YA dystopian romance: the rich live in skyscrapers, the poor live on the ground. Main girl is from one of the richest families and falls for a lower class guy, they might run away? Read around 2014

[Reetta]

The book is very fast-paced and it's full of romance and action. The title is possibly just one word. The main guy's name was pretty short and I remember this being a part of a series (a trilogy?). The cover was dark green but it was a translation so it might be a different color in the English edition.

[Stacy]

The Thousandth floor by Katharine McGee, I think this is the book you have described.

[Ingo]

For the click:
The Thousandth Floor

[Rainbowheart]

Mystic City?

[Kris]

Reetta left the group. Moving to the "Query abandoned by poster" folder

[Rainbowheart]

Aww. :(