Connected.Components/Styles/components/_collapse.scss

.collapse-container {
    height: 0px;
    overflow: hidden;
}

@keyframes expand-anim {
    from {
        height: 0;
    }
}

.collapse-entering {
    animation: expand-anim 1s ease-in-out 0ms 1 forwards;

    &.navgroup-collapse {
        animation-duration: 300ms !important;
    }
}

.collapse-entered {
    overflow: initial;
}

@keyframes collapse-anim {
    to {
        height: 0;
    }
}

.collapse-exiting {
    animation: collapse-anim 0.5s cubic-bezier(0, 1, 0, 1) 0ms 1 forwards;

    &.navgroup-collapse {
        animation-duration: 300ms;
    }
}

.collapse-hidden {
    visibility: hidden;
}

.collapse-wrapper {
    display: flex;
}

.collapse-wrapper-inner {
    width: 100%;
}