html - How does twitter bootstrap work internally -

i have basic understanding of css,html , better of scripting languages javascript,php... trying dive bootstrap framework. documentation great, problems without creating pages, works pretty well.

but hate doing without understanding how work under hood internally.

i understand css3 used browser specific features, cannot leave is, want better understanding of bootstrap.
, how can implement same without using bootstrap.css.

i know best way read bootstrap.css maybe has link article or other resource explaining how stuff works , how achieved , can implement without bootstrap.

thanks.

the best way still reading bootstrap.css file. don't have read top bottom. pick sample web page made in bootstrap. see classes used where. bootstrap classes intuitive. probable you'll see classes like, .row, .col-sm-4, navbar, .container, .container-fluid etc. next step search particular class in bottstrap.css. e.g. searching .col- you'll see there 12 different classes starting .col-sm-1 .col-sm-12 after media query <= 768px. other screen size you'll see other classes .col-xs-1 .col-xs-12 screen sizes >= 768px , on. give 100% width .coll-*-12 , 50% width col-*-6 etc. you'll see clearfix classes etc. click. whenever you'll see new class used in page it's name self explaining foreguess class , how defined in framework.

that strategy using learn bootstrap. although feel of times need rudimentary classes of bootstrap responsiveness. simple things can done manually custom css, styling buttons, font-sizes etc.

finally i'd suggest following article undertanding how .row , .col work. 15px padding , -15px margin doing in these things.

http://www.helloerik.com/the-subtle-magic-behind-why-the-bootstrap-3-grid-works

---

p.s: if know how use developer tools looking through dom far better approach. can see css applied each class , can edit see how makes difference.