将box-shadow添加到:after伪元素之后

过滤器可以工作:

.shadowed {
    -webkit-filter: drop-shadow(0px 2px 2px rgba(130,130,130,1));
    filter        : drop-shadow(0px 2px 2px rgba(130,130,130,1));
    -ms-filter    : "progid:DXImageTransform.Microsoft.Dropshadow(OffX=0, OffY=2, Color='#444')";
    filter        : "progid:DXImageTransform.Microsoft.Dropshadow(OffX=0, OffY=2, Color='#444')";
}

工作示例:http://codepen.io/tolmark12/pen/JopNeR？editors = 110

了解更多信息:创建真正的跨浏览器投影

您可以添加另一个:伪元素,将其旋转45deg并添加box-shadow到其中.

更新小提琴

body {
  background: #eee
}
.testimonial-inner {
  background: #fff;
  -webkit-border-radius: 3px;
  -moz-border-radius: 3px;
  border-radius: 3px;
  padding: 30px;
  display: block;
  margin-bottom: 25px;
  position: relative;
  box-shadow: 0px 0px 5px 0px rgba(0, 0, 0, 0.75);
}
.testimonial-inner:after {
  top: 100%;
  left: 48px;
  border: solid transparent;
  content: " ";
  height: 0;
  width: 0;
  position: absolute;
  pointer-events: none;
  border-color: rgba(255, 255, 255, 0);
  border-top-color: #fff;
  border-width: 18px;
  margin-left: -18px;
}
.testimonial-inner:before {
  content: '';
  position: absolute;
  transform: rotate(45deg);
  width: 36px;
  height: 36px;
  bottom: -12px;
  z-index: -1;
  box-shadow: 0px 0px 5px 0px rgba(0, 0, 0, 0.75);
}

  

    
Using Facebook was unquestionably the best decision I could possibly have made at the point in my journalistic journey. It enabled me to share my fears, frustrations as well as successes.