CSS saves time : You can write CSS once and reuse same sheet in multiple HTML pages.
Easy Maintainence : To make a global change simply change the style, and all elements in all the webpages will be updated automatically.
Search Engines : CSS is considered as clean coding technique, which means search engines won’t have to struggle to “read” its content.
Superior styles to HTML : CSS has a much wider array of attributes than HTML, so you can give a far better look to your HTML page in comparison to HTML attributes.
Offline Browsing : CSS can store web applications locally with the help of offline catche.Using of this we can view offline websites.