:root {
  color-scheme: light dark;
  --bg: #fbfaf7;
  --card: #fff;
  --ink: #1d1d1f;
  --muted: #6b6a66;
  --line: #e3e1db;
  --accent: #299bbd;
  --warn: #b5482a;
  --button: #1d1d1f;
  --on-button: #fff;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121212;
    --card: #1c1c1e;
    --ink: #f5f5f7;
    --muted: #aaa9af;
    --line: #333337;
    --accent: #5bc8f5;
    --warn: #f08a6c;
    --button: #f5f5f7;
    --on-button: #121212;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.55 system-ui, -apple-system, "Segoe UI", sans-serif;
}
main { max-width: 640px; margin: 0 auto; padding: 32px 16px 48px; }
h1 { font-size: 1.9rem; line-height: 1.2; margin: 0 0 8px; }
h2 { font-size: 1.2rem; margin: 0 0 8px; }
.lead { color: var(--muted); margin: 0 0 24px; }
section {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 20px;
  margin: 0 0 16px;
}
ol { padding-left: 1.2em; margin: 0; }
li + li { margin-top: 8px; }
a { color: var(--accent); }
.note { color: var(--muted); font-size: 0.95rem; }
label { display: block; font-weight: 600; margin: 14px 0 4px; }
label span { font-weight: 400; color: var(--muted); }
input {
  width: 100%;
  padding: 10px 12px;
  font: inherit;
  color: inherit;
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 10px;
}
button {
  margin-top: 18px;
  padding: 11px 18px;
  font: inherit;
  font-weight: 600;
  color: var(--on-button);
  background: var(--button);
  border: 0;
  border-radius: 999px;
  cursor: pointer;
}
.error, .warning { color: var(--warn); }
#qr {
  display: block;
  width: 100%;
  max-width: 320px;
  height: auto;
  margin: 8px auto 16px;
  background: #fff;
  border-radius: 8px;
  image-rendering: pixelated;
}
.device { margin: 0 0 24px; text-align: center; }
.device svg { display: block; width: 100%; max-width: 300px; height: auto; margin: 0 auto 10px; }
.device figcaption { color: var(--muted); font-size: 0.95rem; }
footer { color: var(--muted); font-size: 0.9rem; text-align: center; }