body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    font-family: cursive;
}

.calculator {
    width: 320px;
    background-color: rgb(128, 128, 128);
    padding: 20px;
    border-radius: 20px;
    box-shadow: 10px 10px 20px black, -10px -10px 20px white;
}

.display {
    background-color: white;
    text-align: right;
    font-size: 20px;
    padding: 16px;
    border-radius: 15px;
    box-shadow: inset 4px 4px 8px black, inset -4px -4px 8px white;
    margin: 10px;
}

.buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px
}

.btn {
    border: none;
    font-size: 16px;
    background-color: white;
    padding: 16px;
    border-radius: 10px;
    cursor: pointer;
    box-shadow: 4px 4px 6px black, -4px -4px 6px rgb(123, 122, 122);
}

.btn:active {
    box-shadow: inset 4px 4px 6px black, inset -4px -4px 6px white;
}

.clear {
    grid-column: span 4;
    background-color: rgb(249, 65, 65);
    color: white
}

h1 {
    text-align: center;
    color: white;
}