What to do if scripts on android slow down?

Question

css

Good afternoon. There is a page .
On a computer, on smartphones with Windows Mobile - everything is fine. iOS has not been tested yet. But on Andoroid, when you open the menu, for example, you can see that the script does not work smoothly. There is no such ease as on a PC, for example. Where to dig, tell me, please. The smartphone is not weak, on which it lags.