给选中的按钮设置css样式_css button 选中样式

function selectDate(btn) {
var num = $(btn).attr("num");
var selectStatus = $(btn).attr("select_status");
var selectDayPlan = $("#dayPlanSelect").find("option:selected");
if (selectStatus == "false") {
$(btn).css("background-color", color[selectDayPlan.attr("index")]);
} else {
$(btn).css("background-color", "#fff");
}
}