swc/crates/swc_css_parser/tests/fixture/at-rule/keyframe/input.css

@keyframes foo { /* ... */ }
@keyframes "foo" { /* ... */ }
@keyframes    foo    { /* ... */ }

@keyframes slidein {
    from {
        transform: translateX(0%);
    }

    to {
        transform: translateX(100%);
    }
}

@keyframes identifier {
    0% { top: 0; left: 0; }
    30% { top: 50px; }
    68%, 72% { left: 50px; }
    100% { top: 100px; left: 100%; }
}

@keyframes FOO {}
@keyframes "initial" {}
@keyframes "None" {}
@keyframes slide-right {

    from {
        margin-left: 0px;
    }

    50% {
        margin-left: 110px;
        opacity: 1;
    }

    50% {
        opacity: 0.9;
    }

    to {
        margin-left: 200px;
    }

}

@keyframes slidein-up {
    fRoM {
        transform: translateX(0%);
    }

    tO {
        transform: translateX(100%);
    }
}