答案 0 :(得分:2)
使用线性渐变 css函数:
hr {
height: 2px;
border: 0;
background: linear-gradient(to right, rgba(65, 191, 255, 0), rgba(65, 191, 255, 1), rgba(65, 191, 255, 0));
}

<hr />
&#13;
参考:
http://www.w3schools.com/css/css3_gradients.asp
https://developer.mozilla.org/en-US/docs/Web/CSS/linear-gradient