This guide is for the embed app at rate.tapchiphowall.com (a separate Nuxt project). It explains how to make the embed report its content height to the parent (tapchiphowall.com / en.tapchiphowall.com) so the parent's <iframe> resizes correctly when content inside the embed changes (tab switches, async data loads, etc.).
Browsers enforce same-origin policy: tapchiphowall.com cannot read the height of an iframe served from rate.tapchiphowall.com. The parent has no way to detect content reflows inside the embed unless the embed cooperates by posting its current height via window.parent.postMessage(...).
Polling from the parent only works if the embed responds to height-request messages. The cleanest fix is for the embed to push height updates whenever its own content changes — no polling required.