Je pose cela là pour de futurs partages

and the code example: https://codesandbox.io/s/css-grid-blog-bonus-v2-nn7t2

because it is faster than a static website... because everything is in the RAM.

Why not :)

#idea #project fork it to provide a demo

Headings are not focusable because they are not interactive, as long as the headings are not links… ;)

Here an example of how to make focused element transition on focus:

section:focus {
  outline: 0;
  animation: yellowFade 3s forwards;
}
@keyframes yellowFade {
  from { background: lightYellow; }
  to   { background: white; }
}