阴影神器filter: drop-shadow

body {

    background: #ddd;

    font: 16px/1 sans-serif;

    }

div {

    margin: 100px;

    width: 200px;

    background: #fff;

    padding: 20px;

    position: relative;

        }

div:after {

    content: "";

    position: absolute;

    top: 50%;

    left: -10px;

    margin: -10px 0 0;

    border-right: 10px solid #fff;

    border-top: 10px solid transparent;

    border-bottom: 10px solid transparent;

        }

.box-shadow {

    box-shadow: 0 1px 5px rgba(0,0,0,.5);

        }

.filter-drop-shadow {

    -webkit-filter: drop-shadow(0 1px 5px rgba(0,0,0,.5));

    -moz-filter: drop-shadow(0 1px 5px rgba(0,0,0,.5));

    -ms-filter: drop-shadow(0 1px 5px rgba(0,0,0,.5));

    -o-filter: drop-shadow(0 1px 5px rgba(0,0,0,.5));

    filter: drop-shadow(0 1px 5px rgba(0,0,0,.5));

        }

<div class="box-shadow">

    box-shadow

</div>

<div class="filter-drop-shadow">

    filter: drop-shadow

</div>

（QQ/微信：314111741）：西安王尘宇 » 阴影神器filter: drop-shadow