Why does (sqrt(2)/-2)^-4 = 4 ??

[ sqrt(2) / (-2) ] ^-4  =  [ (-2) / sqrt(2) ] ⁴  =  [ 2 / sqrt(2) ] ⁴  =  [ sqrt(2) ] ⁴  =  { [ sqrt(2) ] ² } ²  =  2²  =  4