User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:62.0) Gecko/20100101 Firefox/62.0 Build ID: 20180519100118 Steps to reproduce: Visit https://jsfiddle.net/pjvutnq0/ and follow "Navigate to the fragment" link. Actual results: Left border edge of the fragment element is on the left edge of viewport. Expected results: Right border edge of the fragment element is on the right edge of viewport. According to HTML spec[1] and CSSOM View spec[2], the right edge is the beginning edge in "writing-mode: vertical-rl" document. [1] https://html.spec.whatwg.org/multipage/browsing-the-web.html#scroll-to-the-fragment-identifier [2] https://drafts.csswg.org/cssom-view/#scroll-an-element-into-view HTML spec refers to an obsolete argument of CSSOM View spec. There are pull requests for HTML spec[3] and web-platform-test[4]. [3] https://github.com/whatwg/html/pull/3131 [4] https://github.com/w3c/web-platform-tests/pull/10828

Google Chrome has the same issue: https://bugs.chromium.org/p/chromium/issues/detail?id=844868 MS Edge works as expected.

Duplicate of bug 1102175?

Bug 1102175 is about principal writing mode[1] and happens when "writing-mode: vertical-rl" is applied to a body element. [1] https://drafts.csswg.org/css-writing-modes-3/#principal-flow This bug happens also when "writing-mode: vertical-rl" is applied to a html element.