one page top navigation codepen code example
Example: html in page navigation
Uses HTML's anchors:
<a href="#anch_start">INTRO</a>
<a href="#anch_end">ENDING</a>
'href' uses 'id' to find these segments:
<div class="intro" id="anch_start"></div>
<div class="epic_ending" id="anch_end"></div>