QR code component

Hi, nice work, i like your project but i have a few suggestions

1. Semantic HTML Elements: Consider using more semantic HTML elements to improve accessibility and SEO. For example, <main> could be used to wrap the main content area instead of <div class="card">.

2. Class Naming: Ensure consistent and meaningful class names. For instance, card_item1 and card_item2 could be more descriptive, such as qr-code-container and content-container.

3. Footer Attribution: Ensure the footer attribution is easily readable and accessible. Consider increasing the font size (font-size: 11px; may be too small for some users).

Great job. Maybe you should separate the CSS from the HTML by creating a new file