 14px;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent-strong);
}

.hero-copy h1,
.section-heading h2 {
  margin: 0;
  font-weight: 800;
  letter-spacing: -0.03em;
}

.hero-copy h1 {
  max-width: 12ch;
  font-size: clamp(2.7rem, 5.4vw, 4.7rem);
  line-height: 1.02;
  color: var(--text-strong);
}

.hero-lead,
.hero-sub,
.section-heading p,
.download-note p {
  margin: 0;
  line-height: 1.8;
}

.hero-lead {
  margin-top: 26px;
  max-width: 62ch;
  font-size: 1.04rem;
  color: var(--text);
}

.hero-sub {
  margin-top: 16px;
  max-width: 62ch;
  color: var(--text-muted);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 30px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 54px;
  padding: 0 24px;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 700;
  transition:
    transform var(--transition),
    box-shadow var(--transition),
    background-color var(--transition),
    border-color var(--transition),
    color var(--transition);
}

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

.button-primary {
  color: #0c1627;
  background: linear-gradient(135deg, #d7e7ff 0%, #d8b36a 100%);
  box-shadow: 0 16px 32px rgba(212, 171, 86, 0.2);
}

.button-primary:hover {
  box-shadow: 0 22px 42px rgba(212, 171, 86, 0.28);
}

.button-secondary {
  color: var(--text-strong);
  border: 1px solid rgba(255, 255, 255, 0.12);
  background: rgba(255, 255, 255, 0.04);
}

.button-secondary:hover {
  background: rgba(255, 255, 255, 0.08);
}

.button.is-disabled,
.button[aria-disabled="true"] {
  cursor: not-allowed;
  pointer-events: none;
  color: rgba(12, 22, 39, 0.48);
  background: linear-gradient(135deg, #d8dee8, #c5ccd9);
  box-shadow: none;
}

.download-note {
  display: grid;
  gap: 12px;
  margin-top: 26px;
}

.mode-badge {
  display: inline-flex;
  align-items: center;
  width: fit-content;
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(141, 210, 184, 0.12);
  border: 1px solid rgba(141, 210, 184, 0.22);
  color: #c5f3e2;
  font-size: 0.9rem;
  font-weight: 700;
}

.download-card {
  padding: 34px 30px;
  border-radius: 30px;
  background:
    linear-gradient(180deg, rgba(249, 251, 254, 0.98), rgba(242, 246, 252, 0.94)),
    radial-gradient(circle at top right, rgba(212, 171, 86, 0.16), transparent 28%);
  color: var(--panel-text);
  box-shadow: var(--shadow-md);
}

.card-header h2 {
  margin: 0;
  font-size: 1.85rem;
  line-height: 1.1;
}

.package-meta {
  margin: 28px 0 0;
  display: grid;
  gap: 18px;
}

.package-meta div {
  display: grid;
  gap: 6px;
  padding-bottom: 16px;
  border-bottom: 1px solid rgba(17, 32, 51, 0.08);
}

.package-meta dt {
  color: var(--panel-muted);
  font-size: 0.88rem;
}

.package-meta dd {
  margin: 0;
  font-size: 1.02rem;
  font-weight: 700;
}

.mono {
  font-family: "Cascadia Mono", "Consolas", monospace;
  word-break: break-all;
}

.card-status {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-top: 24px;
  padding: 12px 14px;
  border-radius: 14px;
  background: rgba(33, 76, 133, 0.06);
  color: var(--accent-deep);
  font-weight: 700;
}

.status-dot {
  width: 10px;
  height: 10px;
  border-radius: 999px;
  background: var(--success);
  box-shadow: 0 0 0 5px rgba(141, 210, 184, 0.12);
}

.trust-grid,
.steps-grid,
.faq-list {
  display: grid;
  gap: 18px;
}

.trust-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
  padding: 12px 0 56px;
}

.feature-card {
  padding: 24px;
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, 0.06);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition), border-color var(--transition);
}

.feature-card:hover,
.step-card:hover,
.faq-item:hover {
  transform: translateY(-4px);
  border-color: rgba(212, 171, 86, 0.24);
}

.feature-index,
.step-no {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: 14px;
  background: rgba(212, 171, 86, 0.12);
  color: var(--accent-strong);
  font-weight: 800;
}

.feature-card h3,
.step-card h3,
.faq-item h3 {
  margin: 18px 0 10px;
  font-size: 1.1rem;
  color: var(--text-strong);
}

.feature-card p,
.step-card p,
.faq-item p {
  margin: 0;
  line-height: 1.75;
  color: var(--text-muted);
}

.install-section,
.faq-section {
  padding: 42px 0 0;
}

.section-heading {
  max-width: 700px;
  margin-bottom: 26px;
}

.section-heading h2 {
  font-size: clamp(2rem, 4vw, 3rem);
  color: var(--text-strong);
}

.section-heading p {
  margin-top: 12px;
  color: var(--text-muted);
}

.steps-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.step-card,
.faq-item {
  padding: 26px;
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, 0.05);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition), border-color var(--transition);
}

.faq-list {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  padding-bottom: 32px;
}

@keyframes fade-up {
  from {
    opacity: 0;
    transform: translateY(18px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 1080px) {
  .hero,
  .trust-grid,
  .steps-grid,
  .faq-list {
    grid-template-columns: 1fr;
  }

  .hero-copy h1 {
    max-width: none;
  }
}

@media (max-width: 760px) {
  .page-shell {
    width: min(calc(100% - 24px), var(--content-width));
    padding-top: 16px;
  }

  .topbar {
    align-items: flex-start;
    flex-direction: column;
    padding-bottom: 18px;
  }

  .hero-copy,
  .download-card,
  .feature-card,
  .step-card,
  .faq-item {
    padding: 22px;
    border-radius: 22px;
  }

  .hero-copy h1 {
    font-size: clamp(2.2rem, 12vw, 3.4rem);
  }

  .hero-actions {
    flex-direction: column;
  }

  .button {
    width: 100%;
  }
}