Inline-block with some content

Test passes if the bottom of the glyphs "P", "A", "S" and "S" are vertically aligned at the same vertical position.

P
1st A S
S

Inline-block withOUT content

Test passes if the bottom of the filled blue square is at the same vertical position as the bottom of glyphs "a" and "z".

a
z

Inline-block with underscore character as its content

Test passes if there is a black and white horizontal line traversing a blue filled square.

_______
1st _________
_______