F-35 wings are most definitely swept and stealth shaping has moved on a very long way since the F-117.
Got to say I can find no definition of swept wing which matches the shape of the F-35 wing, probably because it isn't swept.
Take a look at the F 104 wing; it has a very similar planform and only precedes the F35 by about 50 years.
As for curves I recall reading somewhere that HS Hawks had a remarkably low RCS from certain angles, this was attributed to the shape of the fuselage, but jimjim is right, the computer has made it possible to design and test much more readily. The B-2 is an excellent example of this and precedes the F-35 by about 10 years