html,
body {
  margin: 0;
  padding: 0;
}

.parent1 {
  display: flex;
  justify-content: space-between;
}

.child1 {
  width: 100px;
  height: 100px;
  color: white;
  background-color: black;
}

.sub-parent {
  display: flex;
}

.child1-move {
  position: relative;
  right: 5px;
}

.line {
  border-bottom: 1px solid gray;
  width: 100%;
}

.parent2 {
  display: flex;
  flex-direction: column;
}

.child1-center {
  align-self: center;
}

.child1-end {
  align-self: flex-end;
}

.parent3 {
  display: flex;
  justify-content: center;
  margin-top: 20px;
}

.child1-big {
  width: 200px;
  height: 200px;
  color: white;
  background-color: gray;
  position: relative; /* 이게 상위에 있어야 absolute가 상위 기준!*/
}

.child1-position {
  position: absolute;
  left: 50px;
  top: 50px;
}

.child2 {
  background-color: gray;
}

.child2-move {
  position: relative;
  left: 50px;
  top: -50px;
}

.parent4 {
  height: 50vh;
  display: flex;
  justify-content: flex-end;
  align-items: flex-end;
}

.child1-big2 {
  width: 400px;
  height: 200px;
  color: white;
  background-color: gray;
  position: relative; /* 이게 상위에 있어야 absolute가 상위 기준!*/
}

.child1-top {
  position: absolute;
  top: 0;
  right: 0;
}

.child1-bottom {
  position: absolute;
  bottom: 0;
  left: 0;
}