As you may have noticed, moving and selecting buildings in the WebGL version of the game works differently than in the previous Flash version of the Trainstation game.
In order to be able to manipulate with the buildings and decorations at your station you will now have to enter the building mode first. You can access it after clicking on the Edit Station button right here:

Once in the building mode, you have to use these buttons in order to select the street on which you desire to make the changes, sell buildings, etc.

You can even align your buildings at the selected station to either left or right. This feature was available in the App version of the game already so some of you are familiar with it. Those of you who are not, you can use this feature after clicking on one of these buttons:
