Adjust "more" span position

Greetings,

I’m trying to adjust the position of the span used as an anchor when accessing an article detail because the content get chopped by the header.

For example here :
http://www.wkd4496.net/retrogaming-room-sega-genesis/#more-622

The title “High Definition Graphics […]” is partially hidden by the header. So I would like to adjust the span position so the page will scroll at the correct height.

<span id="more-622"></span>

I’m using a Twenty Fourteen child theme.

My guess is I have to change the way the span is generated to add it some CSS class and make some adjustments? How does the theme normally deal with this?

Thank you.