body{
    background-color: #4CAF50;
}

#cal{
  width: 300px;
  margin: 0 auto;
}

button{
    border-radius: 8px;
     transition-duration: 0.4s;
     background-color: white;
    border-color: #f44336;
}

button:hover{
    
     transition-duration: 0.4s;
     background-color: #f44336;
    color: white;
    
}

#res{
    
    background: #cfd6d0;
    border-radius: 15px;
}

input:focus {
  background-color: lightblue;
}