css/css-item-layout/3-2.html

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8" />
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <title>法2：元素宽度未知，且所有元素都在一个容器</title>
  <meta name="viewport" content="width=device-width, initial-scale=1">

  <style>
    .wrapper {
      width: 391px;
      padding: 10px;
      margin: 150px auto;
      border: 2px solid rgb(240, 103, 103);
    }

    .container {
      display: flex;
      flex-wrap: wrap;
      margin-bottom: -20px;
      margin-right: -30px;
    }

    .item {
      margin-right: 30px;
      margin-bottom: 20px;
      padding: 5px 10px;
      font-size: 20px;
      border-radius: 5px / 5px;
      background: rgb(103, 164, 243);
    }
  </style>

</head>
<body>
  <div class="wrapper">
    <div class='container'>
      <div class='item'>两个才能成一行呀</div>
      <div class='item'>两个才能成一行呀</div>
      <div class='item'>这三个字</div>
      <div class='item'>四个</div>
      <div class='item'>独成一行呀独成一行呀独成一行呀独成</div>
      <div class='item'>两个才能成一行呀</div>
      <div class='item'>四个</div>
    </div>
  </div>
</body>
</html>