:root {
  --bg: #f6f7f9;
  --surface: #ffffff;
  --border: #d8dce3;
  --text: #1c2430;
  --muted: #5b6675;
  --accent: #1f6feb;
  --ok: #1a7f37;
  --warn: #9a6700;
  --danger: #b42318;
  --edited: #6f42c1;
  --radius: 10px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans TC",
    "PingFang TC", "Microsoft JhengHei", sans-serif;
}

.topbar {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: flex-end;
  justify-content: space-between;
  padding: 18px 24px 12px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

h1 { margin: 0; font-size: 20px; }
.sub { margin: 2px 0 0; color: var(--muted); font-size: 13px; }

.stats { display: flex; gap: 10px; flex-wrap: wrap; }
.stat {
  min-width: 84px;
  padding: 6px 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-align: center;
  background: var(--bg);
}
.stat span { display: block; font-size: 20px; font-weight: 700; }
.stat label { font-size: 12px; color: var(--muted); }
.stat.warn span { color: var(--warn); }
.stat.ok span { color: var(--ok); }
.stat.edited span { color: var(--edited); }
.stat.danger span { color: var(--danger); }

.toolbar {
  display: grid;
  gap: 10px;
  padding: 14px 24px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

.filters { display: flex; gap: 12px; flex-wrap: wrap; min-width: 0; }
.field { display: flex; flex-direction: column; gap: 4px; font-size: 12px; color: var(--muted); min-width: 0; flex: 0 1 200px; }
.field.grow { flex: 1 1 240px; }
.field select, .field input {
  min-width: 0;
  max-width: 100%;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  color: var(--text);
  font: inherit;
}
.field input { width: 100%; }

.chips { display: flex; gap: 8px; flex-wrap: wrap; }
.chip {
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
  font: inherit;
  font-size: 13px;
}
.chip[aria-pressed="true"] { background: var(--accent); border-color: var(--accent); color: #fff; }

.exports { display: flex; gap: 8px; flex-wrap: wrap; }

.btn {
  padding: 8px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
  font: inherit;
  font-size: 13px;
}
.btn:hover { border-color: var(--accent); }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.btn.primary { border-color: var(--accent); color: var(--accent); }
.btn.ok { border-color: var(--ok); color: var(--ok); }
.btn.danger { border-color: var(--danger); color: var(--danger); }
.btn.file { display: inline-flex; align-items: center; }

.help { margin: 14px 24px 0; padding: 0 4px; color: var(--muted); font-size: 13px; }
.help summary { cursor: pointer; }
.help ul { margin: 8px 0 0; padding-left: 20px; }

main { padding: 8px 24px 40px; max-width: 1180px; margin: 0 auto; overflow-x: clip; }
.listmeta { display: flex; justify-content: space-between; gap: 12px; padding: 10px 2px; color: var(--muted); font-size: 13px; }
.list { display: grid; grid-template-columns: minmax(0, 1fr); gap: 12px; min-width: 0; }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 16px;
  display: grid;
  gap: 10px;
  min-width: 0;
}
.card-head { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.badge {
  padding: 2px 8px;
  border-radius: 999px;
  font-size: 12px;
  border: 1px solid var(--border);
  background: var(--bg);
}
.badge.unit { border-color: #b9c6f5; color: #213a8f; background: #eef2ff; }
.badge.review.approved { border-color: #b7dfc3; color: var(--ok); background: #edf8f0; }
.badge.review.best_fit { border-color: #ecd9a6; color: var(--warn); background: #fff8e6; }
.badge.review.refined { border-color: #b9c6f5; color: #1f4fbf; background: #eef2ff; }
.badge.review.retained { border-color: #c9cdd4; color: var(--muted); background: #f2f4f7; }
.badge.review.unchanged { border-color: #f0b8b2; color: var(--danger); background: #fdf0ef; }
.badge.original { border-color: #c9cdd4; color: var(--muted); background: var(--bg); }
.stat.refined span { color: var(--accent); }
.badge.teacher.confirmed, .badge.teacher.set { border-color: #c9b8ea; color: var(--edited); background: #f5f0ff; }
.badge.teacher.unclassified { border-color: #f0b8b2; color: var(--danger); background: #fdf0ef; }
.badge.cross { border-color: #f0b8b2; color: var(--danger); background: #fdf0ef; }
.key { margin-left: auto; color: var(--muted); font-size: 12px; word-break: break-all; }

.question { white-space: pre-wrap; font-size: 16px; overflow-wrap: anywhere; }
.choices { display: grid; gap: 4px; }
.choice { padding: 4px 8px; border-radius: 6px; background: var(--bg); overflow-wrap: anywhere; }
.choice.correct { outline: 2px solid var(--ok); background: #edf8f0; }
.answers { color: var(--muted); overflow-wrap: anywhere; }
.answers strong { color: var(--text); }
.passage { white-space: pre-wrap; background: var(--bg); padding: 10px; border-radius: 8px; margin-top: 6px; overflow-wrap: anywhere; }

.ai {
  border: 1px dashed var(--border);
  border-radius: 8px;
  padding: 10px 12px;
  background: #fbfcfe;
  font-size: 14px;
}
.ai-head { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.ai-label { color: var(--muted); font-size: 12px; }
.ai-reason { margin: 6px 0 2px; }
.ai-evidence { margin: 2px 0; color: var(--muted); }
.ai-evidence code { color: var(--text); background: var(--bg); padding: 1px 4px; border-radius: 4px; }
.ai-limits { margin: 6px 0 0; padding-left: 18px; color: var(--warn); }
.ai-limits:empty { display: none; }
.ai-critique { margin: 6px 0 0; color: var(--muted); }
.ai-critique summary { cursor: pointer; }
.ai-critique p { margin: 4px 0 0; }

.teacher-controls { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; border-top: 1px solid var(--border); padding-top: 10px; min-width: 0; }
.teacher-controls select, .teacher-controls input {
  padding: 7px 9px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font: inherit;
  font-size: 13px;
  background: var(--surface);
  min-width: 0;
  max-width: 100%;
}
.teacher-controls select { flex: 1 1 240px; }
.teacher-controls .note { flex: 1 1 200px; min-width: 0; }
.actions { display: flex; gap: 8px; flex-wrap: wrap; min-width: 0; }

.pager { display: flex; align-items: center; justify-content: center; gap: 14px; padding: 18px 0; }
#page-info { color: var(--muted); font-size: 13px; }

.toast {
  position: fixed;
  left: 50%;
  bottom: 24px;
  transform: translateX(-50%) translateY(12px);
  padding: 10px 16px;
  border-radius: 8px;
  background: #1c2430;
  color: #fff;
  font-size: 14px;
  opacity: 0;
  pointer-events: none;
  transition: opacity .18s ease, transform .18s ease;
  z-index: 50;
}
.toast.show { opacity: .95; transform: translateX(-50%) translateY(0); }

@media (max-width: 640px) {
  .topbar, .toolbar, main { padding-left: 12px; padding-right: 12px; }
  .key { margin-left: 0; width: 100%; }
  .stat { min-width: 70px; }
}