CSS

1. block element:

   • dev
   • p
   • form
   • header
   • footer
   • section

2. inline

   • span
   • a

3. none

   • none

   none will not render the element while hidden will occupy current layout normally

Though mainstream tags remains unchanged style, we can modify the individual style for own purpose, such as, we will make li as inline element when horizontal nav.

1. width
   when dealing with width narrower than our control, the browser will determine how to display these element on window.

#main{    max-width:600px;    margin:0 auto;}

On account of padding and margin, the final appearance looks like different from what we see.

the physical constricts of width power on the central on box content, however, the layout of outside reaches turn out more significant, that is, if we want to limit on box edges directly, we should use box-sizing:border-gox instead.