How can I translate product page buttons and texts for multiple languages?

Hello all,

the buttons and texts on my product page are provided via an app, as it is a product configurator. The buy and shopping cart buttons as well.

The only problem is that I can not have these translated accordingly I Shopify for multiple languages. The app also has no function.

Now I am trying with my own code to translate these for one language. For the “Buy” and “Shopping Cart” button I have also managed so far with the following code:

//Buy now translation
html:lang(de) .tee-btn--buynow span {
  display: none;
}

html:lang(de) .tee-btn--buynow:after {
  content: "Jetzt kaufen";
}
//ATC translation
html:lang(de) .tee-btn--atc span {
  display: none;
}

html:lang(de) .tee-btn--atc:after {
  content: "Zum Warenkorb";
}
//Preview translation
html:lang(de) .tee-btn--preview span {
  display: none;
}

html:lang(de) .tee-btn--preview:after {
  content: "Vorschau";
}

However, with the same code I can’t get it to work for the other elements, which I don’t understand. E.G. the text in the Preview Button does not hide:

I also want to translate the following blocks, but i cannot find the correct blocks in the code:

Can someone help me please.

Would be grateful for any tip.

Greetings