The ART theme is set with the English default. But it is easy to translate into another language.
There are two main POT files ready:
You could translate the PO/MO file by Loco Translate WP plugin. Refer to the video tutorials on how to translate from the POT file.
There are the 6 translated(the strings in frontend pages) PO files including German, France, Spanish, Japanese, Chinese, Finnish. If your language is one of them. The PO files would be linked by default. You could edit the PO file. Please check the video tutorials:
You could also check more doc about the Loco Translate(check the DOC).
Tips: If it doesn’t work for some strings, please make the boxes empty in “Art Theme > Theme Options > General Settings: Descriptions”.