1，checkbox和radio旁邊的文字不居中

        css: vertical-align:middle;margin-top:-2px;margin-bottom:1px;

2，loading的...動畫效果

       <span>...</span>

  span{

          display:inline-block;

          height:1em;

          line-height:1;

          overflow:hidden;            

}

span::before{

           content:'...\A..\A.';

           display:block;

           white-space:pre-wrap;

            animation:dot 1.5s infinite step-start  both;

}

@keyframes dot{

 33%{transform:translateY(-2em)}

 66%{transform:translateY(-1em)}

}