currently the .innerdiv logo_red.png is affected by the opacity set in .outerdiv. How do I remove the opacity on the .innerdiv?

mycssfile.css

.outerdiv
{
  margin-left: auto; 
  margin-right: auto;
  margin-top: 40px;
  width: 800px;
  height: 150px;
  background-color: white;
  opacity: 0.5;
  border-radius: 5px;
}

.innerdiv
{
  background-image: url('logo_red.png');
  background-repeat: no-repeat;
  background-size: 290px 95px;
  position: absolute;
  top: 50px;
  left: 0;
  right: 0;
  height: 95px;
  width: 290px;
  margin-left: auto;
  margin-right: auto;
}