How to Create Collapsible Tree Menu with Pure CSS
Based on testing, this will work in any CSS3 selector supporting browser. It has been tested on Firefox 1+, Opera 9.6+, Safari 4+, iPhone/iPod Safari, Chrome 1+, Android and IE9+.
This technique will cater for a large amount of sub folders and files. It’s governed by your screen real estate and even then it’ll apply scroll bars to the document when the tree structure gets too long or wide.
Requirements: CSS3 selector supporting browser
License: License Free