.box {
  position: absolute;
  width: 100px;
  height: 100px;
  background-color: blue;
}
.wrapper {
  position: relative;
  width: 400px;
  height: 400px;
  border: 3px solid red;
}
button {
  margin-bottom: 10px;
  margin-top: 10px;
  width: 100px;
  height: 40px;
  background-color: yellow;
  border: none;
}