body {
  background-color: #3b404e;
  display: flex;
  justify-content: center;
  padding: 20px;
  font-family: Sans-Serif;
}

.item {
  background-color: #fff;
  color: #3b404e;
  border-radius: 0px;
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 18px;
  font-weight: normal;
}

.header {
  background-color: #fff;
}

.sidebar {
}

.content-1,
.content-2,
.content-3 {
}

.footer {
  background-color: #fff;
}

.container {
  display: grid;
  width: 750px;
  height: 600px;
  grid-template-columns: 200px 1fr 1fr;
  grid-template-rows: 80px 1fr 1fr 100px;
  grid-gap: 1rem;
  grid-template-areas:
      "header header header"
      "sidebar content-1 content-1"
      "sidebar content-2 content-3"
      "footer footer footer";
}

.header {
  grid-area: header;
}

.sidebar {
  grid-area: sidebar;
}

.content-1 {
  grid-area: content-1;
}

.content-2 {
  grid-area: content-2;
}

.content-3 {
  grid-area: content-3;
}

.footer {
  grid-area: footer;
  grid-row: 4 / 5;
  grid-column: 1 / 4;
}