styles.css

*, *::before, *::after {
    box-sizing: border-box;
}

.calculator {
    width: 300px;
    margin: 100px auto;
    padding: 20px;
    border: 1px solid #ccc;
    box-shadow: 2px 2px 10px rgba(0, 0, 0, 0.1);
    background-color: #4d49b1;
}

.display {
    grid-column: span 3;
    width: 100%;
    font-size: 2em;
    text-align: right;
    padding: 10px;
    margin-bottom: 10px;
}

button {
    padding: 15px;
    font-size: 1.5em;
    margin: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
}

button:hover {
    background-color: #ddd;
}

.calculator {
    /* ... existing styles ... */
    display: grid;
    grid-template-columns: repeat(3, 1fr); /* 4 buttons in a row */
    gap: 6px; /* spacing between buttons */
}

body {
    font-family: 'Oswald', sans-serif;
}

button:nth-child(n+12):nth-child(-n+16) {
    background-color: #ff5252;
}