How to add a border to a text module

Hello, I’ve been trying for hours to figure out how to add a rounded border around an image and some text on our Divi theme WordPress site. I’ve used the Page Builder Editor to create 3 columns, each with unique text.

I know these are the values I want for the border:

border:2px solid #08810f;
padding:10px 40px;
width:300px;
border-radius:25px;

Here was my attempt to create the border:

<div style="
{border:2px solid #08810f;
padding:10px 40px;
width:300px;
border-radius:25px;">
}
<h3><a href="https://www.perlustro.biz/wp-content/uploads/New-website_small.jpg"><img class="alignnone size-full wp-image-1638" src="https://www.perlustro.biz/wp-content/uploads/New-website_small.jpg" alt="New website_small" width="187" height="93" /></a></h3>
<h3>Perlustro relaunches website</h3>
Perlustro, L.P., makers of iLOOKIX and iSEEK computer forensics software, has relaunched its website, Perlustro.com.
. . .
</div>

What am I doing wrong? (Here’s the page in question: https://www.perlustro.biz/newsroom )