表单样式优化：美观简洁的账号和步数输入

<style>
  form {
    display: flex;
    flex-direction: column;
    align-items: center;
    font-family: Arial, sans-serif;
    margin-top: 50px;
  }
  
  label {
    margin-right: 10px;
    font-size: 16px;
  }
  
  select,
  input[type=number] {
    padding: 10px;
    border: none;
    border-radius: 5px;
    font-size: 16px;
    margin-bottom: 10px;
  }
  
  select:focus,
  input[type=number]:focus {
    outline: none;
    box-shadow: 0 0 5px #6c63ff;
  }
  
  button[type=submit] {
    background-color: #6c63ff;
    color: #ffffff;
    padding: 10px 20px;
    border: none;
    border-radius: 5px;
    font-size: 16px;
    cursor: pointer;
    transition: background-color 0.2s ease-in-out;
  }
  
  button[type=submit]:hover {
    background-color: #5a4fcf;
  }
</style>
<form method='post' action='/submit'>
  <label for='select'>账号:</label>
  <select id='select' name='select'>
    <option value='option1'>option1</option>
    <option value='option2'>option2</option>
    <option value='option3'>option3</option>
  </select>
  <br>
  <label for='number'>步数:</label>
  <input type='number' id='number' name='number' min='20000' max='21000' value='${Math.floor(Math.random() * 1000) + 20000}'>
  <br>
  <button type='submit'>Submit</button>
</form>