7-5
                        欄寬隨著內容長度改變
                    
                
                                
	- 使用 col-{breakpoint}-auto, 欄寬隨著內容長度改變,但內容較少時,容器會靠左
 
	- 在row 加上 .justify-content-center :水平置中
 
<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>col-{breakpoint}-auto</title>
  <!-- Bootstrap CSS -->
  <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.2.0-beta1/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-0evHe/X+R7YkIZDRvuzKMRqM+OrBnVFBL6DOitfPri4tjfHxaWutUpFmBp4vmVor" crossorigin="anonymous">
</head>
<Style>
  html,
  body {
    height: 100%;
  }
  .container {
    border: 0px solid;
    background-color: #e5e5e5;
    min-height: 100%;
    height: 100%
  }
  .col {
    background-color: #ff0000;
    height: 50px;
    margin-top: 10px
  }
  .col-lg-2 {
    background-color: #ff9900;
    height: 50px;
    margin-top: 10px
  }
  .col-lg-auto {
    background-color: #ffffcc;
    height: 50px;
    margin-top: 10px
  }
</style>
<body>
  <div class="container">
    <div class="row ">
      <div class="col-lg-2">
        左欄<br>
        col-lg-2
      </div>
      <div class="col-lg-auto">
        空山不見人<br>
        col-lg-auto
      </div>
      <div class="col-lg-2">
        右欄<br>
        col-lg-2
      </div>
    </div>
    <div class="row">
      <div class="col">
        左欄<br>
        col
      </div>
      <div class="col-lg-auto">
        空山不見人,但聞人語響。返景入深林,復照青苔上。<br>
        col-lg-auto
      </div>
      <div class="col-lg-2">
        右欄<br>
        col-lg-2
      </div>
    </div>
  </div>
  <!-- Bootstrap JS -->
  <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.2.0-beta1/dist/js/bootstrap.bundle.min.js" integrity="sha384-pprn3073KE6tl6bjs2QrFaJGz5/SUsLqktiwsUTF55Jfv3qYSDhgCecCxMW52nD2" crossorigin="anonymous"></script>
</body>
</html>