grid-auto-flow: row dense 表示尽可能填充，而不留空白

.wrapper, .wrapper-1 {
  margin: 50px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  grid-gap: 10px 20px;
  grid-auto-rows: 50px;
}

.wrapper-1 {
  grid-auto-flow: row dense;
}