when you scroll up then add active class for your every section
jQuery 3.4.1, HTML, CSS, JavaScript
jQuery 3.2.1, HTML, CSS, JavaScript
jQuery 3.3.1, HTML, CSS, JavaScript
jQuery 1.9.1, HTML, CSS, JavaScript
jQuery 1.10.1, HTML, CSS, JavaScript
jQuery 1.8.3, HTML, CSS, JavaScript
No-Library (pure JS), HTML, CSS, JavaScript
jQuery 2.1.0, HTML, CSS, JavaScript
Mootools 1.4.1, HTML, CSS, JavaScript