less import at-rules reference vs inline vs less vs css vs once vs multiple vs optional
/*
* All of less at-rules as of latest version from todays date.
*/
/* Reference: Use to import external files, but without adding the imported styles to the compiled output unless referenced.*/
@import (reference) "foo.less";
/* Inline: Use to include external files, but not process them. */
@import (inline) "not-less-compatible.css";
/* Less: Use to treat imported files as Less, regardless of file extension. */
@import (less) "foo.css";
/* Css: Use to treat imported files as regular CSS, regardless of file extension. This means the import statement will be left as it is. */
@import (css) "foo.less";
/* [DEFAULT] Once: The default behavior of @import statements. It means the file is imported only once and subsequent import statements for that file will be ignored. */
@import (once) "foo.less";
/* Multiple: Use to allow importing of multiple files with the same name. This is the opposite behavior to once. */
@import (multiple) "foo.less";
@import (multiple) "foo.less";
/* Optional: Use to allow importing of a file only when it exists. Without the optional keyword Less throws a FileError and stops compiling when importing a file that can not be found. */
@import (optional) "foo.less";