right sidebar does not scroll when content is big

[chen19901225]

repo https://github.com/chen19901225/sphinx-example

when click 第106回__薄幸怨檀郎_往事已如烟如雾_温柔怜玉女_伊人真宜喜宜嗔 the page scroll to the content,but the right sidebar

does not scroll to menu.

[nineteendo]

It would be beneficial to link to an online example.