Latest Post Styled Different Than other Posts

Since you’re using the default loop (not a custom one), you can check the counter for the first (0th) loop and alter your output just for that one.

The WordPress support forum had a similar question that offered this bit of code:

if( $wp_query->current_post == 0 && !is_paged() ) { /*first post*/ }

You can put your whole block of HTML inside that if statement with your customization, or use it to just add classes to the elements for styling with CSS. For example, something like this could work:

$first_post = false;
if( $wp_query->current_post == 0 && !is_paged() ) { 
    $first_post = true;
}
// inside The Loop:
<div class="post excerpt <?php if( $first_post ) { echo 'first-post'; } ?>">

That would give you class="post excerpt first-post" on the first one and class="post excerpt " on the others. You can do this in addition to your other custom classes that are in your code.