the same as mine

[ratóncolorao]

Hello,

Could you, please, correct my mistakes?

You always wear the same design as hers when you go to a party.

Thanks

 

[emsr2d2]

What do you mean by "design"? Do you mean "dress/outfit"?

You always wear the same dress/outfit as she does when you go to a party.
You two always wear the same dress/outfit when you go to a party.

Turning up in the same dress/outfit as another woman is, I'm told, something which terrifies many women.

 

[Raymott]

You always wear the same design as hers when you go to a party.

I would not call that wrong, but the above option is better.
If we can say "Her dress is the same as mine", we can say "My dress is the same as hers". However, in the context provided, it's "her dress", but arguably not "her design".