You can style the way focusable elements look if you want to customize default accessibility styles in browsers. While you should be very cautious not to create any accessibility issues, you can safely modify the visual "focus ring" on focused elements to give it a bit more clarity and panache.
Link and button spacing on touch screens is an accessibility issue. If we place links too close together some users may find it difficult to tap the right thing. I noticed the links in the footer on this site were very close on my phone, so here are some of the considerations I had and the solution I came up with to fix this.
This is a conversational how-to guide for building this website. It is far from comprehensive and it assumes this is not your first encounter with a lot of these concepts. Feel free to disagree with any of this — my opinions may not overlap with yours!