<main>
<div class="first-scheme">
<div class = "row">
<div class="col-sm-12">
<p>Hello World</p>
<button type="submit" formtarget="_blank" class="btn-sm">Read More</button>
</div>
</div>
</div>
i am trying to style the first-scheme using CSS
.first-scheme{
margin-top: 10px;
height: 250px;
width: 450px;
background:black;
color: white;
}
However, when I apply this CSS, there is no effect on the page