Change the size of the rows

Is it possible to change the size of the rows?

Example from here
http://hurricane.darkbb.com/admin/css_tutorial.html

.row1
.row2
.row3

Hello.

It's not possible to put fixed sizes for rows, because this will also affect the other pages (inside sections, inside topics, on the portal, when you post a message).

For example here, look at the row1 where there's a slight gradient. You will see this same gradient on other pages. All the zones where you see the gradient correspond to the row1.