swc/crates/swc_css_prefixer/tests/fixture/keyframes/input.css

@keyframes anim {
    from {
        top: calc(10% + 10px);
        transform: rotate(10deg)
    }
    50% {
        top: 0;
        display: flex
    }
    to {
        top: calc(10%);
        transform: rotate(0)
    }
}

@media screen {
    @keyframes inside {}
}

@keyframes spaces { from { color: black } to { color: white } }