#container {
  display: grid;
  grid-template-columns: fit-content(300px) fit-content(300px) 1fr;
  grid-gap: 5px;
  box-sizing: border-box;
  height: 500px;
  width: 100%;
  background-color: #aabdaa;
  padding: 10px;
}

#container > div {
  background-color: #d4ffd4;
  padding: 5px;
}
img {
  width:10%;
  height:10%;
}