Background of custom card for my wifi qr code

Hi,
can anybody help me to get off the grey background around my qr code für my guest wifi?

What happens if you remove (comment) the ‘50%’ config entries?

the qr code isn´t there anymore…they are for the position

Do you have the card mod installed?

Try:

    card_mod:
      style: |
        ha-card {
          border-radius: 18px;
          background: none;
          box-shadow: none;
          border: none;
        }

BTW, why not using a Picture entity card instead of Picture elements?

type: picture-entity
entity: ....
show_state: false
show_name: false

did not work

but picture-entity works
how can i set the size?

What is a point of asking about a particular solution NOT a person who proposed this solution? You do not need to resize a card in case of picture-entity card.