HTML5新增表单元素和表单属性，web前端开发项目文档

<label for="favcolor">选择你的喜好颜色:</label>
<input type="color" id="favcolor">

<label for="birthday">你的生日:</label>
<input type="date" id="birthday">

<label for="appointment">指定时间:</label>
<input type="time" id="appointment">

<label for="billing-month">计费月份:</label>
<input type="month" id="billing-month">

<label for="pick-week">选择周:</label>
<input type="week" id="pick-week">

<label for="quantity">数量:</label>
<input type="number" id="quantity" min="1" max="5" step="1">

<label for="search-input">搜索:</label>
<input type="search" id="search-input">

<label for="email-input">电邮:</label>
<input type="email" id="email-input">

<label for="phone-input">电话号码:</label>
<input type="tel" id="phone-input">

<label for="volume-control">音量控制:</label>
<input type="range" id="volume-control" min="1" max="100">

<label for="file-upload">选择多个文件:</label>
<input type="file" id="file-upload" multiple>

<input type="hidden" id="session-id" value="12345">

<label for="username">用户名:</label>
<input type="text" id="username" name="username" required>

<label for="credit-card">信用卡号:</label>
<input type="text" id="credit-card" name="credit-card" pattern="[0-9]{16}" title="输入16位数字">

<label for="username">用户名:</label>
<input type="text" id="username" name="username" placeholder="请输入用户名">

<label for="username">用户名:</label>
<input type="text" id="username" name="userna