:root {
  --bg: #f6f7f9; --card: #fff; --text: #1d2433; --muted: #5b6475; --line: #dde1e8;
  --primary: #1f5fbf; --primary-ink: #fff; --danger: #b42318; --ok-bg: #e7f6ec; --ok: #1e6b3a; --err-bg: #fdecea;
}
* { box-sizing: border-box; }
body { margin: 0; font: 16px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; background: var(--bg); color: var(--text); }
a { color: var(--primary); }
header.top { background: var(--card); border-bottom: 1px solid var(--line); }
header.top .wrap { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; padding-top: 10px; padding-bottom: 10px; }
header.top .brand { font-weight: 700; text-decoration: none; color: var(--text); margin-right: auto; }
header.top nav a { text-decoration: none; padding: 10px 8px; }
.wrap { max-width: 960px; margin: 0 auto; padding: 0 16px; }
main.wrap { padding-top: 16px; padding-bottom: 48px; }
h1 { font-size: 1.4rem; margin: 8px 0 16px; text-wrap: balance; }
h2 { font-size: 1.15rem; margin: 0 0 12px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 16px; margin-bottom: 16px; }
.muted { color: var(--muted); font-size: .92rem; }
.flash { padding: 10px 14px; border-radius: 8px; margin-bottom: 12px; background: var(--ok-bg); color: var(--ok); }
.flash.error { background: var(--err-bg); color: var(--danger); }
label { display: block; font-weight: 600; margin: 10px 0 4px; font-size: .95rem; }
input[type=text], input[type=number], input[type=password], input:not([type]), select, textarea {
  width: 100%; padding: 10px 12px; border: 1px solid var(--line); border-radius: 8px; font: inherit; background: #fff;
}
textarea { min-height: 90px; resize: vertical; }
.grid { display: grid; gap: 0 12px; grid-template-columns: 1fr; }
@media (min-width: 640px) { .grid.two { grid-template-columns: 1fr 1fr; } .grid.three { grid-template-columns: 1fr 1fr 1fr; } }
.btn, button { display: inline-flex; align-items: center; justify-content: center; min-height: 44px; padding: 8px 16px;
  border-radius: 8px; border: 1px solid var(--primary); background: var(--primary); color: var(--primary-ink);
  font: inherit; font-weight: 600; text-decoration: none; cursor: pointer; }
.btn.ghost, button.ghost { background: #fff; color: var(--primary); }
.btn.danger, button.danger { background: #fff; color: var(--danger); border-color: var(--danger); }
.btn.small, button.small { min-height: 36px; padding: 4px 10px; font-size: .9rem; }
.actions { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; margin-top: 12px; }
form.inline { display: inline; }
table { width: 100%; border-collapse: collapse; }
th, td { text-align: left; padding: 8px 6px; border-bottom: 1px solid var(--line); vertical-align: top; }
th { font-size: .9rem; color: var(--muted); }
.num { font-variant-numeric: tabular-nums; }
.list { list-style: none; margin: 0; padding: 0; }
.list li { padding: 10px 0; border-bottom: 1px solid var(--line); display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.list li .grow { flex: 1 1 200px; }
.q { border-top: 1px solid var(--line); padding: 12px 0; }
.q .meta { display: flex; gap: 8px; flex-wrap: wrap; font-size: .88rem; color: var(--muted); margin-top: 4px; }
.badge { display: inline-block; padding: 1px 8px; border-radius: 99px; background: #eef2f8; color: var(--text); font-size: .85rem; }
.badge.ans { background: var(--ok-bg); color: var(--ok); font-weight: 600; }
.opts { margin: 6px 0 0; padding-left: 20px; }
.opts li.correct { font-weight: 700; color: var(--ok); }
details > summary { cursor: pointer; font-weight: 600; min-height: 44px; display: flex; align-items: center; }
.row-edit { display: grid; gap: 6px; grid-template-columns: 70px 1fr; align-items: center; }
@media (min-width: 640px) { .row-edit { grid-template-columns: 70px 1fr 130px auto; } }
.tf-row { display: grid; grid-template-columns: 1fr auto; gap: 8px; align-items: center; margin-bottom: 8px; }
.tf-row fieldset { border: 0; margin: 0; padding: 0; display: flex; gap: 10px; }
.tf-row fieldset label, .choice label { display: inline-flex; gap: 4px; align-items: center; font-weight: 500; margin: 0; min-height: 44px; }
.choice { display: flex; gap: 14px; flex-wrap: wrap; }
.scroll { overflow-x: auto; }
@media print {
  header.top, .no-print { display: none !important; }
  body { background: #fff; }
  .card { border: 0; padding: 0; }
}
.badge.ai { background: #fff4e5; color: #8a4b00; font-weight: 600; }
.ai-more { display: grid; grid-template-columns: 1fr 1fr; gap: 8px 12px; align-items: end; margin-top: 12px;
  padding-top: 12px; border-top: 1px dashed var(--line); }
.ai-more button { grid-column: 1 / -1; }
@media (min-width: 640px) { .ai-more { grid-template-columns: 120px 140px auto; } .ai-more button { grid-column: auto; } }
.ai-more label { margin-top: 0; }
table.structure input { padding: 6px 8px; }
.visually-hidden { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0 0 0 0); white-space: nowrap; border: 0; }
.error-text { color: var(--danger); }
.answer-row { display: grid; grid-template-columns: 64px 1fr; gap: 8px; align-items: center; padding: 10px 0;
  border-top: 1px solid var(--line); }
.answer-row .controls { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.answer-row select, .answer-row input { width: auto; min-width: 72px; }
.flagged { background: #fff8eb; }
.visually-hidden:focus-visible + label { outline: 3px solid var(--primary); outline-offset: 2px; }