:root {
  color-scheme: light;
  --bg: #f0f2f5;
  --card: #fff;
  --text: #1f2329;
  --muted: #646a73;
  --blue: #267ef0;
  --blue-hover: #1a6fd4;
  --border: rgba(6, 15, 26, 0.08);
  --ok: #2ea121;
  --warn: #c27500;
  --err: #d14343;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  padding: 24px;
}

.card {
  width: min(400px, 100%);
  background: var(--card);
  border-radius: 16px;
  padding: 28px 24px 24px;
  box-shadow: 0 10px 40px rgba(15, 23, 42, 0.08);
  border: 1px solid var(--border);
  text-align: center;
}

h1 {
  margin: 0 0 8px;
  font-size: 1.35rem;
  font-weight: 600;
}

.sub {
  margin: 0 0 20px;
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.5;
}

.qr-wrap {
  width: 260px;
  height: 260px;
  margin: 0 auto 16px;
  border: 1px solid var(--border);
  border-radius: 14px;
  display: grid;
  place-items: center;
  background: #fff;
  overflow: hidden;
}

.qr-wrap img {
  width: 240px;
  height: 240px;
  display: block;
}

.placeholder {
  color: var(--muted);
  font-size: 0.9rem;
  padding: 16px;
}

.status {
  min-height: 1.4em;
  margin: 0 0 12px;
  font-size: 0.95rem;
  color: var(--muted);
}

.status.ok { color: var(--ok); }
.status.warn { color: var(--warn); }
.status.err { color: var(--err); }

.actions { margin-top: 8px; }

.btn {
  appearance: none;
  border: 1px solid var(--border);
  background: #fff;
  color: var(--text);
  border-radius: 10px;
  padding: 10px 16px;
  font-size: 0.95rem;
  cursor: pointer;
}

.btn:hover { background: #f7f8fa; }

.btn.primary {
  background: var(--blue);
  border-color: var(--blue);
  color: #fff;
  width: 100%;
  margin-top: 12px;
}

.btn.primary:hover { background: var(--blue-hover); }

.hint {
  margin: 16px 0 0;
  font-size: 0.8rem;
  color: var(--muted);
}

.hint code, code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.85em;
  background: #f2f3f5;
  padding: 1px 6px;
  border-radius: 4px;
}

.otp-form {
  text-align: left;
  display: grid;
  gap: 8px;
}

.otp-form label {
  font-size: 0.9rem;
  color: var(--muted);
}

.otp-form input {
  width: 100%;
  font-size: 1.4rem;
  letter-spacing: 0.25em;
  text-align: center;
  padding: 12px;
  border-radius: 10px;
  border: 1px solid var(--border);
  outline: none;
}

.otp-form input:focus {
  border-color: var(--blue);
  box-shadow: 0 0 0 3px rgba(38, 126, 240, 0.15);
}

a {
  color: var(--blue);
  text-decoration: none;
  font-size: 0.9rem;
}

a:hover { text-decoration: underline; }