父容器样式必须有定义："{ display: -webkit-box }"
现象：水平时只能在一行布局，子容器在垂直方向上会填充父容器。
技巧：可以做水平居中和垂直居中。也可以实现经典的n列布局
说明：本文所用到的属性只在webkit内核的浏览器上做过测试
box-origin (horizontal)
The box-orient property specifies whether the children of a box should be laid out horizontally or vertically.
Children within a horizontal box are displayed from left to right, and children within a vertical box are displayed top to bottom. However, the box-direction and box-ordinal-group properties can change this ordering.
box-orient: horizontal|vertical|inline-axis|block-axis|inherit;
Default value: inline-axis
box-direction
The box-direction property specifies the direction in which child elements of a box element are laid out.
box-direction: normal|reverse|inherit;
reverse: Display the child elements in the reverse direction
Default value: normal
box-pack (水平方向)
The box-pack property specifies where child elements of a box are placed when the box is larger than the size of the children. This property specifies the horizontal position in horizontal boxes, and the vertical position in vertical boxes.
box-pack: start|end|center|justify;
Default value: start
box-align (垂直方向)
The box-align property specifies how to align the child elements of a box.
box-align: start|end|center|baseline|stretch;
Default value: stretch
box-flex (定义在子容器中)
The box-flex property specifies whether the child elements of a box is flexible or inflexible in size.
Elements that are flexible can shrink or grow as the box shrinks and grows. Whenever there is extra space in a box, flexible elements are expanded to fill that space.
box-flex: value;
Default value: 0.0 (indicates that the element is inflexible)
