Prefer the previous linear layout of Trello cards over the new layout? You can use a bookmarklet to inject styles into the DOM, reverting the layout to one wide column. Just create a new bookmark in your favorite browser’s bookmark bar and paste the following code for the link.

javascript:(function(){var style = document.createElement('style'); style.innerHTML = 'header ~ div[class] { display: block; overflow-y: auto !important; } header ~ div[class] main, header ~ div[class] main div, header ~ div[class] aside, header ~ div aside div { max-width: 100% !important; width: auto !important}'; document.head.appendChild(style);})();