/* Same palette and typography as the accepted duet homepage. */
.catalog-group summary > .catalog-icon { flex: 0 0 32px; width: 32px; height: 32px; color: var(--green); margin-right: 14px; }
.catalog-group summary > span { flex: 1; min-width: 0; }
.subject-dialog { margin: auto; max-width: calc(100% - 20px); }
.course-link > .catalog-icon { flex: 0 0 24px; width: 24px; height: 24px; color: var(--green); margin-right: 12px; }
.course-link > span:first-of-type { flex: 1; min-width: 0; }
.icon-accent { stroke: var(--secondary, #c33c33); }
.promo-lesson { padding: 24px 28px 28px; }
.promo-progress { display: flex; gap: 16px; list-style: none; padding: 0; margin: 0 0 28px; color: var(--muted); font-size: 13px; }
.promo-progress li { display: flex; gap: 7px; align-items: center; }
.promo-progress span { display: inline-grid; place-items: center; border: 1px solid var(--border); width: 25px; height: 25px; border-radius: 50%; flex: 0 0 25px; }
.promo-progress [aria-current] { color: var(--accent); font-weight: 600; }
.promo-progress [aria-current] span { background: var(--accent); color: white; border-color: var(--accent); }
.promo-lesson h3 { font-size: 28px; line-height: 1.2; letter-spacing: -.7px; margin: 0 0 16px; }
.promo-task { font-size: 17px; line-height: 1.55; margin: 0 0 22px; }
.promo-model { display: block; width: 100%; max-height: 230px; overflow: visible; color: var(--accent); fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.promo-model text { stroke: none; fill: var(--ink); font: 15px Onest, sans-serif; text-anchor: middle; }
.promo-model .model-number { font-size: 32px; }
.promo-model .model-caption { font-size: 12px; fill: var(--muted); }
.promo-model .model-fill { fill: var(--accent); stroke: var(--accent); }
.promo-model .model-secondary { fill: var(--secondary); stroke: var(--secondary); }
.promo-model .model-axis { stroke: var(--border); }
.promo-model .mean-line { stroke: var(--secondary); stroke-dasharray: 5 5; }
.promo-formula { font: 25px/1.5 Georgia, serif; text-align: center; margin: 16px 0; }
.promo-formula strong { color: var(--accent); }
.model-legend { font-size: 14px; text-align: center; color: var(--muted); }
.fraction-sector { fill: var(--mint); stroke: var(--accent); stroke-width: 1.5; cursor: pointer; }
.fraction-sector.selected { fill: var(--accent); }
.promo-lesson[data-solved="true"] .fraction-sector { pointer-events: none; }
.sector-controls, .promo-choices { display: flex; flex-wrap: wrap; gap: 10px; margin: 20px 0; }
.sector-controls button, .promo-choices button { background: white; color: var(--ink); padding: 11px 16px; min-height: 44px; border: 1px solid var(--border); border-radius: 8px; font: 15px/1.4 Onest, sans-serif; cursor: pointer; }
.sector-controls [aria-pressed="true"], .promo-choices [aria-pressed="true"] { border-color: var(--accent); color: var(--accent); background: var(--mint); box-shadow: inset 0 0 0 1px var(--accent); }
.promo-feedback { font-size: 16px; line-height: 1.55; padding: 16px 18px; border-radius: 8px; background: var(--mint); margin: 20px 0; }
.promo-feedback:empty { display: none; }
.promo-feedback.wrong { background: #fff1ef; color: #92302a; }
.promo-actions { display: flex; gap: 18px; align-items: center; flex-wrap: wrap; margin-top: 24px; border-top: 1px solid var(--border); padding-top: 22px; }
.promo-actions .button { font-size: 16px; }
.promo-hint, .promo-utility { font: 14px/1.5 Onest, sans-serif; color: var(--muted); background: transparent; border: 0; padding: 10px 0; min-height: 44px; text-decoration: underline; text-underline-offset: 4px; cursor: pointer; }
.promo-utility:disabled { opacity: .5; cursor: default; }
.promo-course { margin-top: 16px; }
.python-console { background: var(--mint); border-radius: 8px; padding: 16px 20px; margin-top: 12px; }
.python-console span { font-size: 12px; color: var(--muted); }
.python-console pre { font: 17px/1.6 ui-monospace, monospace; min-height: 70px; margin: 10px 0 0; white-space: pre-wrap; }
.experiment-controls { display: flex; align-items: center; justify-content: center; flex-wrap: wrap; gap: 24px; }
.experiment-controls output { min-width: 65px; font-variant-numeric: tabular-nums; color: var(--muted); font-size: 14px; }
.pendulum-string { stroke: var(--ink); }
.logic-scroll { overflow-x: auto; }
.logic-table { border-collapse: collapse; width: 100%; font-size: 14px; }
.logic-table caption { text-align: left; color: var(--muted); margin-bottom: 12px; }
.logic-table th { font-weight: 500; padding: 12px 6px; }
.logic-table td { border: 1px solid var(--border); text-align: center; padding: 0; }
.logic-table button { display: block; width: 100%; min-height: 48px; border: 0; background: white; color: var(--muted); font: 20px Onest, sans-serif; cursor: pointer; }
.logic-table [aria-pressed="true"] { background: var(--mint); color: var(--accent); font-weight: 600; }
.training-set { padding: 16px 20px; background: var(--mint); border-radius: 8px; }
.training-set p { font-size: 16px; line-height: 1.5; margin: 6px 0; }
.training-set p:first-child { font-size: 12px; color: var(--muted); margin-bottom: 10px; }
.training-set strong { color: var(--accent); font-weight: 500; }
.wire { stroke: var(--border); stroke-width: 4; }
.wire.active { stroke: var(--accent); }
.gate-shape { fill: var(--mint); stroke: var(--accent); }
.bulb { fill: white; stroke: var(--muted); }
.bulb.lit { fill: #fff1dc; stroke: var(--secondary); }
.promo-lesson[data-promo="technology"][data-phase="2"] .bulb { stroke-dasharray: 3 3; opacity: .5; }
.promo-lesson .gate-inputs { justify-content: center; }
.promo-lesson .gate-inputs label { min-height: 44px; display: flex; align-items: center; gap: 8px; cursor: pointer; }
.number-track { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; padding: 24px 0; font-size: 26px; }
.number-track span { min-width: 52px; height: 52px; display: grid; place-items: center; background: var(--mint); color: var(--accent); border-radius: 50%; }
.number-track i { font-size: 16px; font-style: normal; color: var(--muted); }
@media(max-width:540px) {
  .promo-lesson { padding: 20px 16px; }
  .promo-progress { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 9px; font-size: 11px; margin-bottom: 24px; }
  .promo-progress li { gap: 6px; flex-direction: column; text-align: center; min-width: 0; }
  .promo-progress span { width: 20px; height: 20px; flex-basis: 20px; }
  .promo-lesson h3 { font-size: 25px; }
  .promo-task { font-size: 16px; }
  .promo-actions { gap: 8px 18px; }
  .promo-actions .button { width: 100%; text-align: center; }
  .sector-controls button { padding: 10px 12px; }
  .number-track { gap: 7px; font-size: 22px; }
  .number-track span { min-width: 44px; height: 44px; }
}