CSS3-Box-shadow阴影效果用法趣味讲解

CSS设置：
box-shadow:2px 2px 5px #000;

CSS设置：
box-shadow:0px 0px 10px #000;

CSS设置：
box-shadow:inset 2px 2px 5px #000;

CSS设置：
box-shadow:0px 0px 5px 10px #000;

CSS设置：
box-shadow:0px 15px 10px -15px #000;

CSS设置：
box-shadow:inset 0px 15px 10px -15px #000;

CSS设置：
box-shadow:0px 0px 0px 3px #bb0a0a,
0px 0px 0px 6px #2e56bf,
0px 0px 0px 9px #ea982e;

HTML代码：
<div class="box11 shadow lazy "></div>
CSS设置：

.box11 {
width: 300px;
height: 100px;
background: #ccc;
border-radius: 10px;
margin: 10px;
}

.shadow {
position: relative;
max-width: 270px;
box-shadow: 0px 1px 4px rgba(0,0,0,0.3),
0px 0px 20px rgba(0,0,0,0.1) inset;
}

.shadow::before,
.shadow::after {
content:"";
position:absolute;
z-index:-1;
}

.shadow::before,
.shadow::after {
content:"";
position:absolute;
z-index:-1;
bottom:15px;
left:10px;
width:50%;
height:20%;
}

.shadow::before,
.shadow::after {
content:"";
position:absolute;
z-index:-1;
bottom:15px;
left:10px;
width:50%;
height:20%;
box-shadow:0 15px 10px rgba(0, 0, 0, 0.7);
transform:rotate(-3deg);
}

.shadow::after{
right:10px;
left:auto;
transform:rotate(3deg);
}