CSS Workaround using Polyfill

Oct 13, 2025 by miodeya.com 110 views

**Is there a way to select an open select box in CSS?** =====================================================

Introduction

When working with HTML select boxes, it can be challenging to style them using CSS, especially when it comes to selecting an open select box. In this article, we will explore the possibilities of selecting an open select box in CSS and provide you with the necessary code snippets to achieve this.

Background

When you set the webkit-appearance attribute to none on a select box, you can style it using CSS. However, when the option list is opened, you may want to display a different background image, such as an arrow pointing up. This is where the challenge lies.

Q&A

Q: Can I select an open select box in CSS?

A: Unfortunately, it is not possible to select an open select box in CSS using a simple selector. The :open pseudo-class is not supported in most browsers, and even if it were, it would not work as expected.

Q: What are my options?

A: There are a few workarounds you can use to achieve the desired effect:

1. Use JavaScript

You can use JavaScript to add a class to the select box when it is opened. This class can then be used to style the select box with a different background image.

2. Use the `:focus` pseudo-class

You can use the :focus pseudo-class to style the select box when it is focused. However, this will only work when the select box is focused, not when it is opened.

3. Use a polyfill

You can use a polyfill to add support for the :open pseudo-class to older browsers.

Q: How do I implement these workarounds?

A: Here are some code snippets to help you implement these workarounds:

Using JavaScript

document.addEventListener('DOMContentLoaded', function() {
  var selectBoxes = document.querySelectorAll('select');
  selectBoxes.forEach(function(selectBox) {
    selectBox.addEventListener('focus', function() {
      this.classList.add('open');
    });
    selectBox.addEventListener('blur', function() {
      this.classList.remove('open');
    });
  });
});

select.open {
  background-image: url('arrow-up.png');
}

Using the `:focus` pseudo-class

select:focus {
  background-image: url('arrow-up.png');
}

Using a polyfill

You can use a polyfill like css-polyfill to add support for the :open pseudo-class to older browsers.

Q: Are there any browser compatibility issues?

A: Yes, there are browser compatibility issues to consider when using these workarounds. For example:

The :focus pseudo-class may not work as expected in older browsers.
The css-polyfill polyfill may not work in all browsers.
The JavaScript workaround may not work in browsers that do not support the classList property.

Q: What are the best practices for styling select boxes?

A: Here are some best practices for styling select boxes:

Use the webkit-appearance attribute to style the select box.
Use a background image to style the select box.
Use a polyfill to add support for the :open pseudo-class to older browsers.
Use JavaScript to add a class to the select box when it is opened.

Conclusion

Selecting an open select box in CSS can be challenging, but there are workarounds available. By using JavaScript, the :focus pseudo-class, or a polyfill, you can achieve the desired effect. However, be aware of the browser compatibility issues and best practices for styling select boxes.

Additional Resources

Code Snippets

JavaScript workaround
CSS workaround using :focus pseudo-class
CSS workaround using polyfill

JavaScript Workaround

document.addEventListener('DOMContentLoaded', function() {
  var selectBoxes = document.querySelectorAll('select');
  selectBoxes.forEach(function(selectBox) {
    selectBox.addEventListener('focus', function() {
      this.classList.add('open');
    });
    selectBox.addEventListener('blur', function() {
      this.classList.remove('open');
    });
  });
});

CSS Workaround using `:focus` pseudo-class

select:focus {
  background-image: url('arrow-up.png');
}

CSS Workaround using Polyfill

@supports (open: open) {
  select:open {
    background-image: url('arrow-up.png');
  }
}

Note: The above code snippets are just examples and may need to be modified to fit your specific use case.