Adjacent selector

<h1 class="entry-title">My Title</h1>
<div class="testimonial-data">
<p class="testimonial-content">My paragraph text</p>
</div>

<style>
p {
   margin: 10px 0;
}
h1.entry-title + p.testimonial-cotent {
   margin-top: 0;
}
</style>