discardOverridden

Removes at-rules which have the same identifier as another; for example two instances of @keyframes one. As the browser will only count the last of these declarations, all others can safely be removed.

@keyframes one {
    0% {
        opacity: 1;
    }
    to {
        opacity: 0;
    }
}
@keyframes one {
    0% {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(359deg);
    }
}
.box {
    animation-name: one;
}
@keyframes one {
    0% {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(359deg);
    }
}
.box {
    animation-name: one;
}

Latest release v4.0.0-rc.0 · Changelog · Distributed under the MIT License.