Actually, you don't need to modify any code: Just add data-toggle="collapse" and a data-target to element to automatically assign control of a collapsible element.
Drupal theme selection - This article provides you some tips how you can find the best Drupal themes on Envato Market / ThemeForest.
Drupal MD Alpine theme: How to increase the length of the title and description field of the Parallax
This howto explains how you can increase the length of the title field and description field of the Parallax 1 - 7
With „best“ I mean 1) unique design 2) easy customization/editing 3) SEO friendly 4) fully responsive 5) support most common contents 6) newest technologies.
This howto shows you how to disable the breadcrumb completely or for individual pages.
CSS modifications in style.css will be overwritten if you install a new version of a theme -> make modifications in an alternative .css file.
Step-by-step instructions how to choose, download and install a theme in Drupal 7.
Being able to modify a theme to suite your needs, it is essential to understand their basic elements: .info, .css and .php
Step-by-step instructions how to enable the Superfish menu within the Danland theme or Danblog subtheme (Drupal 7).
This tutorial shows you how to create a subtheme with the base theme we used before, Omega.