The size of the target for pointer inputs is at least 44 by 44 CSS pixels except when:
Equivalent
The target is available through an equivalent link or control on the same page that is at least 44 by 44 CSS pixels;
Inline
The target is in a sentence or block of text;
User Agent Control
The size of the target is determined by the user agent and is not modified by the author;
Essential
A particular presentation of the target is essential to the information being conveyed.
Function targets have a dimension of 44 × 44 px unless they have an equivalent link, are in a text, personalised or essential.