body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

header {
    background-color: #333;
    color: white;
    text-align: center;
    padding: 1rem;
}

main {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-around;
    padding: 1rem;
    flex-grow: 1;
}

section {
    background-color: #f0f0f0;
    border-radius: 8px;
    padding: 1rem;
    margin-bottom: 1rem;
    width: 100%;
    max-width: 500px;
}

h2 {
    margin-top: 0;
}

#calc-display {
    background-color: white;
    border: 1px solid #ddd;
    padding: 0.5rem;
    margin-bottom: 0.5rem;
    text-align: right;
    font-size: 1.5rem;
}

#calc-buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0.5rem;
}

button {
    padding: 0.5rem;
    font-size: 1.2rem;
    border: none;
    background-color: #4CAF50;
    color: white;
    cursor: pointer;
}

button:hover {
    background-color: #45a049;
}

#products {
    list-style-type: none;
    padding: 0;
}

.product-item {
    background-color: white;
    border: 1px solid #ddd;
    margin-bottom: 0.5rem;
    padding: 0.5rem;
    display: flex;
    align-items: center;
}

.product-image {
    width: 50px;
    height: 50px;
    object-fit: cover;
    margin-right: 0.5rem;
}

@media (max-width: 600px) {
    main {
        flex-direction: column;
    }
}