:root {
  --bg: #f6f7f9; --card: #ffffff; --ink: #1d2433; --muted: #5b6475; --line: #d9dde5;
  --accent: #00A2FF; --accent-ink: #ffffff; --err: #b3261e;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #12151b; --card: #1c2029; --ink: #e8ebf1; --muted: #a2a9b7; --line: #343a46; --err: #ff8a80; }
}
* { box-sizing: border-box; }
body {
  margin: 0; min-height: 100vh; display: grid; place-items: center; padding: 16px;
  background: var(--bg); color: var(--ink);
  font: 16px/1.5 Figtree, system-ui, -apple-system, "Segoe UI", sans-serif;
}
main { width: 100%; max-width: 360px; background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 28px 24px; }
h1 { margin: 0 0 20px; font-size: 1.4rem; }
label { display: block; margin-bottom: 14px; font-size: .9rem; color: var(--muted); }
input {
  display: block; width: 100%; margin-top: 4px; padding: 10px 12px; font: inherit; color: var(--ink);
  background: transparent; border: 1px solid var(--line); border-radius: 8px;
}
input:focus { outline: 2px solid var(--accent); outline-offset: 1px; border-color: transparent; }
button {
  width: 100%; margin-top: 6px; padding: 11px; font: inherit; font-weight: 600;
  color: var(--accent-ink); background: var(--accent); border: 0; border-radius: 8px; cursor: pointer;
}
button:disabled { opacity: .6; cursor: wait; }
#msg { min-height: 1.5em; margin: 12px 0 0; color: var(--err); font-size: .9rem; }