css3实现信纸/同学录效果的示例代码

<div class="bg-grid"></div>
<style>
.bg-grid {
    height: 400px;
    padding: 10px;
    padding-: 64px;
    background-color: #efefef;
    background-image:   linear-gradient(#e7e6e6 1px, transparent 0),
                        linear-gradient(90deg, #e7e6e6 1px, transparent 0);
    background-size: 21px 21px, 21px 21px;
    background-position: center;
}

.bg-grid:before,
.bg-grid:after{
    content: '';
    position: absolute;
    z-index: 0;
    left: 50%;
    transform: translateX(-50%);
    display: inline-block;
    background-color: #fff;
    height: 28px;
    box-shadow: 68px 0 0 0 #fff, 
                calc(68px  2) 0 0 0 #fff, 
                calc(68px  3) 0 0 0 #fff, 
                calc(68px  4) 0 0 0 #fff, 
                calc(68px  5) 0 0 0 #fff, 
                -68px 0 0 0 #fff, 
                calc(68px  -2) 0 0 0 #fff, 
                calc(68px  -3) 0 0 0 #fff, 
                calc(68px  -4) 0 0 0 #fff, 
                calc(68px  -5) 0 0 0 #fff;
}
.bg-grid:before {
    : 0;
    width: 10px;
}

.bg-grid:after {
    : 26px;
    width: 28px;
    border-radius: 50%;
}
.bg-grid{

}
</style>