If you use less, you can import contextualize the css like this:
@import (inline) '../../bower_components/offline/themes/offline-theme-default.css';
.language-de {
@import (less) '../../bower_components/offline/themes/offline-language-german.css';
}
.language-en {
@import (less) '../../bower_components/offline/themes/offline-language-english.css';
}
You can then switch the language by setting the language-... class on your <body>
element for example.
UPDATE: If you use the cleancss tool, make sure that you add '@charset "UTF-8";' in your main LESS file... otherwise there will be an @charset inside a block and cleanncss will mess up your CSS.
UPDATE: SASS can import css as well. Like that:
@import '../../bower_components/offline/themes/offline-theme-default';
.language-de {
@import '../../bower_components/offline/themes/offline-language-german';
}
.language-en {
@import '../../bower_components/offline/themes/offline-language-english';
}