normal,icon,window,button,menu,field

span.app {
    appearance:icon;
    -webkit-appearance:icon;
    -moz-appearance:icon;
}

normal

icon

window

button

menu

field

BTW:

box-shadow: h-shadow v-shadow blur spread color inset;

顺序：水平位置，垂直文志，模糊大小，距离，颜色，是否 向内