Plebejus idas - Idas Blue
I seem to miss out on this species a lot. I think it is more fidgety and alert than the very similar P. argus and I was unable to capture a really decent butterfly photograph until a visit to Northern Norway in 2018, where it is the only one of the two species to fly - see bottom of page.
Below are the butterfly images I managed to take in July 2018 in Finnmark, Northern Norway, where it flew in plenty around the coast.
Note that the brownish underside belongs to a female.