CSS

<div class="footer">
    <div class="footer-content">
        <div class="footer-section about">
            <h2>Jewelry Store</h2>
            <p>
                At Melissa's Store, we offer the finest jewelry. Our pieces are designed to capture the essence of beauty, elegance, and sophistication.
            </p>
        </div>
        <div class="footer-section links">
            <h2>Quick Links</h2>
            <ul>
                <li><a href="index.html">Home</a></li>
                <li><a href="products.html">Products</a></li>
                <li><a href="about.html">About Us</a></li>
                <li><a href="contact.html">Contact</a></li>
            </ul>
        </div>
        <div class="footer-section contact">
            <h2>Contact Us</h2>
            <p><i class="fas "></i> Scarborough Ontario</p>
            <p><i class="fas"></i> +1 234 567 890</p>
            <p><i class="fas"></i> contact@contact.com</p>
        </div>
    </div>
    <div class="footer-bottom">
        &copy; 2023 Melissa's Store | Designed by Mathew
    </div>
</div>
```

This is the part of the index page in question: 
```
  <div class="products">
                <!-- Example product items. In a real-world scenario, these would be dynamically loaded. -->
                <div class="product">
                    <img src="images/image1.jpeg" alt="Jewelry Item 1" width="100%">
                    <button class="add-to-cart-btn">Add to Cart</button>
                </div>
            
                <div class="product">
                    <img src="images/image2.jpeg" alt="Jewelry Item 2" width="100%">
                    <button class="add-to-cart-btn">Add to Cart</button>
                </div>
            
                <div class="product">
                    <img src="images/image2.jpeg" alt="Jewelry Item 2" width="100%">
                    <button class="add-to-cart-btn">Add to Cart</button>
                </div>
            
                <div class="product">
                    <img src="images/image1.jpeg" alt="Jewelry Item 2" width="100%">
                    <button class="add-to-cart-btn">Add to Cart</button>
                </div>
                
                <!-- Add more product items as needed -->
            </div>
        </div>
        <div id="footerContainer"></div>

        <script>
            fetch('footer.html')
                .then(response => response.text())
                .then(data => {
                    document.getElementById('footerContainer').innerHTML = data;
                });
        </script>
    </div>
```

This is my CSS:
```
body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    padding-top: 5%;
    
}


.header {
    background-color: #333;
    color: #fff;
    padding: 20px 0;
    text-align: center;
    position: fixed;     /* This will fix the header at the top */
    top: 0;              /* Ensure it's at the very top */
    left: 0;             /* Align it to the left edge */
    right: 0;            /* Align it to the right edge */
    z-index: 1000;       /* Ensure it stays on top of other elements */
}

.cart {
    position: absolute;
    top: 20px;
    right: 10px;
}

.products {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    max-height: 600px; /* Change this value based on your needs */
    padding: 10px;
}

.product {
    /* border: 1px solid #ccc; */
    margin: 10px;
    padding: 10px;
    width: calc(33% - 20px); /* width minus margin */
    text-align: center;
    position: relative;
    overflow: hidden; 
}
@media only screen and (max-width: 768px) {  /* This threshold (768px) is just an example. Adjust as needed */
    
    .product {
        width: calc(100% - 20px);  /* Occupies full width minus margin */
        flex: 1 0 auto;
    }

    .footer{
        flex-shrink: 0;
    }
    body, html {
        height: 100%;
        margin: 0;
        padding-top: 5%;
    }
    .main-wrapper {
        display: grid;
        grid-template-rows: auto 1fr auto;
    }
    
    .site-content {
        width: 95%;
        overflow: hidden;  /* Allows the content to scroll if it overflows */
    }
}

.add-to-cart-btn {
    position: absolute;
    bottom: 10px;      /* Adjust as needed for vertical position */
    right: 10px;       /* Adjust as needed for horizontal position */
    background-color: #333;  /* Any color you want */
    color: #fff;      /* Font color */
    border: none;
    padding: 5px 15px;
    cursor: pointer;
    transition: background-color 0.3s ease;

    /* Add any other styles you want for the button */
}

.add-to-cart-btn:hover {
    background-color: #555;  /* Adjust hover color as needed */
}

.footer {
    background-color: #333;
    color: #ffffff;
    padding: 20px 0;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    padding: 0 20px;
    max-width: 1200px;
    margin: 0 auto;
}

.footer-section {
    flex: 1;
    padding: 0 20px;
}

.footer-bottom {
    text-align: center;
    padding: 10px;
    background-color: #222;
}

ul {
    list-style: none;
    padding: 0;
}

li {
    margin-bottom: 10px;
}

a {
    color: #ffffff;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

/* If you're using Font Awesome for icons */
.fas {
    margin-right: 10px;
}

.button-16 {
  background-color: #f8f9fa;
  border: 1px solid #f8f9fa;
  border-radius: 4px;
  color: #3c4043;
  cursor: pointer;
  font-family: arial,sans-serif;

}

.button-16:hover {
  border-color: #dadce0;
  box-shadow: rgba(0, 0, 0, .1) 0 1px 1px;
  color: #202124;
}

.button-16:focus {
  border-color: #4285f4;
  outline: none;
}