#c1 {
  display: block;
  width: 600px;
  height: 400px;
  border: 2px solid red;
  margin: 20px;
}

#b1 {
  cursor: pointer;
  font-size: 16px;
  border: 2px solid red;
  background-color: #fff;
  width: 130px;
  height: 30px;
  margin-left: 20px;
}