Giving style to "figcaption" images in articles.

[besocialbrand]

Hello everyone!
I am using the template Ja Teline V, and when I insert images into the articles the title text appears without design that is mixed between the text of the article.
That's why I need help adding design, but I can not find where to put the CSS code so it looks different.
Any ideas?
This is the CSS code I want to insert to modify the "figcaption" style:
figcaption {
background: #669837;
color:#ffffff;
border-color:#fff;
border-style: solid;
border-width:3px;
border-left-color: #41C0F0;
border-left-width:30px;
padding-left:5px;
padding-top:5px;
font-size:12px;
text-transform:uppercase ;
width:400px;
}

Attached image sample and css file where figcaption appears: "css-93e26-73372.zip".
http://cmcwecare.com/pdrrweb/index.php/ ... ta-en-casa

Thanks!

[Per Yngve Berg]

Doesn't the template have a separate css file for customisation?

[besocialbrand]

Files located in t3-assets/css
(jpg and ALLcss.zip)

CSS files.jpg

Thanks!

[besocialbrand]

Only file CSS attached!