.form{width:47%;float:left; background:#E5E5E5; margin:15px;}
.form span{width:140px;height:50px;line-height:50px; text-align:center;float:left;}
.form span img{margin-right:12px;vertical-align:middle}
.form input{height:50px;width:calc(100% - 190px);float:right;border:1px solid #E5E5E5;padding:0 20px;}
.form textarea{width:calc(100% - 190px);float:right;height:152px;border:1px solid #E5E5E5;padding:5px 20px;}
.btn{display:block;width:100%;height:50px;line-height:50px;text-align:center;background:#2d3e73;margin:0 auto;color:#fff;font-size:16px;border:0;outline:0;transition:.5s;cursor:pointer;position:relative;z-index:0;overflow: hidden;}
.btn.btn_tijiao img{margin-right:12px;vertical-align:middle}
.btn.btn_tijiao:before{content:"";position:absolute;z-index:-1;width:500px;height:500px;top:-160%;left:0%;background:#ff5454;transform:scale(0);transition:.3s ease-in-out;border-radius:50%;opacity:0}
.btn.btn_tijiao:hover:before{transform:scale(1);opacity:1}