style.css

*{
    margin: 0;
    padding: 0;
}

.container{
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    height:100vh;
    background-color: #a3b18a;
}
.calculator{
    
    background: #05D1A9;
    background: linear-gradient(315deg, #d4a373, #e9edc9);
    padding: 20px;
    border-radius: 20px;
}
.calculator form input{
    border: 0;
    outline: 0;
    background-color: transparent; 
    box-shadow: -1px 2px 5px 1px #588157;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    margin: 10px;
    font-size: 20px;
    cursor: pointer;
}

form .display{
    display: flex;
    justify-content: flex-end;
}
form .display input{
    width: 300px;
    height: 90px;
    border: 0;
    outline: 0;
    text-align: right;
    font-size: 25px;
    padding: 8px;
    box-shadow: none;
    margin-top: 0;
}