如何并排放置两个输入字段

<form>
  <label for="input1">输入字段1：</label>
  <input type="text" id="input1" name="input1"><br><br>
  
  <label for="input2">输入字段2：</label>
  <input type="text" id="input2" name="input2"><br><br>
  
  <input type="submit" value="提交">
</form>

form {
  width: 400px;
}

label, input {
  display: block;
  margin-bottom: 10px;
}

input[type="submit"] {
  display: inline-block;
  margin-top: 10px;
}