12.写了一个怪怪的边框

效果图

DOM

<div class="shape-10 box">
            
</div>

css

.shape-10{
    
    background: yellowgreen;
    border: 10px dashed #655;
    outline: 5px dashed deeppink;
    outline-offset: -10px;
}
.box-shadow{
    height: 300px;
     534px;
    margin: 20px auto;
}