CSS preprocessing with LESS
Before applying CSS in the CompStore Magento theme, it is important to study CSS behavior in the Magento system. The stylesheets in Magento 2.0 are preprocessed and compiled to CSS using the LESS technology. LESS (http://lesscss.org/) is a CSS preprocessor that extends the CSS traditional features by including variables and functions to generate a powerful CSS code and saves the time in maintaining the code.
All the .less files that you will save in your theme are compiled by the LESS engine but you will always declare .css in the Magento theme frontend. Here are a couple of examples:
Frontend declaration: <
css src="css/styles.css" />Root source file:
<Magento _theme_dir>/web/css/styles.less
For further information, access the Magento 2.0 official documentation at http://goo.gl/XLkOcQ.
