CSS Grid布局-命名区域

<style>
  .grid {
    display: grid;
    grid-template-areas:
      "header header header"
      "sidebar main main"
      "footer footer footer";
    grid-template-columns: 200px 1fr 1fr;
    grid-template-rows: 80px 1fr 60px;
    gap: 10px;
    background-color: #e8e8e8;
    padding: 10px;
    min-height: 400px;
  }
  .grid-item {
    border: 1px solid #000;
    color: white;
    font-size: 20px;
    font-weight: bold;
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
  }
  .header {