Updated "About" page.
Fixed indentation in layout.
Moved <nav> into a <header>.
Made navigation align right.
Refactoring.
Added "logo".
Added tagline below title.
Demoted headline on contact page to <h2>.
Turned logo into a link.
Changed main text color into a dark gray.
Added footer to blog articles.
Moved article footer out of <article>.

This way it can get some distance from the main article.
Decreased <aside> font size a bit.
Moved tags a bit closer to header.
Changed font to Helvetica.
Slightly increased content width.
Added blog article about contact angle project.
Fixed: Links in contact angle article.