CSS

Hi,

after installation, the CSS of our wiki has not been applied(:cry:)
If I apply some theme to it, any change does not occur.

Here, I refer to my wilki's URL.
http://rolland.sfc.keio.ac.jp/tec/themes/admin/admin_themes_manager.php

I need your help.

Thanks,

Of cause I'd need to log in to see the admin stuff ;)
What is the problem - you just select a theme that you like and then modify if you want. What you WILL need to do is wipe the caches if you are changing things on a theme that is being used. Wipe the browser cache, and Admin->kernel->SystemCache

I appriciate for your kindness!
I wiped the SystemCashe, but the problem is not solved...
Although I can change the theme to a new one on Themes Manager, this change turns back after I move to another page.

You should be seeing a yes/no popup after selecting a different theme. Until you accept the change it will not 'stick'
It's useful when we make changes to a theme that simply do not work so need to get back to a working one ;)