:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --fg: #16161a;
  --muted: #6b6b76;
  --panel: #f2f2f6;
  --accent: #0a7aff;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000000;
    --fg: #f5f5f7;
    --muted: #9a9aa4;
    --panel: #1c1c1f;
    --accent: #3d9bff;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 17px/1.5 -apple-system, BlinkMacSystemFont, "PingFang SC", "PingFang TC", "Microsoft YaHei", sans-serif;
  padding: max(40px, env(safe-area-inset-top)) max(20px, env(safe-area-inset-right)) 40px max(20px, env(safe-area-inset-left));
}
main { max-width: 26rem; margin: 0 auto; display: grid; gap: 16px; }
h1 { font-size: 26px; line-height: 1.25; margin: 0; }
p { margin: 0; }
#lead { color: var(--muted); }
#code-box { background: var(--panel); border-radius: 14px; padding: 16px; display: grid; gap: 8px; }
#code-label { font-size: 13px; color: var(--muted); }
#code { font: 600 21px/1.3 ui-monospace, SFMono-Regular, Menlo, monospace; letter-spacing: 0.02em; overflow-wrap: anywhere; user-select: all; -webkit-user-select: all; }
button, .primary, .secondary {
  display: block;
  width: 100%;
  border: 0;
  border-radius: 12px;
  padding: 13px 16px;
  font: inherit;
  font-weight: 600;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
}
.primary { background: var(--accent); color: #ffffff; }
.secondary, button { background: var(--panel); color: var(--accent); }
#code-box button { background: var(--bg); }
.note { font-size: 14px; color: var(--muted); }
[hidden] { display: none !important; }