body{
    background-color: #f4f4f9;
    font-family: Arial, Helvetica, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}

.calculator{
    width: 320px;
    background-color: #333;
    border-radius: 15px;
    padding: 20px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2); 
}

#result{
   width : 100%;
   padding: 20px;
   font-size: 2rem;
   border: none;
   outline: none;
   text-align: right;
   margin-bottom: 20px;
   border-radius: 10px;
   background-color: #f9f9f9;
   box-shadow: inset 0 3px 5px rgba(0, 0, 0, 0.1);
   
}
.btn-container{
    margin-left: 15px;
}
button{
    width: 70px;
    height: 70px;
    font-size: 1.5rem;
    margin: 10px;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    transition: background-color 0.3s ease;
    color: white;
}
button.operator{
    background-color: #ff8c00;
}
button.number{
    background-color: #4caf50;
}
button.clear, button.delete{
    background-color: #f44336;
}
button.equal{
    background-color: #008cff;
}
button:hover{
    background-color: #666;
}