/** Marks the document root with the host platform so shared Web UI CSS can scope desktop-only rules. */ /** * Sets `data-platform` (e.g. `darwin`) on ``, deferring to DOMContentLoaded * when the preload runs before the document root exists. */ export function markDocumentPlatform(): void { const mark = (): void => { document.documentElement.dataset.platform = process.platform } // lib.dom types documentElement non-null, but a preload runs before the // document root exists. const root = document.documentElement as HTMLElement | null if (root === null) window.addEventListener('DOMContentLoaded', mark) else mark() }