body {
    display: flex;
    flex-direction: column;
    align-items: center;
    font-family: 'Roboto', sans-serif;
}

h1 {
    padding: 20px;
}

button {
    font-family: 'Roboto', sans-serif;
    font-size: x-large;
    border-radius: 5px;
    border-color: black;
    background-color: hsl(214, 100%, 78%);
}

button:hover {
    background-color: hsl(214, 100%, 57%);
}

.number-button {
    background-color: hsl(32, 100%, 69%);
}

.number-button:hover {
    background-color: hsl(32, 100%, 49%);
}

#calculator {
    display: grid;
    box-sizing: border-box;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: 1.5fr 0.9fr 0.9fr 0.9fr 0.9fr 0.9fr;        
    min-width: 500px;
    max-width: 500px;
    min-height: 600px;
    max-height: 600px;
    background-color: black;
    border: 2px solid black;
    gap: 8px;
    margin-top: 80px;
    padding: 15px;
    border-radius: 2%;
}

#input {
    grid-column: span 4;
    display: flex;
    flex-direction: column-reverse;
    align-items: flex-end;
    font-size: 90px;
    font-family: 'Roboto', sans-serif;
    background-color: whitesmoke;
    border: 2px solid black;
    border-radius: 5px;
    padding-left: 10px;
    padding-right: 5px;
}

#zero {
    grid-column: span 2;
}

.footer {
    display: flex;
    align-items: center;
    justify-content: center;
    padding-top: 30px;
}