input {
width:320px;
height:40px;
outline:none;
border:1px solid #DDDDDD;
padding-left:12px;
display:block;
margin:20px auto 0 auto;
}
.box {
width:500px;
height:500px;
margin:100px auto;
}
.btn {
width:260px;
height:40px;
border-radius:5px;
}
.orange {
background-color:orange!important;
color:#fff!important;
}
实时检测表单是否填写完毕,按钮禁用