HTML
- Try to add meta tag with description to improve your SEO.
- You can change the <div> (class="card-profile") to an <article> tag.
- Use alt text more descriptive: instead of "photo avatar" try for example "picture of user Jessica Randall".
- In this project you have a list of social media. I would suggest using the <ul> and <li> tags.
CSS
- I wouldn't use font-size: 62.5%. Here's a link explaining why not: font-size: 62.5%.
- In transition (.btn): Be more specific, use "color" instead of "all".
Other
- Amazing Read.me file!