:root { --navy: #1F3560; --light: #90CAED; --ink: #333; --muted: #57595A; --bg: #F5F5F5; }
* { box-sizing: border-box; }
body {
  margin: 0; min-height: 100vh; display: grid; place-items: center; padding: 24px 16px;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif; color: var(--ink); background: var(--bg);
  line-height: 1.5;
}
.card {
  width: min(440px, 100%); background: #fff; border-radius: 20px; padding: 32px 28px;
  box-shadow: 0 1px 2px rgba(19, 34, 41, .06), 0 8px 24px rgba(19, 34, 41, .06);
  display: flex; flex-direction: column; gap: 1rem;
}
.logo { width: 220px; max-width: 100%; height: auto; align-self: center; }
h1 { color: var(--navy); font-size: 1.35rem; margin: .5rem 0 0; }
p { margin: 0; }
.hint { color: var(--muted); font-size: .9rem; }
.en { color: var(--muted); font-size: .85rem; border-top: 1px solid #E5E5E5; padding-top: .75rem; }
.code-box { display: flex; flex-direction: column; gap: .35rem; background: #EEF6FC; border-radius: 12px; padding: 14px 16px; }
.code-box[hidden] { display: none; }
.code-label { font-size: .8rem; text-transform: uppercase; letter-spacing: .05em; color: var(--muted); }
.code-box code {
  font-size: clamp(1.1rem, 6.5vw, 1.6rem); letter-spacing: .06em; white-space: nowrap;
  color: var(--navy); font-family: ui-monospace, Consolas, monospace;
}
@media (max-width: 380px) {
  body { padding: 12px 10px; }
  .card { padding: 22px 16px; border-radius: 16px; }
}