border css property
Border color border-color: red / # ffffff / rgb () defaults to black
Border style border-style: solid (the solid line) Dashed (broken line), the default is none
Border thickness border-width: 1
Border的简写 border：border-width border-style border-color；
Div cassette block
1, is the tag name, no special tag attributes
2, is mainly used The layout of
3, the width is 100%, chrome browser has 8px outside pitch default, clear this with 8px
4, this naturally occupy a width of 100% of the label we call it block-level elements.
For example, div p h1-h6 ul ol li, etc.
Features: width and height may be provided on a separate line.
5, the size of the width and height is not 100%, the number of decisions in accordance with the size of the contents of this label called introverted element (row-level elements)
For example, a span
Features: No one row alone can not set the width and height.
