Firstly, left padding on this card is managed via an inbuilt setting. See the documentation for details on the padding: key.
Secondly, it looks like you are trying to apply changes via the custom frontend component card-mod: do you actually have it installed? And which version? Since version 3.4.0, all styles need to be under an explicit card_mod key.
If wanting to remove the display of icons from entities for example, then you are probably better off asking this in the dedicated thread for card-mod, where you find detailed explanations and examples, especially in this excellent post by community member Ildar_Gabdullin.