/* Dual N-Back — its own styles (the shared ones are core/tools.css). Scoped .chqt-nb*. */
.chqt-nb-stage { display: flex; flex-direction: column; align-items: center; gap: 10px; padding: 14px; border-radius: 14px; border: 2px solid var(--chqt-line); background: #0F1714; color: #fff; }
.chqt-nb-grid { display: grid; grid-template-columns: repeat(3, 72px); grid-template-rows: repeat(3, 72px); gap: 8px; }
.chqt-nb-grid span { display: flex; align-items: center; justify-content: center; border-radius: 12px; border: 2px solid #3d4a45; background: #1f2b27; font-size: 30px; font-weight: 800; color: #0F1714; }
.chqt-nb-grid span[data-lit="1"] { background: #F2C94C; border-color: #F2C94C; }
.chqt-nb-grid .chqt-nb-mid { border-color: transparent; background: transparent; color: #8fa39b; font-size: 16px; font-weight: 600; font-variant-numeric: tabular-nums; }
.chqt-nb-status { margin: 0; font-size: 15px; text-align: center; opacity: .9; min-height: 42px; }
.chqt-nb-keys { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.chqt-nb-key { min-height: 56px; border-radius: 12px; border: 2px solid var(--chqt-accent); background: #fff; color: var(--chqt-ink); font-size: 18px; font-weight: 700; cursor: pointer; -webkit-tap-highlight-color: transparent; touch-action: manipulation; }
.chqt-nb-key kbd { font: inherit; font-size: 13px; font-weight: 600; color: var(--chqt-muted); margin-left: 4px; }
.chqt-nb-key[aria-pressed="true"] { background: var(--chqt-accent); color: #fff; }
.chqt-nb-key[aria-pressed="true"] kbd { color: #fff; }
.chqt-nb-start { width: 100%; margin-bottom: 10px; }
.chqt-nb-set summary { cursor: pointer; font-weight: 600; min-height: 44px; display: flex; align-items: center; list-style: none; }
.chqt-nb-set summary::-webkit-details-marker { display: none; }
.chqt-nb-set summary::before { content: '+'; display: inline-block; width: 22px; font-weight: 700; color: var(--chqt-accent); }
.chqt-nb-set[open] summary::before { content: '−'; }
.chqt-nb-lines { margin: 4px 0 8px; padding-left: 20px; font-size: 16px; }
.chqt-nb-h3 { font-size: 16px; margin: 14px 0 8px; }
.chqt-nb-history { list-style: none; margin: 0 0 8px; padding: 0; font-size: 15px; }
.chqt-nb-history li { display: flex; justify-content: space-between; gap: 10px; padding: 7px 0; border-top: 1px solid var(--chqt-line); }
.chqt-nb-history li span:last-child { color: var(--chqt-muted); text-align: right; }
.chqt-nb-find { margin: 0; padding-left: 18px; font-size: 14.5px; line-height: 1.45; }
.chqt-nb-find li { margin-bottom: 8px; }
.chqt-nb-med { margin-top: 6px; }
@media (max-width: 460px) { .chqt[data-tool="dual-n-back"] .chqt-lede { display: none; } }
@media (max-width: 420px) { .chqt-nb-stage { padding: 8px; gap: 4px; } .chqt-nb-grid { grid-template-columns: repeat(3, 52px); grid-template-rows: repeat(3, 52px); gap: 6px; } .chqt-nb-status { min-height: 0; font-size: 14px; } .chqt-nb-key { min-height: 50px; } }