css - 边框凹陷效果怎么实现

Question

如图这种凹陷效果的分割线，用css3怎么实现

Answer 1

box-shadow:0 1px 0 rgba(0,0,0,.2) inset,0 -1x 0 rgba(255,255,255,.2) inset;
Exchanging 1px and -1px can raise; highlight The dark edge is translucent; there is no need to consider the color;

Answer 2

Hmm, thanks @golden_freeman_china for the tip.

box-shadow: inset 0 -1px 0 rgba( 255, 255, 250, 0.6), 
            inset 0 -2px 0 rgba( 0, 0, 0, 0.1);

Answer 3

:before,:after{
border:1px solid yellow;

}

This can be achieved by combining pseudo elements with two borders. The color of the two borders is the key