H5自带验证美化CSS
1、:require（必填）和:optional（选填）
<style>
.container{
max-width:400px;
margin:20px auto;
}
input,select,textarea{
width: 240px;
margin:10px 0;
border:1px solid #999;
padding: .5em 1em;
}
label{
color:#999;
margin-left: 10px;
}
input:required,textarea:required{
border-right:3px solid #aa0088;
}
input:optional,select:optional{
border-right:3px solid #999;
}
input:required +label::after{
content: "（必填）"
}
input:optional +label::after{
content: "（选填）"
}
input:focus,select:focus,textarea:focus{
outline:0;
}
input:required:focus,textarea:required:focus{
box-shadow: 0 0 3px 1px #aa0088;
}
input:optional:focus,select:required:focus{
box-shadow: 0 0 3px 1px #999;
}
input[type="submit"]{
background-color: #cc00aa;
border: 2px solid #aa0088;
padding:10px 0;
color:#fff;
}
input[type="submit"]:hover{
background-color:#aa0088;
}
</style>
</head>
<body>
<!-- <div class="contenteditable"></div> -->
<div class="container">
<form action="#">
<input type="name" required><label>名称</label>
<input type="email" required><label>邮箱</label>
<input type="tel"><label>手机</label>
<input type="url"><label>网址</label>
<select name="" id="">
<option value="">非必选项一</option>
<option value="">非必选项二</option>
<option value="">非必选项三</option>
<option value="">非必选项四</option>
</select>
<textarea name="#" cols="30" rows="10" placeholder="留言（必填）" required></textarea>
<input type="submit" value="提交表单">
</form>
</div>
2、:in-range和:out-of-range
3、:valid和:invalid 符合表单验证和不符合表单验证
<style>
.container{
margin:100px;
position:relative;
}
input{
border: 1px solid #999;
outline:0;
width:140px;
height:30px;
line-height:30px;text-indent:36px;transition: all .3s;
border-radius:5px;
}
span.title{
position:absolute;
line-height:30px;
height: 30px;
left:2px;
top:2px;
transition:all .3s;
}
input:focus,input:hover{
text-indent:2px;
}
input:focus+span.title,input:hover+span.title{
transform:translateX(-120%)
}
input:valid ~label::after{
content: "你输入正确！"
}
input:invalid ~label::after{
content: "你邮箱错误！"
}
input:valid{
border:1px solid green;
}
input:invalid{
border:1px solid red;
}
</style>
</head>
<body>
<div class="container">
<input id="mail" type="email" required placeholder="输入邮箱">
<span class="title">邮箱</span>
<label for="mail"></label>
</div>
4、:read-only和:read-write 代表input或者表单元素的标签
