* {
  box-sizing: border-box;
}

.week-04 main {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}

.week-04 .dream {
  width: 100px;
  height: 50px;
  background-color: lime;
  position: absolute; 
  border-radius: 100%;
}
.week-04 .dream:hover {
  background-color: crimson;
}

.week-04 #dream-01 {
  top: 10%;
}
.week-04 #dream-02 {
  top: 20%;
}
.week-04 #dream-03 {
  top: 30%;
}