grid 布局

css

html, body {
  height: 100%;
  margin: 0;
}

.app {
  height: 100%;
  display: grid;
  grid-template-rows: 45px 1fr;
  grid-template-columns: 200px 1fr;
}

header {
  box-shadow: 0 2px 5px rgba(0, 0, 0, .16);
  /* stretch from first grid line to last grid line */
  grid-column: 1/-1;
}

aside {
  background-color: #213e48;
}