*{
  margin:0;
  padding:0;
}
body{
  height: 100vh;
  width:100vw;
  display: flex;
  align-items:center;
  justify-content:center;
  background-color:white;
  transition: all 1.3s ease-in-out;
}
#btn-mode{
  background-color:gray;
  width: 10rem;
  height: 3rem;
  padding:0.2rem 0.5rem 0.2rem 0.5rem;
  font-weight: 600;
  border:1px solid black;
  border-radius: 8px;
  font-size: larger;
  box-shadow: 0px 4px 10px black;
  transition: all 1s ease-in-out;
}
#btn-mode:hover{
  background-color: deepskyblue;
  cursor:pointer;
}