Opera with Chinese font config

First, you need to have YaHei font, which I think can give you best profile when Chinese+English is showing. I even use it as the font in terminal. I think it is better than WenQuanYi.
Methods of installing YaHei is in another post of mine.

1. Tools->Preferences->advanced->fonts; all change to YaHei Consolas Hybrid.
2. type opera:config in address bar, search antialiasing and dismark it.
3. open a terminal, type:
echo 'html,body,*{font-family:"YaHei Consolas Hybrid" !important;}' > ~/.opera/styles/user/user.css
4. restart opera, view->style->user.css.
tools->preferences->general->language->details->encoding to assume...->gb18030
5. restart opera.
You will find the Chinese font is perfect.