.container {
  display: grid;
  grid-template-columns: 150px auto 100px;
  grid-template-rows: 50px calc(100% - 80px) 30px;
}

header {
  background: rgba(255,0,0,.3);
  grid-column: 1/4;
}
article {
  background: rgba(0,255,0,.3);
  grid-column: 1/3;
}
aside {
  background: rgba(0,0,255,.3);
}
footer {
  background: rgba(255,255,0,.3);
  grid-column: 1/4;
}
.container {
  padding: 10px;
  border: 1px solid #999;
  height: 300px;
}