CSS3 introduced a new property - background-size - that enables you to change the size of background images. That means you can stretch your image horizontally, vertically, or both. You can resize it any way you wish.
This is the first thing to learn about jQuery: If you want an event to work on your page, you should call it inside the $(document).ready() function. Everything inside it will load as soon as the DOM is loaded and before the page contents are loaded.
The DIV movement of getting away from table-based design taught us that tables should be used only when you're presenting a table of data on your website, yet no CSS selector/rule was created to allow us to shade alternate rows a different color.
Dropdown menu going "behind" a flash movie, or staying on top of a lightbox layover. You have a CSS based drop-down menu in your navigation and a flash element near it the menus may get “hidden” behind the flash object.
Comments are piece of code which is ignored by any web browser. It is good practice to comment your code, especially in complex documents, to indicate sections of a document, and any other notes to anyone looking at the code.
The doctype declaration, which should be the first item to appear in the source markup of any web page, is an instruction to the web browser that identifies the version of the markup language in which the page is written.
Sass is an extension of CSS3, adding nested rules, variables, mixins, selector inheritance, and more. It’s translated to well-formatted, standard CSS using the command line tool or a web-framework plugin