body {
  width: 80%;
  background-color: grey
}

.hoofd {
  background-color: blue;
  border: 2px solid black;
  width: 1
    00%;
  border-width: 10px;
  border-block-color: black;
  float;
  text-align: center;
}

.all {
  background-color: lightgray;
  float;
  align-self;
  padding: 10px;
}