CSS's line-height can make the links' line boxes overlap vertically. SpatNav needs to handle these overlapping focusables.

This test looks a bit artificial because the Ahem font's "glyphs" are squares that fill the entire line height. Real-life fonts don't; they have varying white space above/under the glyphs. To reduce the white space, web developers may use line-height < font-size (which causes overlapping focusables...).

Test 1 (the red and blue links intersect the purple link below):

Aaaaaaaaaa unreachable, cccccccc ccc ccccccc
blabla, ddd ddd dddddd dddddd ddd ddd ddd bla.

Test 2 (the red and blue links intersect the purple link above):

blabla, ddd ddd dddddd dddddd ddd ddd ddd bla. Aaaaaaaaaa unreachable, cccccccc ccc ccccccc

Manual test instruction: Ensure that all links are reachable.