jekyll work in local but not work github. unreadable: minima

My Code. https://github.com/shingo-nakanishi/jekyll-dojo/tree/d2cf2ebb5a0cfe22864da7278bf38128a4b148b5

jekyll work in local but not work github.

The page build failed with the following error:

Your SCSS file css/main.scss has an error on line 36: File to import not found or unreadable: minima. For more information, see https://help.github.com/articles/page-build-failed-invalid-sass-or-scss.

Why work in local? How to work in github?