리버's 아름다운 소풍

These divs have the following CSS properties:

#div1 {
  width: 300px;
  height: 100px;
  border: 2px solid #f00;
}
#div2 {
  width: 300px;
  height: 100px;
  border: 2px solid #00f;
}

#div1 {
  width: 300px;
  height: 100px;
  margin-bottom: 30px;
  border: 2px solid #f00;
}
#div2 {
  width: 300px;
  height: 100px;
  border: 2px solid #00f;
}

#div1 {
  width: 300px;
  height: 100px;
  margin-bottom: -30px;
  border: 2px solid #f00;
}
#div2 {
  width: 300px;
  height: 100px;
  border: 2px solid #00f;
}


PS) 박스모델 오류도 자꾸 잊게 된다. 상기하는 차원에서..

div {
width: 100px;
padding: 10px;
border: 5px solid black;
margin: 10px; }