html fade header line

index.html

<div class="fade-line" />

style.css

.fade-line {
        height: 1px;
        background-color: #E6E6E6;
        width: 66.0em;
        margin: 0 auto;
        background-image: linear-gradient(left , white 2%, #E6E6E6 50%, white 98%);
        background-image: -o-linear-gradient(left , white 2%, #E6E6E6 50%, white 98%);
        background-image: -moz-linear-gradient(left , white 2%, #E6E6E6 50%, white 98%);
        background-image: -webkit-linear-gradient(left , white 2%, #E6E6E6 50%, white 98%);
        background-image: -ms-linear-gradient(left , white 2%, #E6E6E6 50%, white 98%);
        background-image: -webkit-gradient( linear, left bottom, right bottom, color-stop(0.02, white), color-stop(0.5, gray), color-stop(0.98, white) );
        -webkit-print-color-adjust: exact; // to allow background appear in printed pdf
}