.grid-container {
  display: grid;
  grid-template-areas: 
  "header header"
  "sidebar main";
  grid-template-columns: 300px 1fr;
  grid-template-rows: 70px 1fr;
  min-height: 100vh;
}

header {
  grid-area: header;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 20px;
  background-color: #4a6fa5;
  color: white;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
  position: sticky;
  top: 0;
  z-index: 100;
}

sidebar {
  grid-area: sidebar;
  background-color: white;
  padding: 20px;
  overflow-y: auto;
  box-shadow: 2px 0 5px rgba(0,0,0,0.05);
  transition: transform 0.3s ease;
  height: calc(100vh - 70px);
  position: sticky;
  top: 70px;
}

main {
  grid-area: main;
  padding: 30px;
  overflow-y: auto;
  background-color: #d5d5d5;
}