#contenedor1{
    display: flex;
    background-color: #000;  
    height: 300px;
    color:white;
    font-size:2rem;
  }
  
  #item1 {  
    background-color: #0078A6;
  }
  #item2 {
    flex-grow: 1;
    background-color: #0084B6;
  }
  #item3 {
    background-color: #008CC1;
  }