html { font-family: sans-serif; } form { width: 600px; margin: 0 auto; } div { margin-bottom: 10px; } fieldset { background: cyan; border: 5px solid blue; } legend { padding: 10px; background: blue; color: cyan; } Copy to Clipboard JavaScript const otherCheckbox = document.querySelector('#other'); const otherText = document.querySelector('#otherValue'); otherText.style.visibility = 'hidden'; otherCheckbox.addEventListener('change', () => { if (otherCheckbox.checked) { otherText.style.visibility = 'visible'; otherText.value = ''; } else { otherText.style.visibility = 'hidden'; } });