Center a section in Divi

Hello All,

I am currently creating a website for which I want to create an area which would be center in the page, without scrolling.

To give you an example, it should look like on the attached file. The square in which the webiste is contained is in fact around 80% height and weight, fixed in the center of the screen. Then the logo and the menu is on the bottom of that square and the content above, in the square.

In order to center this square, I tried to use the flex css code:

.ds-vertical-align {
display: flex;
flex-direction: column;
justify-content: center;
display: -webkit-box;
display: -webkit-flex;
display: -moz-box;
display: -ms-flexbox;
-webkit-box-orient: vertical;
-webkit-box-direction: normal;
-webkit-flex-direction: column;
-moz-box-orient: vertical;
-moz-box-direction: normal;
-ms-flex-direction: column;
-webkit-box-pack: center;
-webkit-justify-content: center;
-moz-box-pack: center;
-ms-flex-pack: center;
}

But it seems to be working only for lines with columns, not for sections.

My question is therefore, is there any solution to center a section in divi ?

Thank you in advance for your kind assistance,