如何为按钮添加平滑度？

Question

我有一个将页面向上抬起的按钮，但是当你点击它时，页面会急剧上升。我想增加平滑度。我该怎么做呢？我还想在向下滚动页面时添加此按钮的平滑外观

html

<button onclick="topFunction()" id="myBtn" title="Go to top">Top</button>

CSS

    #myBtn {
    display: none;
    position: fixed;
    bottom: 20px;
    right: 30px;
    z-index: 99;
    border: none;
    outline: none;
    background-color: red;
    color: white;
    cursor: pointer;
    padding: 15px;
    border-radius: 10px;
    font-size: 18px;
}

#myBtn:hover {
    background-color: #555;
}

js

    mybutton = document.getElementById("myBtn");

function scrollFunction() {
  console.log(document.body.scrollTop )
  console.log(document.documentElement.scrollTop)

  if (document.body.scrollTop > 20 || document.documentElement.scrollTop > 20)
    mybutton.style.display = "block";
  else
    mybutton.style.display = "none";
}

function topFunction() {
  document.body.scrollTop = 0;
  document.documentElement.scrollTop = 0;
}

window.onscroll = function() {
  scrollFunction()
}

scrollFunction();

Answer 1

将其添加到您的 CSS 中

html {
  scroll-behavior: smooth;
}