1、逐个设置
$("div").css("width","100px");
$("div").css("heigth","100px");
$("div").css("bacdground","red");
2、链式设置
$("div").css("width","100px").css("heigth","100px").css("bacdground","red");
3、批量设置
$("div").css({
"100px",
heigth:"100px",
bacdground:"red"
});