.demo {
  padding: 20px;
  width:200px;
  margin:0 auto;
}

.button {
  color: white;
  display: inline-block;
  font-size: 16px;
  width: 100%;
  border-radius: 20px;
  text-align:center;
  cursor: pointer;
  transition: all 0.5s;
}

.button:hover {
  background-color: white;
}

.blue {
  background-color: blue;
  border: 2px solid blue;
}

.blue:hover {
  color: blue;
  border: 2px solid blue;
}

.red {
  background-color: red;
  border: 2px solid red;
}

.red:hover {
  color: red;
  border: 2px solid red;
}