:root {
  --color-bg: #0c111b;
  --color-surface: #151d2b;
  --color-surface-2: #eef2f7;
  --color-text: #f7f9fc;
  --color-ink: #172033;
  --color-text-muted: #aab5c7;
  --color-accent: #22c55e;
  --color-primary: #2563eb;
  --color-border: rgba(255, 255, 255, 0.12);
  --radius: 8px;
  --container-max: 1120px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; }
html, body {
  margin: 0;
  padding: 0;
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.55;
}
a { color: inherit; text-decoration: none; }
.container { max-width: var(--container-max); margin: 0 auto; padding: 0 20px; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(12, 17, 27, 0.88);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(12px);
}
.header-inner { display: flex; align-items: center; height: 64px; gap: 24px; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 800; }
.brand-mark {
  display: inline-grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: var(--color-accent);
  color: #052e16;
  font-size: 11px;
  letter-spacing: 0;
}
.brand-name { font-size: 17px; }
.primary-nav { margin-left: auto; display: flex; gap: 18px; font-size: 14px; color: var(--color-text-muted); }
.primary-nav a:hover { color: var(--color-text); }
.lang-switcher { display: none; }

.hero {
  min-height: calc(100vh - 64px);
  display: flex;
  align-items: center;
  padding: 80px 0 110px;
  position: relative;
  overflow: hidden;
}
.app-hero {
  background:
    linear-gradient(90deg, rgba(12, 17, 27, 0.98) 0%, rgba(12, 17, 27, 0.88) 44%, rgba(12, 17, 27, 0.42) 100%),
    url("app-onboarding.png") right 9% center / min(430px, 42vw) auto no-repeat,
    #0c111b;
}
.hero::after {
  content: "";
  position: absolute;
  inset: auto 0 0;
  height: 110px;
  background: linear-gradient(180deg, transparent, var(--color-bg));
}
.hero-inner { position: relative; z-index: 1; max-width: 690px; }
.hero-badge {
  margin: 0 0 20px;
  color: #67e8f9;
  font-size: 14px;
  font-weight: 800;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}
.hero h1 {
  margin: 0 0 18px;
  font-size: clamp(46px, 7vw, 88px);
  line-height: 0.98;
  font-weight: 900;
  letter-spacing: 0;
}
.hero-subtitle {
  max-width: 620px;
  margin: 0 0 34px;
  color: #c5cfdd;
  font-size: clamp(18px, 2.2vw, 23px);
}
.hero-ctas, .store-badges, .footer-links { display: flex; gap: 14px; flex-wrap: wrap; }
.btn {
  display: inline-flex;
  align-items: center;
  min-height: 46px;
  padding: 0 20px;
  border-radius: var(--radius);
  font-weight: 750;
}
.btn-primary { background: var(--color-accent); color: #052e16; }
.btn-ghost { border: 1px solid var(--color-border); background: rgba(255,255,255,0.08); }

.features { padding: 76px 0; }
.features h2, .download h2 {
  margin: 0 0 34px;
  font-size: clamp(28px, 4vw, 42px);
  line-height: 1.15;
  letter-spacing: 0;
}
.feature-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(270px, 1fr)); gap: 16px; }
.feature-card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 22px;
  background: var(--color-surface);
}
.feature-icon { color: var(--color-accent); font-size: 13px; font-weight: 850; text-transform: uppercase; letter-spacing: 0.12em; }
.feature-card h3 { margin: 12px 0 6px; font-size: 19px; }
.feature-card p { margin: 0; color: var(--color-text-muted); font-size: 15px; }

.download { padding: 76px 0 92px; background: var(--color-surface-2); color: var(--color-ink); text-align: center; }
.download h2 { margin-bottom: 12px; }
.download-inner > p { max-width: 680px; margin: 0 auto 30px; color: #526070; font-size: 17px; }
.store-badges { justify-content: center; }
.store-badge {
  min-width: 176px;
  padding: 10px 18px;
  border-radius: var(--radius);
  background: #101827;
  color: #fff;
  text-align: left;
}
.store-small { display: block; font-size: 11px; color: #aab5c7; }
.store-large { display: block; font-size: 18px; font-weight: 850; }
.store-badge-placeholder { opacity: 0.75; cursor: default; }

.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 40px 0 30px;
  background: var(--color-surface);
  color: var(--color-text-muted);
  font-size: 14px;
}
.footer-inner { display: grid; gap: 20px; }
.footer-brand .brand-name { color: var(--color-text); }
.footer-tagline { margin: 8px 0 0; font-size: 13.5px; }
.footer-links a:hover { color: var(--color-text); }
.footer-copy { font-size: 12.5px; opacity: 0.8; }

.doc-page { background: var(--color-bg); }
.doc-main { padding: 60px 0 80px; }
.doc-article { max-width: 780px; }
.doc-article h1 { font-size: 36px; margin: 0 0 8px; }
.doc-article h2 { font-size: 20px; margin: 32px 0 10px; }
.doc-article p, .doc-article li { font-size: 15.5px; color: #d4dbec; }
.doc-article ul { padding-left: 20px; }
.doc-article li { margin-bottom: 6px; }
.doc-article a { color: var(--color-accent); text-decoration: underline; text-underline-offset: 3px; }
.doc-meta { color: var(--color-text-muted); font-size: 13.5px; }

@media (max-width: 760px) {
  .primary-nav { display: none; }
  .hero { min-height: 820px; align-items: flex-start; padding-top: 58px; }
  .app-hero {
    background:
      linear-gradient(180deg, rgba(12, 17, 27, 0.96) 0%, rgba(12, 17, 27, 0.86) 46%, rgba(12, 17, 27, 0.58) 100%),
      url("app-onboarding.png") center bottom 28px / min(330px, 74vw) auto no-repeat,
      #0c111b;
  }
}