Why is the one-page navigation code not working?

Question

JavaScript

Tell me, please, what am I doing wrong, why the last link to the section does not work (no matter how many section links)?
link to task in jsbin

Answer 1

Your href in the link does not match the data-section parameter:
<section class="section" data-section="go">

Answer 2

in the line dirPos = dirSection.offset().top;
fails with the error "Cannot read property 'top' of undefined"
i.e. dirSection.offset() returns undefined