:root {
  --bg: #f6f2e8;
  --card: #fffdf7;
  --ink: #26433a;
  --muted: #6d7f77;
  --green: #3f7d5c;
  --line: #e2dccd;
  --warn: #a34b3d;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: radial-gradient(circle at 20% 0%, #eef6e8, transparent 40%), var(--bg);
  color: var(--ink);
  font: 16px/1.55 system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
}
.shell { max-width: 860px; margin: 0 auto; padding: 28px 18px 60px; }
header { margin-bottom: 20px; }
.brand { font-size: 28px; font-weight: 800; letter-spacing: .02em; }
.sub { color: var(--muted); margin-top: 4px; }
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 18px;
  margin: 14px 0;
  box-shadow: 0 10px 30px rgba(70, 85, 60, .06);
}
h1, h2 { margin: 0 0 8px; font-size: 20px; }
h1 { font-size: 24px; }
.row { display: flex; gap: 12px; flex-wrap: wrap; }
.row.between { justify-content: space-between; align-items: center; }
.stat { flex: 1 1 140px; text-align: center; }
.stat span { display: block; font-size: 26px; font-weight: 800; }
.stat small { color: var(--muted); }
label { display: block; margin: 12px 0; color: var(--muted); }
input {
  display: block; width: 100%; margin-top: 6px; padding: 12px 14px;
  border: 1px solid var(--line); border-radius: 12px; font-size: 16px;
  background: #fff; color: var(--ink);
}
button {
  border: 0; border-radius: 12px; padding: 12px 18px; font-size: 16px;
  background: var(--green); color: #fff; cursor: pointer; font-weight: 700;
}
button.ghost { background: transparent; color: var(--green); border: 1px solid var(--green); }
button:active { transform: translateY(1px); }
.muted { color: var(--muted); }
.hidden { display: none; }
.error { color: var(--warn); margin-top: 10px; }
.result {
  margin-top: 12px; padding: 14px; border-radius: 12px;
  background: #eef6e8; border: 1px dashed var(--green);
  font-size: 18px;
}
.code { font-size: 34px; font-weight: 900; letter-spacing: .18em; color: var(--green); }
.attempts { display: grid; gap: 8px; }
.attempt {
  display: grid; grid-template-columns: 1fr auto; gap: 4px 12px;
  padding: 10px 12px; border: 1px solid var(--line); border-radius: 12px;
  background: #fff;
}
.attempt .q { font-weight: 600; }
.attempt .meta { color: var(--muted); font-size: 13px; }
.badge { align-self: center; padding: 2px 10px; border-radius: 999px; font-size: 13px; font-weight: 700; }
.badge.ok { background: #dff0e2; color: #286244; }
.badge.no { background: #f7e3df; color: #8c3d31; }
footer { margin-top: 26px; font-size: 13px; text-align: center; }
@media (max-width: 560px) {
  .shell { padding: 18px 12px 44px; }
  .stat span { font-size: 22px; }
  .attempt { grid-template-columns: 1fr; }
}