Parent div not taking height of the children

by CreativeTechnocrayts CreativeTechnocrayts

HTML

<div class="wrapper">
        <div class="float-box">
        </div>
        <div class="float-box">
        
        </div>
        <div class="float-box">
        
        </div>
        <div class="float-box">
        
        </div>
        <div class="float-box">
        
        </div>
        <div class="float-box">
        
        </div>
    </div>

CSS

.wrapper{
     min-height: 20px;
     padding: 19px;
     margin-bottom: 20px;
     background-color: grey;
     border: 1px solid #e3e3e3;
     border-radius: 4px;
     -webkit-box-shadow: inset 0 1px 1px rgba(0, 0, 0, .05);
     box-shadow: inset 0 1px 1px rgba(0, 0, 0, .05);
     height: auto;
    }
    .float-box{
      height:100px;
     width:100px;
     float: left;
     text-align: center;
     border: 2px solid #eee;
     background:green;
    }