day05-苏宁易购导航html

布局

transition:all .5s;/*在0.5秒内完成所有改变的动作*/

/*白色遮罩*/

.white{

    width:100%;

    height:2px;

    background:white;

    position:absolute;

    display:none;   

}

    display:none;

.head_nav_ul>li:hover .o{background-color:white;

    outline:1px solid #dddddd;/*outline做为内边，不占据大小*/}

.head_nav_ul>li:hover .jiantou{transform:rotate(-180deg);}

.head_nav_ul>li:hover .side_nav{

    display:block;background:white;top:35px;}

.head_nav_ul>li:hover .white{display:block;z-index:99;}