/* =========================================================================
   Dual-Task and Limited Capacity Laboratory — tool-specific styling
   -------------------------------------------------------------------------
   Shared page furniture comes from components/tool-kit.css. What is specific
   here is the two-part stimulus display, the two response rows and the
   task-cost chart.

   PRESENTATION SAFETY
   -------------------
   One display at a time, staying on screen until the learner answers. Only
   the two glyphs change; the panel, its size and its position stay put. No
   CSS animation or transition is used anywhere in this file, so there is
   nothing for a reduced-motion rule to switch off.
   ---------------------------------------------------------------------- */

/* Absolutely positioned visually-hidden <caption> elements have no positioned
   ancestor inside a scroller, which adds ~30px to the document's scrollable
   width at 320px. Candidate for components/tool-kit.css. */
.table-scroll {
  position: relative;
}

#dual .interactive__controls,
#dual .interactive__stage {
  min-width: 0;
}

@media (min-width: 52em) {
  #dual .interactive__body {
    grid-template-columns: minmax(0, 19rem) minmax(0, 1fr);
  }
}

#dual .control + .control {
  margin-top: var(--space-3);
}

.control--buttons {
  display: grid;
  gap: var(--space-2);
}

/* -------------------------------------------------------------------------
   The stimulus display
   -------------------------------------------------------------------------
   The number sits directly above the letter and both are centred, so neither
   task needs an eye movement to reach the other. That is deliberate: this
   laboratory is about competition for processing, not about scanning.
   ---------------------------------------------------------------------- */

.display {
  display: grid;
  gap: var(--space-2);
  align-content: center;
  justify-items: center;
  min-height: 11rem;
  padding: var(--space-4);
  border: 1px solid var(--colour-border);
  border-radius: var(--radius-md);
  background-color: var(--colour-surface);
}

.display__number,
.display__letter {
  margin: 0;
  font-family: var(--font-mono);
  line-height: 1;
  font-weight: 700;
  color: var(--colour-text);
  min-height: 1em;
  text-align: center;
}

.display__number {
  font-size: clamp(1.8rem, 6vw, 2.6rem);
  color: var(--colour-text-muted);
}

.display__letter {
  font-size: clamp(2.6rem, 9vw, 4rem);
}

.display__caption {
  margin: var(--space-3) 0 0;
  min-height: 2.5rem;
  font-size: var(--text-sm);
  color: var(--colour-text-muted);
  text-align: center;
}

/* -------------------------------------------------------------------------
   Responses
   -------------------------------------------------------------------------
   Two rows, one per task, always in the same order and always labelled in
   words. The key hint is decorative and hidden from assistive technology;
   each button carries an explicit accessible name.
   ---------------------------------------------------------------------- */

.responses {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  margin-top: var(--space-3);
}

.response {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  flex: 1 1 9rem;
  min-height: 3.25rem;
  font-size: var(--text-base);
  font-weight: 650;
}

.response[data-answered="yes"] {
  border-width: 2px;
  border-color: var(--colour-accent);
}

.response__key {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 700;
  padding: 0.1rem 0.4rem;
  border: 1px solid var(--colour-border-strong);
  border-radius: var(--radius-sm);
  color: var(--colour-text-muted);
}

.stage__form {
  display: grid;
  gap: var(--space-3);
  margin-top: var(--space-4);
}

.stage__form input[type="number"] {
  width: 100%;
  max-width: 9rem;
  min-height: 2.75rem;
  padding: 0.35rem 0.6rem;
  font: inherit;
  color: var(--colour-text);
  background-color: var(--colour-surface-raised);
  border: 1px solid var(--colour-border-strong);
  border-radius: var(--radius-sm);
}

/* -------------------------------------------------------------------------
   Cost chart
   -------------------------------------------------------------------------
   Four bars: each task alone and each task combined. The combined bars are
   hatched as well as differently filled, and every bar prints its own value.
   ---------------------------------------------------------------------- */

.dual-chart {
  max-width: 30rem;
}

.dual__bar--alone {
  fill: var(--colour-accent);
}

.dual__bar--dual {
  fill: var(--colour-cognitive);
}

.dual__hatch {
  stroke: var(--colour-surface);
  stroke-width: 3;
}

/* -------------------------------------------------------------------------
   Challenge
   ---------------------------------------------------------------------- */

.challenge select {
  width: 100%;
  min-width: 12rem;
  min-height: 2.75rem;
  padding: 0.35rem 0.6rem;
  font: inherit;
  font-size: var(--text-sm);
  color: var(--colour-text);
  background-color: var(--colour-surface-raised);
  border: 1px solid var(--colour-border-strong);
  border-radius: var(--radius-sm);
}

.challenge th[scope="row"] {
  min-width: 16rem;
  font-weight: 400;
}

.challenge__mark {
  display: block;
  margin-top: var(--space-1);
  font-size: var(--text-xs);
  color: var(--colour-text-muted);
}

/* -------------------------------------------------------------------------
   Forced colours
   ---------------------------------------------------------------------- */

@media (forced-colors: active) {
  .display {
    border: 1px solid CanvasText;
  }

  .response[data-answered="yes"] {
    border: 2px solid Highlight;
  }

  .response__key {
    border-color: ButtonText;
    color: ButtonText;
  }

  .dual__bar--alone {
    fill: CanvasText;
  }

  .dual__bar--dual {
    fill: Highlight;
  }

  .dual__hatch {
    stroke: Canvas;
  }

  .challenge select,
  .stage__form input[type="number"] {
    border: 1px solid ButtonText;
  }
}