Logo full screen but with max size. How to do?

Hi and thank you for this wonder plugin!
Hope you are well!

I set the image as background and discovered if the image is big is not showed fully on mobile so I use to check the option to show the image full screen size but on mobile now is OK and on Desktop the image is too big.

So in the settings Include an ad, or your own block of code I put:

<style>
html div.lp-screen
 {
	background-size: 30% !important;
}
</style>

This seems work well but when the loading reach the 100% the background image is again resized to full screen.

What CSS I need to add to keep background-size: 30% !important; also when 100% is reached?

Hope to get a kind reply, thank you again!

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