HTML5+CSS3实现超酷登录窗口(自动隐藏默认文本及判断必填字段)

效果非常不错的登录窗口，输入框获取焦点后会自动隐藏默认文本，如果为空会提示必填字段 ，经测试，效果相当不错，感兴趣的朋友可以参考下哈
在网页head区添加以下代码
[code]
<style>
html, body
{
height: 100%;
}
body
{
font: 12px 'Lucida Sans Unicode', 'Trebuchet MS', Arial, Helvetica;
margin: 0;
background-color: #d9dee2;
background-image: -webkit-gradient(linear, left top, left bottom, from(#ebeef2), to(#d9dee2));
background-image: -webkit-linear-gradient(top, #ebeef2, #d9dee2);
background-image: -moz-linear-gradient(top, #ebeef2, #d9dee2);
background-image: -ms-linear-gradient(top, #ebeef2, #d9dee2);
background-image: -o-linear-gradient(top, #ebeef2, #d9dee2);
background-image: linear-gradient(top, #ebeef2, #d9dee2);
}
/*--------------------*/
#login
{
background-color: #fff;
background-image: -webkit-gradient(linear, left top, left bottom, from(#fff), to(#eee));
background-image: -webkit-linear-gradient(top, #fff, #eee);
background-image: -moz-linear-gradient(top, #fff, #eee);
background-image: -ms-linear-gradient(top, #fff, #eee);
background-image: -o-linear-gradient(top, #fff, #eee);
background-image: linear-gradient(top, #fff, #eee);
height: 240px;
width: 400px;
margin: -150px 0 0 -230px;
padding: 30px;
position: absolute;
top: 50%;
left: 50%;
z-index: 0;
-moz-border-radius: 3px;
-webkit-border-radius: 3px;
border-radius: 3px;
-webkit-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);
-moz-box-shadow:
0 0 2px rgba(0, 0, 0, 0.2),
1px 1px 0 rgba(0, 0, 0, .1),
3px 3px 0 rgba(255, 255, 255, 1),
4px 4px 0 rgba(0, 0, 0, .1),
6px 6px 0 rgba(255, 255, 255, 1),
7px 7px 0 rgba(0, 0, 0, .1);
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: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;
}
/*--------------------*/
fieldset
{
border: 0;
padding: 0;
margin: 0;
}
/*--------------------*/
#inputs input
{
background: #f1f1f1 url(//www.sharejs.com/code/html5/login_form/login-sprite.png) no-repeat;
padding: 15px 15px 15px 30px;
margin: 0 0 10px 0;
width: 353px; /* 353 + 2 + 45 = 400 */
border: 1px solid #ccc;
-moz-border-radius: 5px;
-webkit-border-radius: 5px;
border-radius: 5px;
-moz-box-shadow: 0 1px 1px #ccc inset, 0 1px 0 #fff;
-webkit-box-shadow: 0 1px 1px #ccc inset, 0 1px 0 #fff;
box-shadow: 0 1px 1px #ccc inset, 0 1px 0 #fff;
}
#username
{
background-position: 5px -2px !important;
}
#password
{
background-position: 5px -52px !important;
}
#inputs input:focus
{
background-color: #fff;
border-color: #e8c291;
outline: none;
-moz-box-shadow: 0 0 0 1px #e8c291 inset;
-webkit-box-shadow: 0 0 0 1px #e8c291 inset;
box-shadow: 0 0 0 1px #e8c291 inset;
}
/*--------------------*/
#actions
{
margin: 25px 0 0 0;
}
#submit
{
background-color: #ffb94b;
background-image: -webkit-gradient(linear, left top, left bottom, from(#fddb6f), to(#ffb94b));
background-image: -webkit-linear-gradient(top, #fddb6f, #ffb94b);
background-image: -moz-linear-gradient(top, #fddb6f, #ffb94b);
background-image: -ms-linear-gradient(top, #fddb6f, #ffb94b);
background-image: -o-linear-gradient(top, #fddb6f, #ffb94b);
background-image: linear-gradient(top, #fddb6f, #ffb94b);
-moz-border-radius: 3px;
-webkit-border-radius: 3px;
border-radius: 3px;
text-shadow: 0 1px 0 rgba(255,255,255,0.5);
-moz-box-shadow: 0 0 1px rgba(0, 0, 0, 0.3), 0 1px 0 rgba(255, 255, 255, 0.3) inset;
-webkit-box-shadow: 0 0 1px rgba(0, 0, 0, 0.3), 0 1px 0 rgba(255, 255, 255, 0.3) inset;
box-shadow: 0 0 1px rgba(0, 0, 0, 0.3), 0 1px 0 rgba(255, 255, 255, 0.3) inset;
border-width: 1px;
border-style: solid;
border-color: #d69e31 #e3a037 #d5982d #e3a037;
float: left;
height: 35px;
padding: 0;
width: 120px;
cursor: pointer;
font: bold 15px Arial, Helvetica;
color: #8f5a0a;
}
#submit:hover,#submit:focus
{
background-color: #fddb6f;
background-image: -webkit-gradient(linear, left top, left bottom, from(#ffb94b), to(#fddb6f));
background-image: -webkit-linear-gradient(top, #ffb94b, #fddb6f);
background-image: -moz-linear-gradient(top, #ffb94b, #fddb6f);
background-image: -ms-linear-gradient(top, #ffb94b, #fddb6f);
background-image: -o-linear-gradient(top, #ffb94b, #fddb6f);
background-image: linear-gradient(top, #ffb94b, #fddb6f);
}
#submit:active
{
outline: none;
-moz-box-shadow: 0 1px 4px rgba(0, 0, 0, 0.5) inset;
-webkit-box-shadow: 0 1px 4px rgba(0, 0, 0, 0.5) inset;
box-shadow: 0 1px 4px rgba(0, 0, 0, 0.5) inset;
}
#submit::-moz-focus-inner
{
border: none;
}
#actions a
{
color: #3151A2;
float: right;
line-height: 35px;
margin-left: 10px;
}
/*--------------------*/
#back
{
display: block;
text-align: center;
position: relative;
top: 60px;
color: #999;
}
</style>
[/code]
在网页body区添加以下代码
[code]
<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>
<a href="//www.sharejs.com/subject/1599" id="back">Back to article...</a>
</form>
<!-- BSA AdPacks code -->
<script src="//code.jquery.com/jquery-1.6.3.min.js"></script>
<script>
(function(){
var bsa = document.createElement('script');
bsa.async = true;
bsa.src = '//www.sharejs.com/code/html5/login_form/adpacks-demo.js';
(document.getElementsByTagName('head')[0]||document.getElementsByTagName('body')[0]).appendChild(bsa);
})();
</script>
[/code]