:root {
  color-scheme: light dark;
  --bg: #f5f6f8;
  --fg: #1a1a1a;
  --card: #ffffff;
  --border: #e2e4e9;
  --accent: #4f46e5;
  --muted: #6b7280;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d0f14;
    --fg: #e6e8ec;
    --card: #161922;
    --border: #2a2f3a;
    --accent: #818cf8;
    --muted: #9aa0aa;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  background: var(--bg);
  color: var(--fg);
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
}

.card {
  width: min(360px, 90vw);
  padding: 2rem;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: 0 8px 30px rgb(0 0 0 / 8%);
}

h1 {
  margin: 0 0 0.25rem;
  font-size: 1.5rem;
}

.lead {
  margin: 0 0 1.5rem;
  color: var(--muted);
  font-size: 0.9rem;
}

form {
  display: grid;
  gap: 1rem;
}

label {
  display: grid;
  gap: 0.35rem;
  font-size: 0.85rem;
  color: var(--muted);
}

input {
  padding: 0.6rem 0.75rem;
  font-size: 1rem;
  color: var(--fg);
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 8px;
}

input:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

button {
  margin-top: 0.5rem;
  padding: 0.65rem;
  font-size: 1rem;
  font-weight: 600;
  color: #fff;
  background: var(--accent);
  border: none;
  border-radius: 8px;
  cursor: pointer;
}

button:hover {
  filter: brightness(1.05);
}

#message {
  margin: 0;
  min-height: 1.2em;
  font-size: 0.85rem;
}

#message.ok {
  color: #16a34a;
}

#message.err {
  color: #dc2626;
}