The DEMO version only includes 4 pages:
http://kientrucau.com
http://kientrucau.com/p/cong-ty-thiet-ke-kien-truc.html
http://kientrucau.com/p/dich-vu-thiet-ke-kien-truc.html
http://kientrucau.com/p/tu-van-thiet-ke-kien-truc.html

It is possible to download these free files and install them on your server, so you can test how the site works.
Visit https://www.waybackmachinedownloader.com/en/buy-wayback-machine-downloader-recover/ to buy a fully functioning site.
Go back to the index page