#display{
    padding: 20px;
    width: 90%;
    border-radius:20px ;
    background-color: black; 
    color: white;
    font-size: xx-large;
    font-weight: bolder

}
button{
    width: 100px;
    height: 100px;
    border-radius: 50px;
    border: none;
    background-color: gray;
    color: white;
    font-weight: bold;
    cursor: pointer;
    font-size: xx-large;
}
#keys{
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    padding: 25px;
    
}
.calculator{
    background-color: black;
    border-radius: 15px;
   
}
body{
    margin: 0%;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
   
}
button:hover{
    background-color: rgb(97, 90, 90);
}
button:active{
    background-color: lightblue;
}
.operator-btn{
    background-color: rgb(255, 136, 0);
    
}
.operator-btn:hover{
    background-color: rgb(255, 208, 0);
}
.operator-btn:active{
    background-color: lightcoral;

}