.form{width:95%; background:#E5E5E5; margin:10px; auto;}
.form span{width:65px;height:35px;line-height:35px; text-align:center;float:left;}
.form input{height:35px;width:calc(100% - 100px);float:right;border:1px solid #E5E5E5;padding:0 10px; }
.form textarea{width:calc(100% - 100px);float:right;height:85px;border:1px solid #E5E5E5;padding:5px 10px;}
.btn{display:block;width:100%;height:50px;line-height:40px;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: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}