Per [1] it sounds like it should be usable with "position: fixed". Though I can't test it right now.

There's some interesting (hopefully not outdated) discussion in the Chromium bug here [2][3] which helps explain why things the way they are (balancing several competing constraints).

[1] https://developers.google.com/web/updates/2016/12/url-bar-re... [2] https://bugs.chromium.org/p/chromium/issues/detail?id=428132 [3] https://github.com/bokand/URLBarSizing