Friends, Cascading Style Sheets are the files in which properties and their corresponding values are written which is essential for HTML document to have a great USER-EXPERIENCE and RESPONSIVE-DESIGN that is, a website-project which provides a distinct features of a complete website section-wise with PHOTOGRAPHS and TEXTS.
Here, I'm going to write few questions which provides you an idea of the usage of Cascading Style Sheets to style the elements of a HTML-Document. H.T.M.L. is 'HyperText MarkUp Language'.
	- Learn the concept of border CSS-Property with Example;
 
	- Learn the complete concept of margin CSS-Property;
 
	- How to use background-image and background-repeat CSS-Properties;
 
	- Background Position/Background Size/Background Attachment;
 
	- Usage of rgb() and rgba()  to set background-color of an HTML element;
 
	- Applying of Box-Shadow to an HTML element;
 
	- What is text-shadow in CSS and How to use it;
 
	- How to use Overflow-Properties in CSS;
 
	- How to use Translate Function CSS-Transform Property;
 
	- How to use Skew Function CSS-Transform Property;
 
	- How to use Rotate Function CSS-Transform Property;
 
	- How to use Scale Function CSS-Transform Property;
 
	- CSS Position Properties Absolute-&-Relative;
 
	- CSS Position Properties Fixed-&-Sticky;
 
	- CSS Column Properties Column-count, Column-fill & Column-gap;
 
	- CSS Column Properties Column-rule, Column-span & Column-width;
 
	- CSS Opacity and Transition Property with Example;
 
	- CSS Display Properties Display-none, Display-block, Display-inline;
 
	- CSS Display Properties Display inline-block, Display-flex, Display List-item;
 
	- CSS Properties Resize and Text-indent;
 
	- CSS3 Animation Properties;
 
	- @keyframes, animation-name, animation-duration, animation-delay;
 
	- Iteration-count, direction, fill-mode;
 
	- Timing animation properties;
 
	- CSS Grid Properties Display-grid, row-gap, column-gap;
 
	- CSS Grid Properties Grid-column-start, column-end, row-start, row-end;
 
	- CSS3 Properties max-height, min-height, max-width, min-width.