css/core.css do not load on server

I am learning to design a single page wp website. Everything works fine on local server and the css/core.css and css/reset.css loads fine. But it don’t load on server after I uploaded. In fact, it even can’t be accessed by typing the url directly like this: http://domain.com/blog/wp-content/themes/theme-name/css/core.css. While I could access other theme’s css like: http://domain.com/blog/wp-content/themes/starkers/style/css/reset.css
Permission has been set to like other css files.

So, what’s the problem? Thanks in advance for help. This is my first time posting here.