<div class="container-area">
  <button>Upload</button>
</div>

$gray: #efefef;
$dark: #332200;
$white: #ffffff;
$green: #009688;

.container-area {
  width: 50rem;
  height: 20rem;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 0.4rem solid $dark;
  background-color: $gray;
  background-image: linear-gradient($white .4rem, transparent .4rem), linear-gradient(90deg, $white .4rem, transparent .4rem);
  background-size: 10rem 10rem;
  background-position: -0.1rem -0.1rem;
  
  button {
    background: $green;
    color: $white;
    border: none;
    padding: 0.5rem 1.5rem;
    text-transform: uppercase;
    font-weight: bold;
  }
}