.container {
  display: grid;
  grid-template-rows: max-content 1fr;
  grid-template-columns: max-content 1fr;
}

.header {
  grid-row: 1 / 2;
  grid-column: 1 / 3;
}

.menu {
  width: 300px;
  padding-right: 20px;
  border-right: 1px solid var(--base300);
  grid-row: 2/3;
  grid-column: 1 / 2;
}

.body {
  padding-left: 20px;
  grid-row: 2/3;
  grid-column: 2 / 3;
}