:root {
  color-scheme: light;
  --ink: #17211c;
  --muted: #5e6a64;
  --surface: #ffffff;
  --canvas: #f2f4f1;
  --brand: #1f6a4b;
  --brand-hover: #19563d;
  --border: #d6ddd8;
  --danger-bg: #fff1f0;
  --danger: #8a1c15;
  --notice-bg: #eef7f1;
  --radius: 18px;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--ink);
  background: var(--canvas);
}
.auth-shell { min-height: 100vh; display: grid; place-items: center; padding: 24px; }
.auth-card {
  width: min(100%, 470px);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: clamp(24px, 5vw, 44px);
  box-shadow: 0 18px 50px rgba(25, 45, 34, .08);
}
.brand { font-size: 1.25rem; font-weight: 800; color: var(--brand); letter-spacing: -.03em; margin-bottom: 32px; }
h1 { margin: 0 0 12px; font-size: clamp(1.8rem, 5vw, 2.5rem); line-height: 1.08; letter-spacing: -.04em; }
.lead { color: var(--muted); line-height: 1.55; margin: 0 0 28px; }
label { display: block; font-weight: 700; margin: 18px 0 8px; }
input {
  width: 100%; border: 1px solid var(--border); border-radius: 10px; padding: 13px 14px;
  font: inherit; color: inherit; background: #fff;
}
input:focus-visible, button:focus-visible, a:focus-visible { outline: 3px solid rgba(31, 106, 75, .3); outline-offset: 2px; }
button, .button {
  display: inline-flex; align-items: center; justify-content: center; width: 100%; margin-top: 24px;
  border: 0; border-radius: 10px; padding: 14px 18px; font: inherit; font-weight: 800;
  text-decoration: none; background: var(--brand); color: white; cursor: pointer;
}
button:hover, .button:hover { background: var(--brand-hover); }
.secondary { text-align: center; margin: 22px 0 0; }
a { color: var(--brand); }
.alert, .notice { border-radius: 10px; padding: 12px 14px; margin-bottom: 20px; line-height: 1.45; }
.alert { background: var(--danger-bg); color: var(--danger); }
.notice { background: var(--notice-bg); color: var(--ink); }
.qr { display: block; max-width: 100%; height: auto; margin: 0 auto 18px; }
.secret { margin: 0; background: var(--canvas); border-radius: 10px; padding: 14px; overflow-wrap: anywhere; }
.secret dt { font-size: .85rem; color: var(--muted); }
.secret dd { margin: 5px 0 0; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; }