设置HTML表单的样式以将元素排列在一起

<form>
  <label for="name">姓名：</label>
  <input type="text" id="name" name="name" placeholder="请输入姓名">

  <label for="email">邮箱：</label>
  <input type="email" id="email" name="email" placeholder="请输入邮箱">

  <label for="message">留言：</label>
  <textarea id="message" name="message" placeholder="请输入留言"></textarea>

  <input type="submit" value="提交">
</form>

form {
  display: flex;
  flex-direction: column;
}

label {
  margin-bottom: 10px;
}

input, textarea {
  padding: 5px;
  margin-bottom: 10px;
}

input[type="submit"] {
  background-color: #007bff;
  color: #fff;
  border: none;
  padding: 10px 20px;
  cursor: pointer;
}