/* Instrument lesson additions use the shared lesson layout and color tokens. */
.instrument-comparison { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; margin: 24px 0; }
.instrument-comparison > div { padding: 20px; border: 1px solid var(--line); border-radius: 12px; background: var(--fd-sage); }
.instrument-comparison h3 { margin-top: 0 !important; }
.instrument-comparison p { margin-bottom: 0; }
.instrument-control-loop { list-style: none; padding: 0; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; margin: 24px 0; }
.instrument-control-loop li { padding: 18px; border: 1px solid var(--line); border-radius: 12px; background: var(--fd-sage); }
.instrument-control-loop strong { display: block; color: var(--teal); font-size: 21px; margin-bottom: 8px; }
.instrument-control-loop span { font-size: 16px; line-height: 1.6; }
.instrument-exercise { margin-top: 28px; padding-top: 20px; border-top: 1px solid var(--line); }
.instrument-exercise fieldset { min-width: 0; margin: 24px 0; padding: 18px; border: 1px solid var(--line); border-radius: 12px; }
.instrument-exercise legend { max-width: 100%; padding: 0 8px; font-weight: 700; color: var(--teal); font-size: 18px; }
.instrument-exercise fieldset p { margin-top: 4px; }
.instrument-exercise label { display: flex; align-items: flex-start; gap: 10px; min-height: 44px; padding: 12px; margin-top: 8px; border: 1px solid var(--line); border-radius: 8px; cursor: pointer; font-size: 16px; line-height: 1.5; }
.instrument-exercise label:has(input:checked) { background: var(--fd-sage); border-color: var(--teal); }
.instrument-exercise input { flex: 0 0 auto; width: 18px; height: 18px; margin: 3px 0 0; accent-color: var(--teal); }
.instrument-exercise label:focus-within { outline: 3px solid var(--teal); outline-offset: 3px; }
.instrument-exercise-actions { display: flex; gap: 12px; flex-wrap: wrap; }
.instrument-exercise-actions button { min-height: 44px; padding: 10px 16px; border: 1px solid var(--teal); border-radius: 8px; color: white; background: var(--teal); font: inherit; cursor: pointer; }
.instrument-exercise-actions button[type=button] { background: white; color: var(--teal); }
.instrument-exercise-actions button:disabled { opacity: .5; cursor: default; }
.instrument-exercise-actions button:focus-visible { outline: 3px solid var(--teal); outline-offset: 3px; }
.instrument-exercise-feedback { margin-top: 20px; padding: 16px; border: 1px solid var(--line); border-radius: 12px; background: var(--fd-sage); }
.instrument-exercise-feedback li, .instrument-exercise-key li { margin-bottom: 14px; }
.instrument-exercise-key { margin-top: 20px; }
.instrument-lesson .instrument-figure, .instrument-lesson .instrument-diagram { margin: 24px 0; padding: 16px; border: 1px solid var(--line); border-radius: 12px; background: white; }
.instrument-lesson .instrument-figure svg, .instrument-lesson .instrument-diagram svg { display: block; width: 100%; max-width: 720px; height: auto; margin: auto; }
.instrument-lesson figcaption { margin-top: 12px; font-size: 15px; line-height: 1.6; color: var(--muted); }
.instrument-lesson .instrument-table { max-width: 100%; overflow-x: auto; margin: 24px 0; border: 1px solid var(--line); border-radius: 10px; }
.instrument-lesson .instrument-table table { width: 100%; border-collapse: collapse; margin: 0; font-size: 16px; }
.instrument-lesson .instrument-table th, .instrument-lesson .instrument-table td { padding: 12px; vertical-align: top; text-align: left; border-bottom: 1px solid var(--line); }
.instrument-lesson .instrument-table th { background: var(--fd-sage); }
.instrument-lesson .instrument-table:focus-visible { outline: 3px solid var(--teal); outline-offset: 3px; }
.instrument-lesson .instrument-callout { padding: 16px 20px; margin: 24px 0; border-left: 4px solid var(--teal); background: var(--fd-sage); }
.instrument-lesson .result-marks { flex-wrap: wrap; }
.instrument-lesson .source-list, .instrument-lesson .reference { overflow-wrap: anywhere; }
.instrument-practice-history { margin-top: 24px; padding-top: 16px; border-top: 1px solid var(--line); }
.instrument-practice-history button { min-height: 44px; padding: 10px 14px; font: inherit; border: 1px solid var(--teal); border-radius: 8px; background: white; color: var(--teal); cursor: pointer; }
.instrument-practice-history button:disabled { opacity: .6; cursor: default; }
.instrument-practice-history button:focus-visible { outline: 3px solid var(--teal); outline-offset: 3px; }
.instrument-history-details { margin-top: 18px; }
.instrument-history-details summary { min-height: 44px; cursor: pointer; font-weight: 700; }
.instrument-history-details li { margin-bottom: 18px; }
.instrument-history-details li p { margin: 6px 0; }
.instrument-history-details time { font-size: 14px; color: var(--muted); }
/* Figures with long labels scroll within the lesson on small screens. */
.instrument-svg-scroll { max-width: 100%; overflow-x: auto; }
.instrument-lesson .instrument-svg-scroll svg { min-width: 540px; }
.instrument-svg-scroll:focus-visible { outline: 3px solid var(--teal); outline-offset: 3px; }
.instrument-trainer { margin: 28px 0; padding: 20px; border: 1px solid var(--line); border-radius: 12px; background: white; }
.instrument-trainer-views { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 20px; align-items: start; }
.instrument-trainer-views figure { margin: 0; }
.instrument-trainer svg { width: 100%; height: auto; display: block; }
.instrument-trainer svg text { font: 15px system-ui,sans-serif; }
.instrument-trainer-explanation h4 { margin-top: 16px; }
.instrument-trainer-readouts { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 12px; }
.instrument-trainer-readouts > div { padding: 12px; background: var(--fd-sage); border-radius: 8px; }
.instrument-trainer-readouts dt { font-size: 14px; color: var(--muted); }
.instrument-trainer-readouts dd { margin: 4px 0 0; font-weight: 700; }
.instrument-trainer-controls { min-width: 0; padding: 16px; margin-top: 24px; border: 1px solid var(--line); border-radius: 8px; display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 16px; }
.instrument-trainer-controls legend { padding: 0 8px; font-weight: 700; }
.instrument-trainer-controls label { display: flex; flex-direction: column; gap: 4px; font-size: 16px; }
.instrument-trainer-controls input { width: 100%; min-height: 44px; accent-color: var(--teal); }
.instrument-trainer-controls select { min-height: 44px; width: 100%; font: inherit; padding: 8px; border: 1px solid var(--line); border-radius: 6px; }
.instrument-trainer-controls input:focus-visible, .instrument-trainer-controls select:focus-visible { outline: 3px solid var(--teal); outline-offset: 3px; }
.instrument-trainer-actions { grid-column: 1/-1; display: flex; flex-wrap: wrap; gap: 12px; }
.instrument-trainer-actions button { min-height: 44px; padding: 10px 14px; font: inherit; background: white; color: var(--teal); border: 1px solid var(--teal); border-radius: 8px; cursor: pointer; }
.instrument-trainer-actions button:disabled { opacity: .6; cursor: default; }
.instrument-trainer-actions button:focus-visible { outline: 3px solid var(--teal); outline-offset: 3px; }
.instrument-model-note { font-size: 15px; color: var(--muted); }
@media (max-width: 650px) {
  .instrument-comparison, .instrument-control-loop, .instrument-trainer-views, .instrument-trainer-controls { grid-template-columns: 1fr; }
  .instrument-lesson .instrument-table::before { content: "Scroll horizontally if needed →"; display: block; position: sticky; left: 0; padding: 8px 12px; font-size: 13px; color: var(--muted); background: var(--fd-sage); }
  .instrument-svg-scroll::before { content: "Scroll diagram horizontally →"; display: block; position: sticky; left: 0; padding-bottom: 8px; font-size: 13px; color: var(--muted); }
  .instrument-lesson .practice-controls { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .instrument-lesson .practice-controls button:first-child { justify-self: start; }
  .instrument-lesson .practice-controls button:last-child { justify-self: end; }
  .instrument-lesson .card-position { grid-column: 1 / -1; grid-row: 2; justify-content: center; flex-wrap: wrap; }
  .instrument-trainer { padding: 12px; }
  .instrument-exercise fieldset { padding: 12px; }
  .instrument-lesson .instrument-figure, .instrument-lesson .instrument-diagram { padding: 8px; }
}
@media print {
  .instrument-exercise form { display: none; }
  .instrument-exercise-key { display: block; }
  .instrument-comparison > div, .instrument-control-loop li { break-inside: avoid; }
  .instrument-lesson .instrument-table, .instrument-svg-scroll { overflow: visible; }
  .instrument-lesson .instrument-svg-scroll svg { min-width: 0; }
  .instrument-trainer-controls, .instrument-practice-history button { display: none; }
  .instrument-trainer-views { display: block; }
}