:root { color-scheme: light dark; }
* { box-sizing: border-box; }
body {
  margin: 0; padding: 2rem 1rem;
  font: 16px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: #f6f7f9; color: #1a1c1f;
}
main { max-width: 34rem; margin: 0 auto; background: #fff; padding: 1.75rem 2rem 2rem;
  border-radius: 12px; box-shadow: 0 1px 3px rgba(0,0,0,.08), 0 8px 24px rgba(0,0,0,.05); }
h1 { font-size: 1.05rem; font-weight: 600; color: #6b7280; margin: 0 0 1.5rem; letter-spacing: .01em; }
h2 { font-size: 1.4rem; margin: 0 0 1rem; }
h3 { font-size: 1rem; margin: 1.75rem 0 .75rem; padding-bottom: .35rem; border-bottom: 1px solid #e5e7eb; }
label { display: block; margin: .85rem 0; font-size: .9rem; color: #374151; }
input, select { display: block; width: 100%; margin-top: .3rem; padding: .55rem .7rem;
  font: inherit; border: 1px solid #d1d5db; border-radius: 7px; background: #fff; color: inherit; }
input:focus, select:focus { outline: 2px solid #2563eb; outline-offset: 1px; border-color: #2563eb; }
button { margin: 1.25rem .5rem 0 0; padding: .6rem 1.25rem; font: inherit; font-weight: 500;
  color: #fff; background: #2563eb; border: 0; border-radius: 7px; cursor: pointer; }
button:hover { background: #1d4ed8; }
button.secondary { background: #e5e7eb; color: #374151; }
button.secondary:hover { background: #d1d5db; }
p.note  { font-size: .875rem; color: #6b7280; }
p.error { padding: .7rem .9rem; background: #fef2f2; border-left: 3px solid #dc2626; color: #991b1b; border-radius: 4px; }
p.warn  { padding: .7rem .9rem; background: #fffbeb; border-left: 3px solid #d97706; color: #92400e; border-radius: 4px; }
p.ok    { padding: .7rem .9rem; background: #f0fdf4; border-left: 3px solid #16a34a; color: #166534; border-radius: 4px; }
pre, code { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: .875rem; }
pre { padding: .7rem .9rem; background: #f3f4f6; border-radius: 7px; overflow-x: auto; }
a { color: #2563eb; }
@media (prefers-color-scheme: dark) {
  body { background: #111315; color: #e5e7eb; }
  main { background: #1a1d21; box-shadow: none; }
  h1 { color: #9ca3af; }
  h3 { border-color: #2d3238; }
  label { color: #d1d5db; }
  input, select { background: #111315; border-color: #3a4048; color: #e5e7eb; }
  button.secondary { background: #2d3238; color: #e5e7eb; }
  pre { background: #111315; }
  p.error { background: #2a1618; } p.warn { background: #2a2216; } p.ok { background: #14231a; }
}