CSS @keyframe Animation 移除整个按钮而不仅仅是边框

Question

我有一个 CSS 勾勒出按钮边框的关键帧动画。但是，当我尝试在鼠标关闭时反转动画时，它会删除插入框阴影而不是渐变边框。

正如您在下面看到的，我尝试在 mouseLeaveAnimationClass 中再次设置边框和背景。那也不能解决问题。这个问题有没有优雅的解决方案？

var els = document.querySelectorAll('.get-started');
for (var i = 0; i < els.length; i++) {
  els[i].addEventListener('mouseleave', function(e) {
    e.target.classList.add('mouseleaveAnimationClass');
  });
  els[i].addEventListener('mouseenter', function(e) {
    e.target.classList.remove('mouseleaveAnimationClass');
  });
}

 body {

   background-color: black;

 }

#button {
  display: flex;
  font-size: 2.5rem;
  color: white;
  align-items: center;
  justify-content: center;
  width: 250px;
  height: 75px;
  position: relative;
  top: -30%;
  left: calc(50% - 125px);
}

.get-started {
  --borderWidth: 5px;
  position: relative;
  border-radius: var(--borderWidth);
  background-color: #8551FF;
  box-shadow: inset 0 0 0 5px white;
  z-index: 1;
}

.get-started:after {
  content: '';
  position: absolute;
}

.get-started:hover:after {
  background: linear-gradient(60deg, #f79533, #f37055, #ef4e7b, #a166ab, #5073b8, #1098ad, #07b39b, #6fba82);
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  border-radius: 2px;
  background-size: 300% 300%;
  animation: frame-enter 1s forwards ease-in-out reverse, gradient-animation 4s ease-in-out infinite;
}

.get-started.mouseleaveAnimationClass {
  background: linear-gradient(60deg, #f79533, #f37055, #ef4e7b, #a166ab, #5073b8, #1098ad, #07b39b, #6fba82);
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  border-radius: 2px;
  background-size: 300% 300%;
  animation: frame-enter 1s forwards ease-in-out;
}


/* motion */

@keyframes gradient-animation {
  0% {
    background-position: 15% 0%;
  }
  50% {
    background-position: 85% 100%;
  }
  100% {
    background-position: 15% 0%;
  }
}

@keyframes frame-enter {
  0% {
    clip-path: polygon(0% 100%, 5px 100%, 5px 5px, calc(100% - 5px) 5px, calc(100% - 5px) calc(100% - 5px), 5px calc(100% - 5px), 5px 100%, 100% 100%, 100% 0%, 0% 0%);
  }
  25% {
    clip-path: polygon(0% 100%, 5px 100%, 5px 5px, calc(100% - 5px) 5px, calc(100% - 5px) calc(100% - 5px), calc(100% - 5px) calc(100% - 5px), calc(100% - 5px) 100%, 100% 100%, 100% 0%, 0% 0%);
  }
  50% {
    clip-path: polygon(0% 100%, 5px 100%, 5px 5px, calc(100% - 5px) 5px, calc(100% - 5px) 5px, calc(100% - 5px) 5px, calc(100% - 5px) 5px, calc(100% - 5px) 5px, 100% 0%, 0% 0%);
  }
  75% {
    -webkit-clip-path: polygon(0% 100%, 5px 100%, 5px 5px, 5px 5px, 5px 5px, 5px 5px, 5px 5px, 5px 5px, 5px 0%, 0% 0%);
  }
  100% {
    -webkit-clip-path: polygon(0% 100%, 5px 100%, 5px 100%, 5px 100%, 5px 100%, 5px 100%, 5px 100%, 5px 100%, 5px 100%, 0% 100%);
  }
}

<div class="get-started" id="button">Get Started</div>

Runnable Example

Answer 1

在您的原始问题中，.get-started.mouseleaveAnimationClass { 规则应用于元素本身，而不应用于 ::after 伪元素，这就是元素被剪裁的原因。但是，这不会解决您的主要问题 - 反向动画。

我已经用一个不是超级 DRY 的解决方案更新了你的代码，你可能可以改进它。

仅在第一次悬停时，.ready class 被添加到按钮。这会启用 frame-leave 动画，但不会运行。每当您 :hover 元素时，都会应用 frame-enter 动画，一旦您离开该元素，就会再次调用 frame-leave。

备注：

frame-enter和frame-leave是同一个动画。使用不同的名称可以让我们替换它们。
当你在动画中间进入然后离开时，它会从进入动画跳到离开动画。

var els = document.querySelectorAll('.get-started');
for (var i = 0; i < els.length; i++) {
  els[i].addEventListener('mouseenter', function(e) {
    e.target.classList.add('ready');
  }, { once: true });
}

#button {
  display: flex;
  font-size: 2.5rem;
  color: white;
  align-items: center;
  justify-content: center;
  width: 250px;
  height: 75px;
  position: relative;
  top: -30%;
  left: calc(50% - 125px);
}

.get-started {
  --borderWidth: 5px;
  position: relative;
  border-radius: var(--borderWidth);
  background-color: #8551FF;
  box-shadow: inset 0 0 0 5px white;
  z-index: 1;
}

.get-started::after {
  content: '';
  position: absolute;
  background: linear-gradient(60deg, #f79533, #f37055, #ef4e7b, #a166ab, #5073b8, #1098ad, #07b39b, #6fba82);
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  border-radius: 2px;
  background-size: 300% 300%;
  clip-path: polygon(0% 100%, 5px 100%, 5px 100%, 5px 100%, 5px 100%, 5px 100%, 5px 100%, 5px 100%, 5px 100%, 0% 100%);
}

.get-started.ready::after {
  animation: frame-leave 1s forwards ease-in-out, gradient-animation 4s ease-in-out infinite;
}

.get-started.ready:hover::after {
  animation: frame-enter 1s forwards ease-in-out reverse, gradient-animation 4s ease-in-out infinite;
}


/* motion */

@keyframes gradient-animation {
  0% {
    background-position: 15% 0%;
  }
  50% {
    background-position: 85% 100%;
  }
  100% {
    background-position: 15% 0%;
  }
}

@keyframes frame-enter {
  0% {
    clip-path: polygon(0% 100%, 5px 100%, 5px 5px, calc(100% - 5px) 5px, calc(100% - 5px) calc(100% - 5px), 5px calc(100% - 5px), 5px 100%, 100% 100%, 100% 0%, 0% 0%);
  }
  25% {
    clip-path: polygon(0% 100%, 5px 100%, 5px 5px, calc(100% - 5px) 5px, calc(100% - 5px) calc(100% - 5px), calc(100% - 5px) calc(100% - 5px), calc(100% - 5px) 100%, 100% 100%, 100% 0%, 0% 0%);
  }
  50% {
    clip-path: polygon(0% 100%, 5px 100%, 5px 5px, calc(100% - 5px) 5px, calc(100% - 5px) 5px, calc(100% - 5px) 5px, calc(100% - 5px) 5px, calc(100% - 5px) 5px, 100% 0%, 0% 0%);
  }
  75% {
    clip-path: polygon(0% 100%, 5px 100%, 5px 5px, 5px 5px, 5px 5px, 5px 5px, 5px 5px, 5px 5px, 5px 0%, 0% 0%);
  }
  100% {
    clip-path: polygon(0% 100%, 5px 100%, 5px 100%, 5px 100%, 5px 100%, 5px 100%, 5px 100%, 5px 100%, 5px 100%, 0% 100%);
  }
}

@keyframes frame-leave {
  0% {
    clip-path: polygon(0% 100%, 5px 100%, 5px 5px, calc(100% - 5px) 5px, calc(100% - 5px) calc(100% - 5px), 5px calc(100% - 5px), 5px 100%, 100% 100%, 100% 0%, 0% 0%);
  }
  25% {
    clip-path: polygon(0% 100%, 5px 100%, 5px 5px, calc(100% - 5px) 5px, calc(100% - 5px) calc(100% - 5px), calc(100% - 5px) calc(100% - 5px), calc(100% - 5px) 100%, 100% 100%, 100% 0%, 0% 0%);
  }
  50% {
    clip-path: polygon(0% 100%, 5px 100%, 5px 5px, calc(100% - 5px) 5px, calc(100% - 5px) 5px, calc(100% - 5px) 5px, calc(100% - 5px) 5px, calc(100% - 5px) 5px, 100% 0%, 0% 0%);
  }
  75% {
    clip-path: polygon(0% 100%, 5px 100%, 5px 5px, 5px 5px, 5px 5px, 5px 5px, 5px 5px, 5px 5px, 5px 0%, 0% 0%);
  }
  100% {
    clip-path: polygon(0% 100%, 5px 100%, 5px 100%, 5px 100%, 5px 100%, 5px 100%, 5px 100%, 5px 100%, 5px 100%, 0% 100%);
  }
}

<div class="get-started" id="button">Get Started</div>

CSS @keyframe Animation 移除整个按钮而不仅仅是边框

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