Small puzzle for Shadowrun Returns [1+] (solution posted)

Ky4uKysgKystLi0gKy0uLi4gKy4rLS4gKysrKys=

original: K+KAouKAoisrICsrLeKAoi0gKy3igKLigKLigKIgK+KAoist4oCiICsrKysr

Game is Shadowrun Returns, level 1+, ends 22/01.
Three steps. If you need some help, check Zelgh's guide.
Hope everything's correct it wasn't. Have fun!

Hint 1: Second step is not found on Zelgh's guide.
Hint 2: Sequences in step 2 are all made of the same number of types in this particular case. But, generally speaking, they could be made of a variable (any) number of types, depending on what they represent.
Hint 3: Scales.

Edit 14/01: as TheRegalMachine pointed out, looks like encryption of a particular type only worked in the site I used and gave strange results on other sites. Therefore, I changed that character with a common one that will hopefully work with every site.

SOLUTION:
Step 1: this was easy, it was a simple base64 encryption (I used this tool). The decrypted message contained this line:
+..++ ++-.- +-... +.+-. +++++ or the original one: +••++ ++-•- +-••• +•+-• +++++
Step 2: there are only three different types in these strings: + , - and • ; this could suggest it's a ternary system. However, it isn't a normal base 3 system (0 1 2 10 11 12 20...), but it's a balanced ternary system (hint 3). It's a way to represent numbers using the powers of 3, similarly to the binary system where 0s and 1s represent the powers of 2. Every type stands for a power of 3 (starting from the rightmost 3^0 and raising the exponent at every type towards left), and the +, - and • (different notations can be used) indicate whether the respective power has positive, negative, or null value while summing all the numbers together. Some examples:
+- = 1x3^1 + (-1)x3^0 = 3 - 1 = 2
-+• = (-1)x3^2 + 1x3^1 + 0x3^0 = -9 + 3 + 0 = -6
+•-+ = 1x3^3 + 0x3^2 + (-1)x3^1 + 1x3^0 = 27 + 0 - 3 + 1 = 25
Now, our 5 strings: +••++ = 85, ++-•- = 98, +-••• = 54, +•+-• = 87, +++++ = 121. The fact that all strings each have 5 types is a coincidence (as stated in hint 2). 5 types are needed for numbers from 41 (+----) to 121 (+++++).
Step 3 (not really a step, but was needed to create step 2): very easy, these numbers represent ASCII characters and can be easily converted to a giveaway code using the same tool as before. 85 98 54 87 121 = Ub6Wy.

I know, it wasn't simple. Congratulations to solvers, thanks for trying to everybody else!
Have a nice week!