:root {
  color-scheme: light;
  --ink: #0b0b0b;
  --muted: #656565;
  --rule: #d8d8d8;
  --paper: #ffffff;
  --soft: #f5f5f3;
  --radius: 28px;
  --content: 760px;
}

* { box-sizing: border-box; }

html { background: var(--paper); }

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "SF Pro Text", "PingFang SC", "Noto Sans CJK SC", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-decoration-thickness: 1px;
  text-underline-offset: 4px;
}

a:focus-visible {
  outline: 2px solid var(--ink);
  outline-offset: 5px;
  border-radius: 2px;
}

.shell {
  width: min(calc(100% - 40px), var(--content));
  margin: 0 auto;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 76px;
  border-bottom: 1px solid var(--rule);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  font-weight: 650;
  letter-spacing: .02em;
  text-decoration: none;
}

.mark {
  width: 32px;
  height: 32px;
  flex: 0 0 32px;
  border-radius: 7px;
  background: var(--paper) url("app-icon-192.png") center / cover no-repeat;
  box-shadow: inset 0 0 0 1px rgba(0, 0, 0, .08);
}

.nav {
  display: flex;
  gap: 20px;
  color: var(--muted);
  font-size: 14px;
}

main { padding: 78px 0 92px; }

.eyebrow {
  margin: 0 0 18px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 650;
  letter-spacing: .16em;
  text-transform: uppercase;
}

h1 {
  max-width: 660px;
  margin: 0;
  font-family: "SF Pro Display", "PingFang SC", system-ui, sans-serif;
  font-size: clamp(44px, 9vw, 78px);
  font-weight: 520;
  line-height: .98;
  letter-spacing: -.055em;
}

.lead {
  max-width: 620px;
  margin: 28px 0 0;
  color: var(--muted);
  font-size: clamp(18px, 2.5vw, 22px);
  line-height: 1.55;
}

.proof {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  margin: 54px 0 70px;
  border: 1px solid var(--ink);
  border-radius: var(--radius);
  overflow: hidden;
}

.proof div { padding: 22px 24px; }
.proof div + div { border-left: 1px solid var(--ink); }

.proof strong {
  display: block;
  margin-bottom: 2px;
  font-size: 17px;
  font-weight: 650;
}

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

.section {
  padding: 34px 0;
  border-top: 1px solid var(--rule);
}

.section h2 {
  margin: 0 0 14px;
  font-size: 20px;
  font-weight: 650;
  letter-spacing: -.02em;
}

.section p { margin: 0 0 13px; }
.section p:last-child { margin-bottom: 0; }

.section ul,
.section ol {
  margin: 12px 0 0;
  padding-left: 1.35em;
}

.section li + li { margin-top: 8px; }

.note {
  margin-top: 24px;
  padding: 18px 20px;
  border-radius: 18px;
  background: var(--soft);
  color: var(--muted);
  font-size: 14px;
}

.contact {
  display: inline-flex;
  align-items: center;
  min-height: 48px;
  margin-top: 8px;
  padding: 0 18px;
  border: 1px solid var(--ink);
  border-radius: 999px;
  font-weight: 620;
  text-decoration: none;
}

footer {
  padding: 26px 0 38px;
  border-top: 1px solid var(--rule);
  color: var(--muted);
  font-size: 13px;
}

@media (max-width: 620px) {
  .shell { width: min(calc(100% - 28px), var(--content)); }
  .topbar { min-height: 66px; }
  .nav { gap: 13px; font-size: 13px; }
  main { padding: 54px 0 70px; }
  .proof { grid-template-columns: 1fr; margin: 42px 0 54px; }
  .proof div + div { border-left: 0; border-top: 1px solid var(--ink); }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; }
}