:root {
  --bg: #0B1020;
  --surface: #141A2E;
  --surface-2: #10162A;
  --line: #242C44;
  --line-strong: #2F3A57;
  --text: #E8ECF8;
  --muted: #9AA4C0;
  --brand: #7C9CFF;
  --brand-dim: #5C7BE0;
  --good: #5BD08A;
  --radius: 14px;
  color-scheme: dark;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
h1, h2, h3 { line-height: 1.2; margin: 0; font-weight: 600; letter-spacing: -0.01em; }
p { margin: 0; }

.wrap { width: 100%; max-width: 1120px; margin: 0 auto; padding: 0 24px; }

/* nav */
.nav {
  position: sticky; top: 0; z-index: 20;
  background: rgba(11, 16, 32, 0.92);
  backdrop-filter: none;
  border-bottom: 1px solid var(--line);
}
.nav-inner { display: flex; align-items: center; gap: 28px; height: 66px; }
.brand { display: flex; align-items: center; gap: 9px; font-weight: 600; font-size: 17px; }
.links { display: flex; gap: 24px; flex: 1; }
.links a { color: var(--muted); font-size: 14px; }
.links a:hover { color: var(--text); }
.nav-actions { display: flex; align-items: center; gap: 12px; }

.lang {
  background: transparent; color: var(--muted);
  border: 1px solid var(--line-strong); border-radius: 999px;
  padding: 6px 14px; font-size: 13px; cursor: pointer;
  font-family: inherit;
}
.lang:hover { color: var(--text); border-color: var(--brand-dim); }

/* buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  height: 48px; padding: 0 22px; border-radius: 10px;
  font-size: 15px; font-weight: 500; border: 1px solid transparent;
  cursor: pointer; transition: background .15s, border-color .15s, color .15s;
}
.btn-sm { height: 38px; padding: 0 16px; font-size: 13px; border-radius: 9px;
  background: var(--brand); color: #0B1020; }
.btn-sm:hover { background: #93AEFF; }
.btn-primary { background: var(--brand); color: #0B1020; }
.btn-primary:hover { background: #93AEFF; }
.btn-ghost { border-color: var(--line-strong); color: var(--text); }
.btn-ghost:hover { border-color: var(--brand-dim); }

/* hero */
.hero { padding: 84px 0 72px; border-bottom: 1px solid var(--line); }
.hero-grid { display: grid; grid-template-columns: 1.15fr .85fr; gap: 56px; align-items: center; }
.chip {
  display: inline-block; padding: 5px 12px; border-radius: 999px;
  border: 1px solid var(--line-strong); color: var(--muted);
  font-size: 12px; letter-spacing: .04em; text-transform: uppercase;
}
.hero h1 { font-size: clamp(38px, 5.2vw, 58px); margin: 20px 0 18px; letter-spacing: -0.03em; }
.lede { color: var(--muted); font-size: 17px; max-width: 34em; }
.cta { display: flex; gap: 12px; margin-top: 30px; flex-wrap: wrap; }
.meta { display: flex; gap: 22px; list-style: none; padding: 0; margin: 26px 0 0; color: var(--muted); font-size: 13px; }
.meta strong { color: var(--text); font-weight: 500; }

/* phone mock */
.hero-art { display: flex; justify-content: center; }
.phone {
  width: 296px; border: 1px solid var(--line-strong); border-radius: 26px;
  background: var(--surface); padding: 16px; font-size: 13px;
}
.phone-bar { display: flex; justify-content: space-between; align-items: center;
  font-weight: 600; font-size: 15px; padding: 2px 4px 14px; }
.dot-live { width: 8px; height: 8px; border-radius: 50%; background: var(--good); }
.phone-status { color: var(--good); font-size: 12px; padding: 0 4px 12px; }
.phone-row {
  display: flex; align-items: center; gap: 10px;
  border: 1px solid var(--line); border-radius: 12px;
  padding: 11px 12px; margin-bottom: 8px; background: var(--surface-2);
}
.phone-row.selected { border-color: var(--brand-dim); }
.flag { width: 22px; height: 22px; border-radius: 6px; background: var(--brand); opacity: .85; }
.flag.dim { background: var(--line-strong); }
.row-text { display: flex; flex-direction: column; line-height: 1.35; flex: 1; }
.row-text strong { font-weight: 500; font-size: 13px; }
.row-text small { color: var(--muted); font-size: 11px; }
.tick { color: var(--brand); }
.phone-account {
  display: flex; justify-content: space-between; gap: 8px;
  color: var(--muted); font-size: 11px; padding: 10px 4px 12px;
  border-top: 1px solid var(--line); margin-top: 10px;
}
.phone-cta {
  background: var(--brand); color: #0B1020; text-align: center; font-weight: 600;
  border-radius: 10px; padding: 12px; font-size: 13px;
}

/* strip */
.strip { border-bottom: 1px solid var(--line); background: var(--surface-2); }
.strip-inner { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; padding: 26px 24px; }
.strip-inner div { display: flex; flex-direction: column; gap: 2px; }
.strip-inner strong { font-size: 14px; font-weight: 500; }
.strip-inner span { color: var(--muted); font-size: 12px; }

/* sections */
.section { padding: 84px 0; }
.section.alt { background: var(--surface-2); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.section h2 { font-size: clamp(26px, 3.2vw, 34px); letter-spacing: -0.02em; }
.section-lede { color: var(--muted); margin-top: 14px; max-width: 46em; }
.narrow { max-width: 780px; }

.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin-top: 40px; }
.card { border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; background: var(--surface); }
.card h3 { font-size: 16px; margin-bottom: 8px; }
.card p { color: var(--muted); font-size: 14px; }
.icon {
  width: 30px; height: 30px; border-radius: 8px; margin-bottom: 16px;
  display: flex; align-items: center; justify-content: center;
  background: rgba(124, 156, 255, 0.14); color: var(--brand);
  font-size: 13px; font-weight: 600;
}

/* steps */
.steps { list-style: none; counter-reset: step; padding: 0; margin: 40px 0 0;
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.steps li { counter-increment: step; border-top: 2px solid var(--brand-dim); padding-top: 18px; }
.steps li::before { content: "0" counter(step); color: var(--brand); font-size: 12px; letter-spacing: .08em; }
.steps h3 { font-size: 17px; margin: 8px 0; }
.steps p { color: var(--muted); font-size: 14px; }

/* download */
.download-grid { display: grid; grid-template-columns: .85fr 1.15fr; gap: 48px; align-items: start; }
.versions { width: 100%; border-collapse: collapse; font-size: 14px; }
.versions th { text-align: left; color: var(--muted); font-weight: 500; font-size: 12px;
  padding: 0 12px 10px; border-bottom: 1px solid var(--line); }
.versions td { padding: 14px 12px; border-bottom: 1px solid var(--line); vertical-align: top; color: var(--muted); }
.versions td:first-child { color: var(--text); white-space: nowrap; }
.versions a { color: var(--brand); }
.versions a:hover { text-decoration: underline; }
.tag { display: inline-block; font-size: 10px; padding: 2px 7px; border-radius: 999px;
  background: rgba(124, 156, 255, .16); color: var(--brand); margin-left: 4px; vertical-align: middle; }
.fine { color: var(--muted); font-size: 12px; margin-top: 18px; max-width: 34em; }

/* faq */
details { border-bottom: 1px solid var(--line); padding: 16px 0; }
summary { cursor: pointer; font-size: 15px; font-weight: 500; }
summary::marker { color: var(--brand-dim); }
details p { color: var(--muted); font-size: 14px; margin-top: 10px; max-width: 52em; }

/* footer */
.footer { border-top: 1px solid var(--line); padding: 44px 0 32px; }
.footer-inner { display: flex; justify-content: space-between; gap: 24px; flex-wrap: wrap; align-items: flex-start; }
.brand-text { font-weight: 600; font-size: 16px; }
.muted { color: var(--muted); font-size: 13px; margin-top: 6px; }
.footer-links { display: flex; gap: 20px; font-size: 13px; color: var(--muted); flex-wrap: wrap; }
.footer-links a:hover { color: var(--text); }
.legal { margin-top: 28px; color: var(--muted); font-size: 12px; }

/* responsive */
@media (max-width: 900px) {
  .hero-grid, .download-grid { grid-template-columns: 1fr; gap: 40px; }
  .hero-art { order: -1; }
  .cards, .steps { grid-template-columns: repeat(2, 1fr); }
  .strip-inner { grid-template-columns: repeat(2, 1fr); }
  .links { display: none; }
  .hero { padding: 56px 0; }
}
@media (max-width: 560px) {
  .cards, .steps { grid-template-columns: 1fr; }
  .nav-inner { gap: 12px; height: 60px; }
  .meta { flex-wrap: wrap; gap: 10px 18px; }
  .section { padding: 60px 0; }
}