However, I succeeded I edited the template's css file
../themes/classic/assets/css/theme.css
and added img in the tab-content> item
img {
display: block;
max-width: 100%;
height: auto;}
after modification, the code looks like this in this passage
tab-content>.active{display:block;}
img{
display: block;
max-width: 100%;
height: auto;}
.navbar{position:relative;padding:.5rem 1rem}
I checked the presta 1.7.6.1 version on standard template with the description window enlarged to the full window according to my description
https://www.presta-polskie-wsparcie.pl/strona/presta-1-7-szersze-pole-opisu-produktu
.png.022b5452a8f28f552bc9430097a16da2.png)