h1 {
    font-size: 1.75em !important;
}

h2 {
    font-size: 1.5em !important;
}

h3 {
    font-size: 1.25em !important;
}

h4 {
    font-size: 1.1em !important;
}

.reveal .fragment.show-in,
.reveal .fragment.show-in-then-out,
.reveal .fragment.show-out.visible {
    display: none;
    visibility: hidden;
    opacity: 0;
}

.reveal .fragment.show-in.visible,
.reveal .fragment.show-in-then-out.current-fragment,
.reveal .fragment.show-out {
    display: block;
    visibility: visible;
    opacity: 1;
}

div.center {
    align-items: center;

    &> * {
        align-items: center;
    }
}

div.row {
    display: flex;
    justify-content: space-around;
    flex-direction: row;

    &> * {
        display: flex;
        justify-content: space-around;
        flex-direction: column;
    }
}

div.columns.center {
    display: flex;
    flex-direction: row;
    align-items: center;

    &> * {
        display: flex;
        flex-direction: column;
        align-items: center;
    }
}