let polyfillPromise; const supportsAnchorPositioning = ()=>'anchorName' in document.documentElement.style; const afterInitialRender = ()=>new Promise((resolve)=>{ requestAnimationFrame(()=>{ requestAnimationFrame(resolve); }); }); export const bootstrapAnchorPositioningPolyfill = ()=>{ if(supportsAnchorPositioning()) return Promise.resolve(false); if(polyfillPromise) return polyfillPromise; polyfillPromise = afterInitialRender() .then(async ()=>{ const { default: polyfill } = await import('@oddbird/css-anchor-positioning/fn'); await polyfill(); return true; }) .catch((error)=>{ polyfillPromise = undefined; throw error; }); return polyfillPromise; };