Your user interface on a mobile phone looked okay. But I got an error, :"You are required to complete the following fields: - City". After re-trying on a desktop browser, I saw that the UI on a mobile browser was an accident by your development team. Your server didn't detect a mobile fingerprint. It appears you've made no effort at all to accommodate mobile phones. If you choose to leave things as they are, I would suggest a border around the donor ID fields that would indicate to the user that there is more content to the right. Until, or unless you choose to do that, your mobile users deserve a fair warning that your site is for desktop and tablet browsers only.