一旦保存较少的文件，如何让less2css编译所有文件？

I have style.less which import "page.less". When something is changed in page.less, I have to turn to file style.less and save to let less2css compile so that the changes will take effect otherwise it doesn't because page.less is imported! So is there a way to let less2css compile all files when one of them is changed? I have style.less which import "page.less". Whe