body {
    display: flex;
    flex-direction: column;
    align-items: center;
}

h1 {
    font-family: Arial, Helvetica, sans-serif;
    font-size: 1.5rem;
}
.calculator-container {
    width: 90%;
    max-width: 500px;
    background-color: black;
    color: white;
}
.calculator-display {
    text-align:left;
    background-color: black;
    color: white;
    font-family: 'Courier New', Courier, monospace;
    padding: 2rem;
    font-size: 1.5rem;
    flex-grow: 0;
}

.buttons-container {
    display: flex;
    flex-wrap: wrap;
    flex: 1;
}

button {
    flex: 1 1 calc(25% - 0.375rem);
    aspect-ratio: 1 / 1;
    font-size: 1.2rem;
    background-color: darkgray;
    color: white;
    border: none;
}

#add, #subtract, #multiply, #divide {
    background-color: orange;
    
}

footer {
    margin-top: 3.2rem;
}

a {
    text-decoration: none;
    text-decoration: underline;
    color: black
}