:root {
  --bg: #0f1419;
  --fg: #e7ecf1;
  --muted: #9aa7b5;
  --line: #2a3540;
  --accent: #3d8bfd;
  --danger: #e35d6a;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: "Segoe UI", system-ui, sans-serif;
  background: radial-gradient(1200px 600px at 20% -10%, #1a2838, var(--bg));
  color: var(--fg);
  min-height: 100vh;
}
.wrap {
  max-width: 28rem;
  margin: 0 auto;
  padding: 3rem 1.25rem;
}
h1 { font-size: 1.5rem; font-weight: 600; margin: 0 0 0.35rem; }
h2 { font-size: 1rem; margin: 0 0 0.75rem; font-weight: 600; }
.lead { color: var(--muted); margin: 0 0 2rem; line-height: 1.45; }
section {
  border-top: 1px solid var(--line);
  padding: 1.25rem 0;
}
label { display: block; font-size: 0.85rem; color: var(--muted); margin: 0.5rem 0 0.25rem; }
input {
  width: 100%;
  padding: 0.65rem 0.75rem;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #0a0e12;
  color: var(--fg);
}
button {
  margin-top: 0.85rem;
  width: 100%;
  padding: 0.7rem 1rem;
  border: 0;
  border-radius: 6px;
  background: var(--accent);
  color: #fff;
  font-weight: 600;
  cursor: pointer;
}
button:hover { filter: brightness(1.08); }
.msg { min-height: 1.25rem; color: var(--danger); font-size: 0.9rem; }
.once {
  margin-top: 0.75rem;
  padding: 0.75rem;
  border: 1px dashed var(--line);
  border-radius: 6px;
  font-family: ui-monospace, monospace;
  font-size: 0.8rem;
  word-break: break-all;
  color: var(--fg);
}
.hidden { display: none; }
.foot { margin-top: 2rem; font-size: 0.85rem; }
.foot a { color: var(--muted); }