<main>
  <h2>Content</h2>
</main>
<footer>
  <div class="item-1">
    <p>Some thing</p>
    <p>Some thing</p>
    <p>Some thing</p>
  </div>
  <div class="item-2">
    <p>Some thing</p>
    <p>Some thing</p>
    <p>Some thing</p>
  </div>
  <div class="item-3">
    <p>Some thing</p>
    <p>Some thing</p>
    <p>Some thing</p>
  </div>
  <div class="item-4">
    <p>Some thing</p>
    <p>Some thing</p>
    <p>Some thing</p>
  </div>
</footer>

body {
  overflow-x: hidden;
  margin: 0;
  padding: 0;
}
main {
  width: 100%;
  height: 100vh;
  background: #535353;
  display: flex;
  justify-content: center;
  align-items: center;
}
h2 {
  color: yellow;
  font-size: 50px;
  text-transform: uppercase;
  
}
footer {
  width: 100%;
  max-width: 100%;
  height: auto;
  background: #333;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  padding: 20px;
  box-sizing: border-box;
}
footer div {
  height: 200px;
  width: 200px;
  color: #fff;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  margin-bottom: 20px;
}
.item-1 {
  background: #000;
}
.item-2 {
  background: #222;
}
.item-3 {
  background: #444;
}
.item-4 {
  background: #555;
}
@media screen and (max-width: 640px) {
  footer {
    flex-wrap: wrap;
    justify-content: center;
  }
  footer div:nth-child(2n) {
    margin-left: 20px;
  }
}