Businesses are greatly influenced by their environment. All the situational factors which determine day to day circumstances impact firms. So, businesses must constantly analyze the trade environment and the market. There are many strategic analysis tools that a firm can use, but some are more common.
CSS is a style language that defines layout of HTML documents. For example, CSS covers fonts, colours, margins, lines, height, width, background images, advanced positions and many other things. Just wait and see! HTML can be (mis-)used to add layout to websites.
Web design is done by a graphic designer, and its output is purely graphical (photoshop, illustrator, etc) Front end development is done by a developer or developers, its input is the output of the graphic designer, and its output is HTML (often generated by php/python/javascript) and CSS.