.collapse-content-wrapper {
    position: relative;
}
.collapse-content {
    overflow: hidden;
    transition: max-height 0.5s ease;
    -webkit-mask-image: linear-gradient(
        to bottom, 
        black 0%,
        black 80%,
        transparent 100%
    );
    mask-image: linear-gradient(
        to bottom, 
        black 0%,
        black 80%,
        transparent 100%
    );
}
.collapse-content-toggle{
    display: inline-block;
}        
.collapse-content.expanded{
    -webkit-mask-image: none;
    mask-image: none;  
}
.toggle-collapse,
.toggle-expand {
    display: none;
}
.collapse-content-toggle.expanded .toggle-collapse{
    display: block;
}
.collapse-content-toggle:not(.expanded) .toggle-expand{
    display: block;
}