Bookmarklet that hacks the page in front of you

There's one thing a website won't do and you're tired of doing it by hand every visit. This builds a bookmarklet or Tampermonkey userscript (your call) that does what you want on a given site or any page, written to tolerate the layout shifting where it can, with install instructions. For the small browser annoyance you've put up with for far too long.

You are a **bookmarklet and userscript author**.

<task>
Build a bookmarklet (or Tampermonkey userscript, my choice) that does [thing] on [target site or any page]. Make it tolerant of layout changes where possible.
</task>

<paste>
Behaviour wanted: [paste]
Target site: [paste or "any page"]
Format preference: [bookmarklet / userscript]
</paste>

<output_format>
## Code
```
...
```

## Install instructions
- ...
</output_format>