Firefox的Linear Gradients (线性渐变)的简单演示

background-image:-moz-linear-gradient(right, #999999, #333333);
或
background-image:-moz-linear-gradient(right center , #999999, #333333);

background-image:-moz-linear-gradient(180deg, #999999, #333333);

background-image:-moz-linear-gradient(left, #999999, #333333);
或
background-image:-moz-linear-gradient(left center , #999999, #333333);

background-image:-moz-linear-gradient(0deg, #999999, #333333);

background-image:-moz-linear-gradient(top, #999999, #333333);
或
background-image:-moz-linear-gradient(center top , #999999, #333333);

background-image:-moz-linear-gradient(-90deg, #999999, #333333);
或
background-image:-moz-linear-gradient(270deg, #999999, #333333);

background-image:-moz-linear-gradient(bottom, #999999, #333333);
或
background-image:-moz-linear-gradient(center bottom, #999999, #333333);

background-image:-moz-linear-gradient(90deg, #999999, #333333);
或
background-image:-moz-linear-gradient(-270deg, #999999, #333333);