SIHU widget — embed test harness

This page is a test harness, not a product page.

Its CSS is intentionally hostile — content-box sizing, Comic Sans, 22px/3 type, and !important overrides on every button, textarea and svg. The floating widget in the bottom-right corner lives in a shadow root, so none of it should reach inside. Equally, nothing the widget defines should change this page.

Console handles: SihuChat.open(), SihuChat.close(), SihuChat.toggle(), SihuChat.send("hello"), SihuChat.destroy().

To test the position: fixed containing-block trap, run document.body.style.transform = "translateZ(0)" and reload.