CSS overview
Most modern web pages use external style sheets to control the presentation of a page.
Overriding style sheets from modules and base themes
You can override the style sheet provided by Drupal core, contributed modules or even other themes.
Adding style sheets from .info files
This page explains how to add a style sheet using the .info file of a theme. To add a style sheet programmatically, see the API functions
Adding CSS to form or page with attachments
On previous page we learn how to add css using .info file and drupal_add_css(). Adding custom CSS to a page is easy in Drupal, but can be a
Adding styles through the API
Adding styles through the .info file should be sufficient for most themes. Since the .info file is static, style sheets cannot be added
Live_css with .less support
Theming in Drupal has come a long way and the tools now available not only make theming easy but you can style your site very quickly.
Sass techniques and tools
Sass is a meta-language on top of CSS that’s used to describe the style of a document cleanly and structurally, with more power than flat
Standard Drupal core styles and classes
Drupal core takes a modular approach to CSS classes for standard page elements. A number of classes occur throughout a Drupal site. This
Using .clearfix
Drupal 6's “clear-block” class was a Drupalism for functionality which is better known by the CSS Community as “clearfix.” Furthermore,
Supporting "right to left" (RTL) languages
Adding support for RTL (Right to Left) languages involves overriding the lateral styles through cascades and naming the file based on the