#performances li.glide__slide > div {
    height: 90vh;
    background-position: center center;
    background-size: cover;
}

@media (max-width: 760px)
{
    #performances h2 {
        font-size: 1.5em;
    }
}

@media (max-width: 515px)
{
    #performances h2 {
        font-size: 1em;
    }
}