Show one announcement full width on default theme home screen?

Is it possible to use a Journal Style Sheet to make the announcements section of the home screen show only one announcement full width?

Right now it looks like there are two text blocks. One shows the most recent announcement, the other is just empty space. I managed to find a tip that removed the divider between the two, but can’t figure out how to remove the empty block and give the space to the other one.

Here’s the css to remove the divider if that helps.

.pkp_page_index .cmp_announcements > .obj_announcement_summary:before,
.pkp_page_index .cmp_announcements > .more:before {
border: none;
}

Here’s the site: The Graduate History Review

I’m using the default theme on Open Journal Systems 3.1.1.4.

Clearly I’m new to this - thanks for your patience!

update: have working solution, not sure if it’s breaking something else or not but the appearance is what I want

added the following to Journal Style Sheet

/* make announcement block on main page wider than default of 65% */
.pkp_page_index .cmp_announcements > .obj_announcement_summary {
width: 90%
}