在同一行中对齐4个div，页边距为10px

<div class="container">
  <div class="box"></div>
  <div class="box"></div>
  <div class="box"></div>
  <div class="box"></div>
</div>

.container {
  display: flex;
  justify-content: space-between;
  margin: 10px;
}

.box {
  width: 100px;
  height: 100px;
  background-color: #ccc;
}