条件・譲歩N2
〜限り（は）、〜限りでは
as long as... / as far as...
Structure
V-辞書形／ている形 + 限り（は）；V-た形 + 限りでは
Explanation
〜限り(は) means "as long as a certain state continues", often with 〜ない限り or 〜ている限り. 〜限りでは means "as far as (what one has seen, heard, investigated) is concerned", attached to the ta-form of verbs like 見る/聞く/調べる or 知っている; the main clause is the speaker's judgment.
Examples
体が丈夫な限りは、働き続けたいと思っています。
As long as I'm healthy, I want to keep working.
私が知っている限りでは、彼は今も独身です。
As far as I know, he's still single.
Note
〜ない限り ("as long as... not") is a common combination; after 〜限りでは the main clause often uses speculation like 〜ようだ or 〜らしい.