body {
    margin: 0;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    background-color: beige;
}

.headding {
    text-align: center;
    font-size: 20px;
    margin-bottom: 30px;
}

.calculater {
    min-width: 300px;
    max-width: 400px;
    margin: auto;
    padding: 20px;
    border-radius: 20px;
    background-color: rgb(226, 238, 248);
    display: flex;
    flex-direction: column;
    box-shadow: rgba(0, 0, 0, 0.4) 0px 2px 4px, rgba(0, 0, 0, 0.3) 0px 7px 13px -3px, rgba(0, 0, 0, 0.2) 0px -3px 0px inset;
}

#display {
    display: flex;
}

#display input {
    margin: 10px;
    border-radius: 20px;
    outline: none;
    width: 100%;
    padding: 10px 20px;
    font-size: 24px;
    background-color: rgb(255, 255, 255);
}

#buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(4, 1fr);
    gap: 24px;
    margin: 10px auto;
}

#clear {
    background-color: black;
    color: white;
}

.operator {
    background-color: rgb(220, 19, 19);
    color: rgb(255, 255, 255);
}

#equal {
    background-color: rgb(6, 89, 145);
    color: white;
}

button {
    width: 50px;
    height: 50px;
    border-radius: 10px;
    font-size: 24px;
    font-weight: 900;
    background-color: white;
}

@media (min-width:425px) {

    .calculater {
        width: 400px;
    }

    button {
        width: 70px;
        height: 60px;
    }

}

@media (min-width:768px) {

    .calculater {
        width: 700px;
    }

    button {
        width: 80px;
        height: 80px;
    }

}