Css3 arrows using border
jQuery 1.9.1, HTML, CSS, JavaScript
author(s): Torstein Hønsi
Source from http://webthemex.com/webslidemenu/webslide/mobile-drawer-style-menu/dynamic-submenu-indicator-menu/index.html
jQuery 1.11.0, HTML, CSS, JavaScript
author(s): Black Label
Para prevenir que el elemento fixed no se desborde del elemento padre, te presento es solución.
Showing different regions
No-Library (pure JS), HTML, CSS, JavaScript