css - calc() in less doesn't work -

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• less aggressive compilation css3 calc 3 answers

i want div has right margin depending of screen width. wrote following css rule:

...{    right: calc(100% - 960px); } 

but see in following result in firebug:

right: calc(-860%) !important; 

how can fix it?

my problem using less instead of css. resolved doing

right: calc(~"100% - 960px");