本文详细介绍使用HTML5 和CSS3 制作一个登录页面的完整过程。

View demo

login.html

    <form id="login"> 
        <h1>Log In</h1> 
        <fieldset id="inputs"> 
            <input id="username" type="text" placeholder="Username" autofocus required> 
            <input id="password" type="password" placeholder="Password" required> 
        </fieldset> 
        <fieldset id="actions"> 
            <input type="submit" id="submit" value="Log in"> 
            <a href="">Forgot your password?</a><a href="">Register</a> 
        </fieldset> 
    </form> 

所用到的HTML 5的特性：

◆ placeholder – 输入框的简短提示，当该输入框获得输入焦点时，该提示信息自动消失

◆ required – 指定该输入元素是否必须提供

◆ autofocus – 指定输入框是否在页面加载完毕自动获取输入焦点

◆ type=”password” – 指定密码输入(非HTML5专有)

CSS

在这里我们用到了 CSS3 的一些专有属性，包括：

Box-shadow 可以帮我们制作效果很好的边框阴影

    #login  
    {  
        box-shadow:  
              0 0 2px rgba(0, 0, 0, 0.2),  
              0 1px 1px rgba(0, 0, 0, .2),  
              0 3px 0 #fff,  
              0 4px 0 rgba(0, 0, 0, .2),  
              0 6px 0 #fff,  
              0 7px 0 rgba(0, 0, 0, .2);  
    } 

    #login  
    {  
        position: absolute;  
        z-index: 0;  
    }  
     
    #login:before  
    {  
        content: '';  
        position: absolute;  
        z-index: -1;  
        border: 1px dashed #ccc;  
        top: 5px;  
        bottom: 5px;  
        left: 5px;  
        right: 5px;  
        -moz-box-shadow: 0 0 0 1px #fff;  
        -webkit-box-shadow: 0 0 0 1px #fff;  
        box-shadow: 0 0 0 1px #fff;  
    } 

    h1  
    {  
        text-shadow: 0 1px 0 rgba(255, 255, 255, .7), 0px 2px 0 rgba(0, 0, 0, .5);  
        text-transform: uppercase;  
        text-align: center;  
        color: #666;  
        margin: 0 0 30px 0;  
        letter-spacing: 4px;  
        font: normal 26px/1 Verdana, Helvetica;  
        position: relative;  
    }  
     
    h1:after, h1:before  
    {  
        background-color: #777;  
        content: "";  
        height: 1px;  
        position: absolute;  
        top: 15px;  
        width: 120px;  
    }  
     
    h1:after  
    {  
        background-image: -webkit-gradient(linear, left top, right top, from(#777), to(#fff));  
        background-image: -webkit-linear-gradient(left, #777, #fff);  
        background-image: -moz-linear-gradient(left, #777, #fff);  
        background-image: -ms-linear-gradient(left, #777, #fff);  
        background-image: -o-linear-gradient(left, #777, #fff);  
        background-image: linear-gradient(left, #777, #fff);  
        right: 0;  
    }  
     
    h1:before  
    {  
        background-image: -webkit-gradient(linear, right top, left top, from(#777), to(#fff));  
        background-image: -webkit-linear-gradient(right, #777, #fff);  
        background-image: -moz-linear-gradient(right, #777, #fff);  
        background-image: -ms-linear-gradient(right, #777, #fff);  
        background-image: -o-linear-gradient(right, #777, #fff);  
        background-image: linear-gradient(right, #777, #fff);  
        left: 0;  
    } 

View demo

结论

在一些老的浏览器上也表现不错，下图是在IE8下的效果：

原文：http://www.oschina.net/question/5189_28155