:root {
  --bg: #f4f5f7;
  --card: #ffffff;
  --text: #111827;
  --muted: #6b7280;
  --border: #e5e7eb;
  --accent: #2563eb;
  --ok: #15803d;
  --ng: #b91c1c;
  --warn-bg: #fef3c7;
  --err-bg: #fee2e2;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0f14;
    --card: #161b22;
    --text: #e6edf3;
    --muted: #8b949e;
    --border: #30363d;
    --accent: #4c8dff;
    --ok: #3fb950;
    --ng: #f85149;
    --warn-bg: #3a2f0b;
    --err-bg: #3d1214;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Hiragino Sans", sans-serif;
  -webkit-text-size-adjust: 100%;
}
main {
  max-width: 520px;
  margin: 0 auto;
  padding: calc(env(safe-area-inset-top) + 16px) 16px calc(env(safe-area-inset-bottom) + 24px);
}
h1 { font-size: 1.4rem; margin: 0; }
h2 { font-size: 1.1rem; margin: 24px 0 8px; }
h3 { font-size: 1rem; margin: 0 0 4px; }
.muted { color: var(--muted); font-size: .9rem; margin: 4px 0; }
code { font-size: .85em; }
.message { padding: 12px; border-radius: 10px; background: var(--warn-bg); margin: 16px 0; }
.message.error { background: var(--err-bg); }
.step, .req {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px;
  margin: 12px 0;
}
input {
  display: block;
  width: 100%;
  font-size: 1.1rem;
  padding: 10px 12px;
  margin: 8px 0;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--bg);
  color: var(--text);
}
button {
  display: block;
  width: 100%;
  font-size: 1.05rem;
  font-weight: 600;
  padding: 12px;
  margin: 8px 0 0;
  border: 0;
  border-radius: 10px;
  background: var(--accent);
  color: #fff;
}
button:disabled { opacity: .5; }
button.approve { background: var(--ok); }
button.deny { background: transparent; color: var(--ng); border: 1px solid var(--ng); }
button.secondary { background: transparent; color: var(--accent); border: 1px solid var(--border); font-weight: 500; }
.req .pc { font-size: 1.15rem; font-weight: 600; }
.req .number { font-size: 2.6rem; font-weight: 700; letter-spacing: .1em; text-align: center; margin: 8px 0; }
.req .status { text-align: center; font-weight: 600; }
.req .status.approved { color: var(--ok); }
.req .status.denied, .req .status.expired { color: var(--ng); }
footer { margin-top: 32px; }