.sidebar{width:280px;top:var(--header-height);height:calc(100vh - var(--header-height));background:var(--primary-background);flex-shrink:0;transition:width .2s;position:sticky;overflow:hidden auto}.sidebar-inner{width:280px;padding:var(--space-lg) var(--space-sm)}@media (width<=768px){.sidebar{top:var(--header-height);width:100%;z-index:var(--z-index-site-header);visibility:visible;transition:transform .2s,visibility;position:fixed;bottom:0;left:0;transform:translate(0)}.sidebar.closed{visibility:hidden;width:0;transition:transform .2s,visibility 0s .2s;transform:translate(-100%)}.sidebar-inner{width:100%}}.task{gap:var(--space-md);background:var(--tertiary-background);border-radius:var(--radius-md);padding:var(--space-lg);margin-bottom:var(--space-lg);flex-direction:column;display:flex}.task input:disabled{cursor:not-allowed}.task-actions{align-items:center;gap:var(--space-md);display:flex}.feedback{flex:1;min-width:0;min-height:1.5em;margin:0;font-weight:700}.feedback.correct{color:var(--success-color)}.feedback.incorrect{color:var(--danger-color)}.fieldset{border:none;margin:0;padding:0}.question{padding:0 var(--space-xs);font-weight:700}.option{align-items:center;gap:var(--space-sm);padding:var(--space-sm) var(--space-md);border:1px solid var(--quaternary-background);border-radius:var(--radius-md);cursor:pointer;display:flex}.option+.option{margin-top:var(--space-sm)}.option:has(input:disabled){cursor:not-allowed}.option:has(:focus-visible){outline:var(--border-focus);outline-offset:2px}.option input:focus-visible{outline:none}.prompt{line-height:var(--line-height-loose)}.blank{width:8em;margin:0 var(--space-xs);padding:.1em var(--space-xs);border:1px solid var(--quaternary-background);border-radius:var(--radius-sm);background:var(--primary-background);color:var(--primary-color);font:inherit;text-align:center;display:inline-block}.categorize{gap:var(--space-md);grid-template-columns:1fr 1.5fr;display:grid}.categorize-categories{gap:var(--space-md);display:grid}@media (width<=600px){.categorize{grid-template-columns:1fr}}.zone{border:1px solid var(--quaternary-background);border-radius:var(--radius-md);padding:var(--space-md);position:relative}.zone-heading{z-index:1;pointer-events:none;margin-bottom:var(--space-sm);font-size:var(--text-size-sm);position:relative}.zone-items{z-index:1;pointer-events:none;gap:var(--space-xs);min-height:2.5rem;margin-bottom:var(--space-sm);flex-direction:column;display:flex;position:relative}.item-row{pointer-events:auto;text-align:left;border:1px solid var(--quaternary-background);border-radius:var(--radius-sm);width:100%;padding:var(--space-xs) var(--space-sm);font:inherit;color:inherit;cursor:pointer;background:0 0;display:block}.item-row:not(:disabled):hover{background:var(--quaternary-background)}.item-row.selected{background:var(--quaternary-background);border-color:var(--highlight-color);font-weight:700}.item-row:disabled{cursor:not-allowed}.unshuffled .item-row{visibility:hidden}.zone-drop{z-index:0;border-radius:var(--radius-md);cursor:pointer;background:0 0;border:none;width:100%;height:100%;position:absolute;inset:0}.zone-drop.active:not(:disabled):hover{background:var(--quaternary-background)}.zone-drop:disabled{cursor:default}.order-list{gap:var(--space-xs);flex-direction:column;display:flex}.unshuffled .order-row{visibility:hidden}.order-row{align-items:center;gap:var(--space-sm);border:1px solid var(--quaternary-background);border-radius:var(--radius-sm);padding:var(--space-xs) var(--space-sm);display:flex}.order-position{min-width:1.5rem;font-weight:700}.order-text{flex:1;min-width:0}.order-controls{gap:var(--space-xs);display:flex}.order-controls button:disabled{cursor:not-allowed;opacity:.6}.listening-controls{align-items:center;gap:var(--space-sm);display:flex}.listening-transcript{padding:var(--space-sm) var(--space-md);border:1px solid var(--quaternary-background);border-radius:var(--radius-md);margin:0;font-style:italic}.word-builder-answer,.word-builder-pool{border:1px solid var(--quaternary-background);border-radius:var(--radius-md);padding:var(--space-md)}.zone-heading{margin-bottom:var(--space-sm);font-size:var(--text-size-sm)}.word-builder-row{gap:var(--space-sm);flex-wrap:wrap;min-height:2.5rem;display:flex}.unshuffled.word-builder-row{visibility:hidden}.word-builder-placeholder{color:var(--secondary-text);font-style:italic}.tile{min-height:44px;padding:var(--space-xs) var(--space-md);border:1px solid var(--quaternary-background);border-radius:var(--radius-sm);font:inherit;color:inherit;cursor:pointer;background:0 0;justify-content:center;align-items:center;display:inline-flex}.tile:not(:disabled):hover{background:var(--quaternary-background)}.tile:disabled{cursor:not-allowed}.tile-placed{border-color:var(--highlight-color);font-weight:700}.lesson-layout{display:flex}.lesson-layout .main{min-width:0;min-height:calc(100vh - var(--header-height));background:var(--secondary-background);flex:1;max-width:none;margin:0;padding:0}.lesson-content{max-width:720px;padding:var(--space-xl) var(--space-lg) var(--space-2xl);margin:0 auto}.lesson-next{justify-content:flex-end;display:flex}@media (width<=768px){.main.sidebar-open{visibility:hidden}}