:root {
  color-scheme: dark;
  --bg: #07080c;
  --surface: #161821;
  --line: #2a2d3a;
  --text: #f2f3f7;
  --muted: #a3a7b7;
  --accent: #7fd1c7;
  --error: #ff8a80;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  background: radial-gradient(120% 60% at 50% 0%, #142a33 0%, var(--bg) 60%);
  color: var(--text);
  font: 17px/1.45 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
main { max-width: 440px; margin: 0 auto; padding: 24px 16px 48px; }
.brand { color: var(--muted); letter-spacing: .08em; text-transform: uppercase; font-size: 13px; margin: 0 0 24px; }
h1 { font-size: 26px; margin: 0 0 8px; }
p { color: var(--muted); margin: 0 0 16px; }
.code strong { color: var(--text); letter-spacing: .2em; font-variant-numeric: tabular-nums; }
.chips { display: flex; gap: 8px; margin: 8px 0 16px; }
.chips label { flex: 1; }
.chips input { position: absolute; opacity: 0; pointer-events: none; }
.chips span {
  display: block; text-align: center; padding: 12px 8px; border-radius: 999px;
  background: var(--surface); border: 1px solid var(--line); color: var(--muted);
}
.chips input:checked + span { background: var(--accent); border-color: var(--accent); color: #062521; font-weight: 600; }
.chips input:focus-visible + span { outline: 2px solid var(--text); outline-offset: 2px; }
.field { display: block; margin: 0 0 14px; color: var(--muted); font-size: 15px; }
.field input {
  display: block; width: 100%; margin-top: 6px; padding: 13px 14px; font: inherit; color: var(--text);
  background: var(--surface); border: 1px solid var(--line); border-radius: 12px;
}
.field input:focus { outline: none; border-color: var(--accent); }
details { margin: 0 0 16px; }
summary { color: var(--muted); cursor: pointer; padding: 6px 0 12px; }
button, .button {
  display: block; width: 100%; padding: 15px; border: 0; border-radius: 14px; text-align: center;
  background: var(--accent); color: #062521; font: 600 17px/1.2 inherit; text-decoration: none; cursor: pointer;
}
button:disabled { opacity: .5; }
.status { margin-top: 14px; min-height: 1.4em; }
.status.error { color: var(--error); }
.status.done { color: var(--accent); }