شیب رنگ خطی از چپ به راست

#grad
{
background: -webkit-linear-gradient(left, red , blue); /* For Safari */
background: -o-linear-gradient(right, red, blue); /* For Opera 11.1 to 12.0 */
background: -moz-linear-gradient(right, red, blue); /* For Firefox 3.6 to 15 */
background: linear-gradient(to right, red , blue); /* Standard syntax */
}