:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #5a5a5a;
  --border: #8a8a8a;
  --accent: #1d4ed8;
  --accent-fg: #ffffff;
  --focus: #1d4ed8;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121212;
    --fg: #f0f0f0;
    --muted: #b5b5b5;
    --border: #8a8a8a;
    --accent: #7aa2ff;
    --accent-fg: #0b0b0b;
    --focus: #9db9ff;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 1rem/1.5 system-ui, -apple-system, "Segoe UI", sans-serif;
}
main {
  max-width: 24rem;
  margin: 0 auto;
  padding: 3rem 16px;
}
h1 { font-size: 1.5rem; line-height: 1.25; margin: 0 0 1.5rem; }
form { display: flex; flex-direction: column; gap: 0.75rem; }
form[hidden] { display: none; }
label { font-weight: 600; }
input {
  font: inherit;
  color: inherit;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.6rem 0.75rem;
  width: 100%;
}
button {
  font: inherit;
  font-weight: 600;
  border-radius: 6px;
  border: 1px solid var(--accent);
  background: var(--accent);
  color: var(--accent-fg);
  padding: 0.65rem 1rem;
  min-height: 44px;
  cursor: pointer;
}
button.secondary { background: transparent; color: var(--fg); border-color: var(--border); width: 100%; }
button.link { background: none; border: 0; color: var(--accent); text-decoration: underline; min-height: 0; padding: 0.25rem 0; font-weight: 400; align-self: flex-start; }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 2px; }
#status { min-height: 1.5rem; margin: 1rem 0; color: var(--muted); }
.or { text-align: center; color: var(--muted); margin: 0.5rem 0 1rem; }
.providers { display: flex; flex-direction: column; gap: 0.75rem; }
.providers[hidden], .or[hidden] { display: none; }
.choices { display: flex; gap: 0.75rem; }
.choices[hidden] { display: none; }
.choices button { flex: 1; }
button:disabled { opacity: 0.6; cursor: not-allowed; }