div {
 padding: 20px;
 margin: 10px;
 float: left; 
}

#parental-div {
 width: 500px;
 background: #BDBAC2; 
}

#box-1 {
background: #5497FC; 
width: 70px;  
}

#box-2 {
background: #17A4BA; 
width: 70px;
  
}

#box-3 {
background: #84B12B;
width: 70px;  
}