:root {
  --paper: #f8f9fb;
  --ink: #1b2030;
  --muted: #535b6e;
  --accent: #24479a;
  --hairline: #d6dbe4;
  color-scheme: light;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 18px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
main { max-width: 34rem; margin: 0 auto; padding: 2.5rem 20px; }
.crumb, .back { font-size: 0.85rem; color: var(--muted); }
h1 { font-size: 1.8rem; line-height: 1.2; font-weight: 600; margin: 1.5rem 0 0.8rem; }
a { color: var(--accent); }
code { font-size: 0.85em; background: #eef1f6; border: 1px solid var(--hairline); border-radius: 2px; padding: 0 0.25em; }
button {
  font: inherit;
  color: #fff;
  background: var(--accent);
  border: 0;
  border-radius: 4px;
  padding: 0.45rem 1rem;
  cursor: pointer;
}
button:hover { filter: brightness(1.1); }
button:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
#message { font-size: 1.2rem; min-height: 1.6em; }