Introduce "Custom styles / Templates" section in core cards for much easier change of CSS/styling of cards (like bubble card)

[nagtegaal]

Introduce a "Styles" section in all the default available core cards to lower the bar for customizations and easier editing of CSS.
A magnificent example could be found in the amazing bubble-card.

This will eliminate the need for the excellent, but hard to grasp card_mod which is so widely used to style front-end in-card and card elements differently.

[stefaanv]

Strong support for this request.
Many time you want to tweak a card just a little bit to f.i. increase text size, decrease overall size, etc
The only option I know of is card_mod but that can be really hard w.r.t. shadow DOM.
Also card_mod is a "fix" for something that should be a feature instead of some to be fixed