.demo-grid {
  display: grid;
  grid-template-areas: 
    "header header header"
    "sidebar main main"
    "footer footer footer";
  grid-template-columns: 150px 1fr 1fr;
  grid-template-rows: 60px 200px 60px;
  gap: 10px;
  height: 340px;
  background: #f0f0f0;
  padding: 10px;
  border-radius: 6px;
}

.demo-header {
  grid-area: header;
  background: #4CAF50;
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 4px;
  font-weight: bold;
}

.demo-sidebar {
  grid-area: sidebar;
  background: #2196F3;
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 4px;
  font-weight: bold;
}

.demo-main {
  grid-area: main;
  background: #FF9800;
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 4px;
  font-weight: bold;
}

.demo-footer {
  grid-area: footer;
  background: #9C27B0;
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 4px;
  font-weight: bold;
}