thank you very much

it's an idiom like in Ruslan translation, but as i saw on ngram not as pooular as the russian one?

is it not used in spoken russian?

it is used in spoken russian widely, I think what she means is that my variant is not that popular in english

"vanish into thin air" it s widely used in english ))

Oh, thanks. I just checked it out on here, compared to its literal translation.
https://books.google.com/ngrams/graph?content=vanish+into+thin+air%2Ccompletely+disappear&year_start=1800&year_end=2000&corpus=15&smoothing=3&share=&direct_url=t1%3B%2Cvanish%20into%20thin%20air%3B%2Cc0%3B.t1%3B%2Ccompletely%20disappear%3B%2Cc0
I might interprete the results wrongly. My bad. Dave, thanks for your clarification again!☺