CSS max-width / min-width 实例

<style>
  .maxmin-demo {
    background-color: #e8e8e8;
    padding: 10px;
  }
  .maxmin-item {
    background-color: #2196F3;
    border: 1px solid #000;
    color: white;
    font-size: 18px;
    font-weight: bold;
    text-align: center;
    padding: 10px;
    margin: 5px 0;
  }
  .max-width {
    max-width: 300px;
    width: 100%;
  }
  .min-width {
    min-width: 500px;
    width: auto;
  }
</style>
<div class="maxmin-demo">