.content {
  width: 900px;
  margin: auto;
}

.snake {
  width: 200px;
  height: 200px;
  padding: 0;
  border: 5px solid black;
  margin: auto;
  position: relative;
}

.segment {
  width: 10px;
  height: 10px;
  position: absolute;
  background: black;
}

.apple {
  width: 10px;
  height: 10px;
  position: absolute;
  background: green;
}