body{
    margin: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100vh;
}
#calculater{
    background-color: rgb(122, 122, 122);
    max-width: 450px;
    overflow: hidden;
    border-radius: 20px;  
    border-style: solid;
}
#display{
    
    width: 400px;
    height: 70px;
    background-color: rgb(170, 170, 170);
    text-align: left;
    font-size: 40px;
    color: aliceblue;
    border-radius: 20px;
}
#key{
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    padding: 20px;
}
button{
    height: 80px;
    width: 80px;
    border: none;
    border-radius: 20px;
    background-color: rgb(48, 48, 48);
    color: aliceblue;
    font-size: 30px;
    cursor: pointer;
    font-weight:bold;
}
button:hover{
    background-color: rgb(81, 81, 81);
}
button:active{
    background-color: rgb(157, 157, 157);
}
.operator{
    background-color: orangered;
}
.operator:hover{
    background-color: rgb(150, 150, 150);
}
.operator:active{
    background-color: rgb(172, 172, 172);
}