You can make an HTML file self-contained by embedding CSS in a `<style>` tag and converting images to Base64, embedding them directly in the `<img>` tag as data

You can make an HTML file self-contained by embedding CSS in a `<style>` tag and converting images to Base64, embedding them directly in the `<img>` tag as data URLs. This removes the need for external files, making everything contained within a single HTML file.