1. Marker (test123) in, submit — the value shows up in the page tab title.
2. Devtools: hover the marker in Elements — you're inside <title>.
3. Same raw-text zone as the textarea: HTML inside the tag won't execute.
4. Close the context first, payload second.

https://stuxnet.pro/xss/lab7/index.php?name=</title><script>alert(3)</script>

Fires on page load by itself. It's the same "leave the raw-text element first" rule as Lab 6 — contexts differ, the principle doesn't.