内阴影

HTML

<div class="box_shadow"></div>

CSS

.box_shadow {
  background-color: #1C90F3;
  width: 200px;
  height: 100px;
  margin: 50px;
  -webkit-box-shadow: inset 0px 0px 10px 0px #444444;
     -moz-box-shadow: inset 0px 0px 10px 0px #444444;
          box-shadow: inset 0px 0px 10px 0px #444444;
}

结果:

StackOverflow 文档

JSFiddle: https ://jsfiddle.net/UnsungHero97/80qod7aL/1/