[Orgmode] How to align tag to the right margin

[Chao LU]

Dear all,

Got another question, as titled, how to align tag to the right margin? My org tag look like below:

|*** blablabalblablab                       :Book:Doc:EBook:STAR5:                    |

|                                                                                                              |
                                                                                         ---------------------

                                                                                                 |
                                                                                                 ---------------------------->There's some blank between the tags and the right boundary of Emacs.

Thanks in advance.

Chao