Edit in JSFiddle

body {
  background: #0C2939;
  font-size: 80%;
}

main {
  background: white;
  margin: 20px 0;
  padding: 50px;
}

main a {
  background: black;
  color: white;
  padding: 40px 30px;
  text-decoration: none;
}

<main>
  <a href="#0">Somos</a>
  <a href="#0">texto</a>
  <a href="#0">no</a>
  <a href="#0">centro</a>
</main>