*{
    padding: 0;
    margin: 0;
    box-sizing: border-box;
    font-family: 'Times New Roman', Times, serif
}
body{
    height: 100vh;
    background:linear-gradient(to bottom,red 50%,black 50%);
}
.calculator{
    width: 400px;
    background-color: darkblue;
    padding: 50px 30px;
    position: absolute;
    transform: translate(-50%,-50%);
    top: 50%;
    left: 50%;
    border-radius: 8px; 
    box-shadow: 0 20px 50px, black;
}
.display{
    width: 100%;
}
.display input{
    width: 100%;
    padding: 15px 10px;
    text-align: right;
    border: none;
    background-color: transparent;
    color: white;
    font-size: 35px;
}
.display input::placeholder{
    display: grid;
    grid-template-columns: repeat(4,1fr);
    grid-gap: 20px;
    margin-top: 40px;
}
.button{
    justify-items: center;
}
.button input[type="button"]{
    font-size: 20px;
    padding:20px;
    border: none;
    background-color: transparent;
    color: white;
    cursor: pointer;
    border-radius: 5px;
    align-items: center;
}
.button input[type="button"]:hover{
    grid-row: span 2;
    background-color: red;
}
.button input[type="button"][value="0"]{
    grid-column: span 2;
}