:root {
  color-scheme: light dark;
  --ink: #071011;
  --paper: #f7fbfa;
  --muted: #63706d;
  --teal: #007d74;
  --amber: #d1841d;
  --line: rgba(7, 16, 17, .12);
  --glass: rgba(255,255,255,.68);
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: ui-sans-serif, -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", sans-serif;
  background:
    radial-gradient(circle at 20% 0%, rgba(0,125,116,.15), transparent 34rem),
    linear-gradient(140deg, #f7fbfa, #eef5f3 42%, #f8f0e5);
  color: var(--ink);
}
a { color: inherit; }
.skip-link { position: absolute; left: -999px; }
.skip-link:focus { left: 1rem; top: 1rem; background: white; padding: .75rem; z-index: 10; }
.nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem clamp(1rem, 4vw, 4rem);
  position: sticky;
  top: 0;
  backdrop-filter: blur(22px);
  background: rgba(247,251,250,.78);
  border-bottom: 1px solid var(--line);
  z-index: 2;
}
.brand { display: inline-flex; align-items: center; gap: .65rem; font-weight: 750; text-decoration: none; }
.nav div { display: flex; gap: 1rem; font-size: .95rem; }
.nav a { text-decoration: none; }
.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 480px);
  gap: clamp(2rem, 6vw, 6rem);
  align-items: center;
  min-height: calc(100vh - 88px);
  padding: clamp(2rem, 6vw, 6rem);
}
.hero-icon { width: 88px; height: 88px; filter: drop-shadow(0 20px 34px rgba(0,0,0,.18)); }
h1 { font-size: clamp(4rem, 15vw, 9rem); line-height: .86; margin: 1rem 0; letter-spacing: 0; }
.lead { font-size: clamp(1.8rem, 5vw, 4rem); line-height: 1; max-width: 13ch; margin: 0 0 1rem; font-weight: 730; }
p { color: var(--muted); font-size: 1.08rem; line-height: 1.65; }
.actions { display: flex; flex-wrap: wrap; gap: .8rem; margin-top: 1.5rem; }
.button {
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: .82rem 1.1rem;
  text-decoration: none;
  background: rgba(255,255,255,.58);
}
.primary { background: var(--teal); color: white; border-color: transparent; }
.device {
  border: 1px solid rgba(255,255,255,.7);
  border-radius: 38px;
  padding: 1.2rem;
  min-height: 620px;
  background: linear-gradient(180deg, rgba(255,255,255,.76), rgba(255,255,255,.36));
  box-shadow: 0 40px 90px rgba(0,0,0,.18);
}
.device-status { display: flex; justify-content: space-between; font-size: .82rem; color: var(--muted); }
.screen-card, .screen-grid > div, .receipt, .card {
  border: 1px solid var(--line);
  background: var(--glass);
  backdrop-filter: blur(18px);
  border-radius: 8px;
  padding: 1rem;
}
.screen-card { margin-top: 2rem; font-size: 1.6rem; font-weight: 740; }
.strong { color: #073f3b; }
.screen-grid { display: grid; grid-template-columns: 1fr 1fr; gap: .8rem; margin-top: .8rem; }
.receipt { margin-top: .8rem; color: #0b4c45; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 1rem; padding: 0 clamp(1rem, 6vw, 6rem) 4rem; }
.card h2 { margin: 0; font-size: 1.2rem; }
.band, .plain { padding: clamp(2rem, 6vw, 6rem); max-width: 980px; margin: 0 auto; }
.band { text-align: center; }
form { display: grid; gap: 1rem; max-width: 560px; }
input, textarea, button {
  width: 100%;
  font: inherit;
  border-radius: 8px;
  border: 1px solid var(--line);
  padding: .8rem;
}
textarea { min-height: 160px; }
button { background: var(--teal); color: white; border: 0; }
footer { display: flex; justify-content: space-between; gap: 1rem; padding: 2rem clamp(1rem, 4vw, 4rem); border-top: 1px solid var(--line); color: var(--muted); }
@media (max-width: 820px) {
  .hero { grid-template-columns: 1fr; min-height: auto; }
  .device { min-height: 420px; }
  .nav { align-items: flex-start; gap: .8rem; flex-direction: column; }
  footer { flex-direction: column; }
}
@media (prefers-reduced-motion: no-preference) {
  .button, .card, .screen-card { transition: transform .18s ease, box-shadow .18s ease; }
  .button:hover, .card:hover, .screen-card:hover { transform: translateY(-2px); }
}
@media (prefers-color-scheme: dark) {
  :root { --ink: #eff8f6; --paper: #071011; --muted: #a6b7b3; --line: rgba(255,255,255,.14); --glass: rgba(10,18,19,.62); }
  body { background: linear-gradient(140deg, #061010, #0d2422 52%, #251a0b); }
  .nav { background: rgba(6,16,16,.74); }
  .button { background: rgba(255,255,255,.08); }
  .primary { background: #0f8f84; }
  .device { background: linear-gradient(180deg, rgba(255,255,255,.12), rgba(255,255,255,.05)); }
  .strong, .receipt { color: #7de4d8; }
}