.matmat-cat-panel{overflow:hidden;max-height:0;transition:max-height 250ms ease}.matmat-cat-toggle .matmat-icon-minus{display:none}.matmat-cat-card.is-open .matmat-cat-toggle .matmat-icon-plus{display:none}.matmat-cat-card.is-open .matmat-cat-toggle .matmat-icon-minus{display:inline}