<style>
.demo.sha1{
box-shadow: 10px 10px 10px rgba(0,0,0,0.4);
-moz-box-shadow: 10px 10px 10px rgba(0,0,0,0.4);
-webkit-box-shadow: 10px 10px 10px rgba(0,0,0,0.4);
-o-box-shadow: 10px 10px 10px rgba(0,0,0,0.4);
-ms-box-shadow: 10px 10px 10px rgba(0,0,0,0.4);
}
</style>
<div class="c">
<div class="t">外側</div>
<div class="demo sha1"></div>
</div>
<style>
.demo.sha2{
box-shadow: 10px 10px 10px rgba(0,0,0,0.4) inset;
-moz-box-shadow: 10px 10px 10px rgba(0,0,0,0.4) inset;
-webkit-box-shadow: 10px 10px 10px rgba(0,0,0,0.4) inset;
-o-box-shadow: 10px 10px 10px rgba(0,0,0,0.4) inset;
-ms-box-shadow: 10px 10px 10px rgba(0,0,0,0.4) inset;
}
</style>
<div class="c">
<div class="t">内側</div>
<div class="demo sha2"></div>
</div>