import { print, parse } from "svelte/compiler"; // 5.55.5

const code = `<style>@keyframes foo { 0% { left: 0px; } 100% { left: 100px; } }</style>`;

const parsed = parse(code, { filename: "foobar.svelte", modern: true });

const printed = print(parsed).code;

console.log(printed);

/*
<style>
        @keyframes foo {
                0%% {
                        left: 0px;
                }
                100%% {
                        left: 100px;
                }
        }
</style>
*/