:root {
  --bg: #eaf4fc;
  --card: #ffffff;
  --primary: #2a7fc4;
  --primary-dark: #1d5f96;
  --text: #1f2d3a;
  --muted: #546474;
  --border: #b9d6ee;
  --error: #b3261e;
  --warn: #8a5a00;
  --ok: #1e6b3a;
  font-family: "Hiragino Sans", "Noto Sans JP", "Yu Gothic UI", "Meiryo", system-ui, sans-serif;
}
* { box-sizing: border-box; }
body { margin: 0; background: linear-gradient(180deg, #d9ecfa 0%, var(--bg) 40%); color: var(--text); min-height: 100vh; line-height: 1.7; }
.topbar { padding: 1.5rem 1rem 0.5rem; text-align: center; }
.topbar h1 { margin: 0; font-size: 1.5rem; color: var(--primary-dark); letter-spacing: 0.05em; }
.badge { display: inline-block; margin: 0.4rem 0 0; padding: 0.1rem 0.7rem; border-radius: 999px; background: #cfe6f8; color: var(--primary-dark); font-size: 0.8rem; }
.card { max-width: 26rem; margin: 1rem auto; padding: 1.5rem 1.75rem; background: var(--card); border: 1px solid var(--border); border-radius: 12px; box-shadow: 0 4px 18px rgba(42, 127, 196, 0.12); }
h2 { font-size: 1.15rem; margin: 0 0 1rem; color: var(--primary-dark); outline: none; }
label { display: block; margin: 0.9rem 0 0.25rem; font-weight: 600; font-size: 0.92rem; }
input { width: 100%; padding: 0.65rem 0.75rem; border: 1px solid var(--border); border-radius: 8px; font-size: 1rem; background: #fbfdff; }
input:focus-visible, button:focus-visible, a:focus-visible { outline: 3px solid #7fb9e6; outline-offset: 2px; }
button { margin-top: 1.1rem; padding: 0.65rem 1.1rem; border-radius: 8px; border: 1px solid var(--primary); background: #fff; color: var(--primary-dark); font-size: 1rem; cursor: pointer; }
button.primary { width: 100%; background: var(--primary); color: #fff; }
button.primary:hover { background: var(--primary-dark); }
button:disabled { opacity: 0.55; cursor: not-allowed; }
.row { display: flex; gap: 0.75rem; flex-wrap: wrap; }
.row button { flex: 1; }
.links { margin-top: 1rem; text-align: center; font-size: 0.92rem; }
a { color: var(--primary-dark); }
#status { min-height: 1.5rem; margin: 0 0 0.75rem; font-size: 0.92rem; }
#status[data-kind="error"] { color: var(--error); }
#status[data-kind="warn"] { color: var(--warn); }
#status[data-kind="ok"] { color: var(--ok); }
.notice { padding: 0.75rem; margin-bottom: 1rem; background: #fff7e0; border: 1px solid #f0d58a; border-radius: 8px; font-size: 0.9rem; }
.warn-text { color: var(--warn); font-size: 0.88rem; }
.secret { display: block; padding: 0.6rem; margin: 0.5rem 0; background: #f2f8fd; border: 1px dashed var(--border); border-radius: 6px; font-size: 1.05rem; letter-spacing: 0.12em; word-break: break-all; user-select: all; }
.facts { display: grid; grid-template-columns: max-content 1fr; gap: 0.3rem 1rem; margin: 0 0 0.5rem; }
.facts dt { color: var(--muted); }
.facts dd { margin: 0; font-weight: 600; }
.foot { text-align: center; color: var(--muted); font-size: 0.8rem; padding: 1rem; }
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
@media (prefers-reduced-motion: no-preference) { button { transition: background 0.15s; } }
.qr-wrap { margin: 0.5rem 0 0.75rem; display: flex; flex-direction: column; align-items: center; gap: 0.6rem; }
.qr-wrap canvas { width: min(264px, 70vw); height: auto; image-rendering: pixelated; border: 1px solid var(--border); border-radius: 6px; background: #fff; }
.qr-wrap figcaption { font-size: 0.88rem; color: var(--muted); }
.hint { margin: 0.5rem 0 0; font-size: 0.88rem; color: var(--muted); }
@media (max-width: 480px) {
  .card { margin: 0.5rem; padding: 1.1rem 1rem; }
  .qr-wrap canvas { width: min(220px, 60vw); }
}