background-color: #000;
filter: progid:DXImageTransform.Microsoft.gradient(startColorstr=‘#bbb‘, endColorstr=‘#000‘);
background-image: -webkit-gradient(linear, left top, left bottom, from(#bbb), to(#000));
background-image: -webkit-linear-gradient(top, #bbb, #000);
background-image: -moz-linear-gradient(top, #bbb, #000);
background-image: -ms-linear-gradient(top, #bbb, #000);
background-image: -o-linear-gradient(top, #bbb, #000);
background-image: linear-gradient(top, #bbb, #000);
CSS3渐变生成工具：CSS3 Gradient Generator、colorzilla
延伸学习教程：http://css-tricks.com/examples/CSS3Gradient/、http://www.w3cplus.com/content/css3-gradient（中文）
原文：http://www.cnblogs.com/kojya/p/4093376.html