I found a bunch of similar questions, but did not see a solution to the problem.
In general, for example, there is a button and it was asked to transition animation. Everything works, but it’s in chrome when you refresh the page that all the animations jump. For example, if the button has паддинги and the white color of the link is set, then when updating the page, the паддинги are animated from the standard to the specified sizes and the link color of the button from the standard blue or violet changes smoothly to white.
There is no such thing in the fox. you can set the animation only when :hover , and the problem goes away, but another one appears, when you remove the mouse from the button, it returns to the news \ to the standard specified sizes without animation.
body { background-color:#2e3436; } a { color:#ccc; text-decoration:none; } /*---------/// UP BUTTON ///---------*/ .upbtn { position: fixed; bottom:30px; left:30px; display:block; transition: 0.3s; transition-timing-function:ease-in-out; } .upbtn:hover{ transform: rotate(1deg); bottom:34px; } .upbtn a { border-radius:0 14px 0 14px; border:1px solid #ccc; padding: 5px 15px; opacity:0.3; transition: 0.3s; transition-timing-function:ease-in-out; } .upbtn a:hover { text-decoration:none; background-color:#ccc; color:#2e3436; opacity:1; padding: 7px 19px; } <div class="upbtn"><a href="#top"><b>▲ ВВЕРХ</b></a> </div>