freeCodeCamp/curriculum/challenges/chinese/01-responsive-web-design/applied-visual-design/animate-elements-at-variabl...

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id title challengeType videoUrl localeTitle
587d78a8367417b2b2512ae5 Animate Elements at Variable Rates 0 以可变速率动画元素

Description

有多种方法可以改变类似动画元素的动画速率。到目前为止,这是通过应用animation-iteration-count属性和设置@keyframes规则来实现的。为了说明,右侧的动画由两个“星星”组成,每个“星星”的大小和不透明度在@keyframes规则中的20标记处@keyframes ,从而创建闪烁动画。您可以更改其中一个元素的@keyframes规则,以便星星以不同的速率闪烁。

Instructions

通过将其@keyframes规则更改为50更改类名为star-1的元素的动画速率。

Tests

tests:
  - text: <code>star-1</code>类的<code>@keyframes</code>规则应为50
    testString: 'assert(code.match(/twinkle-1\s*?{\s*?50%/g), "The <code>@keyframes</code> rule for the <code>star-1</code> class should be 50%.");'

Challenge Seed

<style>
  .stars {
    background-color: white;
    height: 30px;
    width: 30px;
    border-radius: 50%;
    animation-iteration-count: infinite;
  }

  .star-1 {
    margin-top: 15%;
    margin-left: 60%;
    animation-name: twinkle-1;
    animation-duration: 1s;
  }

  .star-2 {
    margin-top: 25%;
    margin-left: 25%;
    animation-name: twinkle-2;
    animation-duration: 1s;
  }

  @keyframes twinkle-1 {
    20% {
      transform: scale(0.5);
      opacity: 0.5;
    }
  }

  @keyframes twinkle-2 {
    20% {
      transform: scale(0.5);
      opacity: 0.5;
    }
  }

  #back {
    position: fixed;
    padding: 0;
    margin: 0;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(black, #000099, #66c2ff, #ffcccc, #ffeee6);
  }
</style>

<div id="back"></div>
<div class="star-1 stars"></div>
<div class="star-2 stars"></div>

Solution

// solution required