为什么在Div周围没有CSS阴影效果

Question

比方说，我有一个像这样的div：

我想为这个div制作这个effect。所以我用了这些代码：

#myTypingText {
  width: 700px;
  height: 120px;
  padding: 12px;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 16px;
  line-height: 1.5em;
}

.description {
  margin: 20%;
  width: 100%;
  height: 180px !important;
  margin: auto;
  font-size: 20px;
}

.description p {
  margin: 50px 0px;
}

.block {
  position: relative;
  /* margin:25vh auto; 
            width:50%;
            min-width:320px;
            min-height:320px; */
  background: linear-gradient(0deg, #000, #262626);
  color: #f2f2f2;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.description:before,
.description:after {
  content: '';
  position: absolute;
  top: -2px;
  left: -2px;
  width: calc(100% + 4px);
  height: calc(100% + 4px);
  background: linear-gradient(45deg, #fb0094, #0000ff, #00ff00, #ffff00, #ff0000, #fb0094, #0000ff, #00ff00, #ffff00, #ff0000);
  background-size: 400%;
  z-index: -1;
  animation: shadow 20s linear infinite;
  top: -8px;
  left: -8px;
  width: calc(100% + 8px);
  height: calc(100% + 8px);
  filter: blur(24px);
  opacity: 0.9;
}

@keyframes shadow {
  0% {
    background-position: 0 0;
  }
  50.01% {
    background-position: 200% 0;
  }
  100% {
    background-position: 0 0;
  }
}

<div class="description block shadow" id="myTypingText"></div>

我只是该Codepen的每一行代码，但是当我加载页面时，它看起来像这样：

如您所见，颜色和动画的确出现在div周围，实际上，它填充了div，而我不希望这样。

所以，如果您知道如何解决此问题，请告诉我，我真的很感谢你们的任何建议...

Answer 1

您的CSS代码中的某些内容正在删除此属性：

.block {
  /* ... */
  background: linear-gradient(0deg, #000, #262626);
}

因此，在不删除/更改它的情况下，它必须看起来像这样：

#myTypingText {
    width:700px;
    height:120px;
    padding:12px;
    font-family:Arial, Helvetica, sans-serif;
    font-size:16px;
    line-height:1.5em;
}
.description{
    margin: 20%;
    width:100%;
    height:180px !important;
    margin:auto;
    font-size:20px;
}

.description p{
    margin:50px 0px;
}

.block {
    position: relative;
    /* margin:25vh auto; 
    width:50%;
    min-width:320px;
    min-height:320px; */
    background: linear-gradient(0deg, #000, #262626);
    color:#f2f2f2;
    display: flex;
    flex-direction: column;
    justify-content: center;
  }

  .description:before,
  .description:after{
      content:'';
      position: absolute;
      top:-2px;
      left:-2px;
      width:calc(100% + 4px);
      height:calc(100% + 4px);
      background: linear-gradient(45deg, #fb0094, #0000ff, #00ff00, #ffff00, #ff0000, #fb0094, #0000ff, #00ff00, #ffff00, #ff0000);
      background-size: 400%;
      z-index:-1;
      animation: shadow 20s linear infinite;
      top:-8px;
      left:-8px;
      width:calc(100% + 8px);
      height:calc(100% + 8px);    
      filter:blur(24px);
      opacity:0.9;
    }


  @keyframes shadow {
    0% {
      background-position: 0 0;
    }
    50.01% {
      background-position: 200% 0;
    }
    100% {
      background-position: 0 0;
    }
  }
      
/*
.block{
   background-image: none;
   background-color: rgba(255,255,255,0.2);
}
*/

<div class="description block shadow" id="myTypingText"></div>

如果我取消注释最后一条CSS规则，则会看到与您相同的效果：

#myTypingText {
    width:700px;
    height:120px;
    padding:12px;
    font-family:Arial, Helvetica, sans-serif;
    font-size:16px;
    line-height:1.5em;
}
.description{
    margin: 20%;
    width:100%;
    height:180px !important;
    margin:auto;
    font-size:20px;
}

.description p{
    margin:50px 0px;
}

.block {
    position: relative;
    /* margin:25vh auto; 
    width:50%;
    min-width:320px;
    min-height:320px; */
    background: linear-gradient(0deg, #000, #262626);
    color:#f2f2f2;
    display: flex;
    flex-direction: column;
    justify-content: center;
  }

  .description:before,
  .description:after{
      content:'';
      position: absolute;
      top:-2px;
      left:-2px;
      width:calc(100% + 4px);
      height:calc(100% + 4px);
      background: linear-gradient(45deg, #fb0094, #0000ff, #00ff00, #ffff00, #ff0000, #fb0094, #0000ff, #00ff00, #ffff00, #ff0000);
      background-size: 400%;
      z-index:-1;
      animation: shadow 20s linear infinite;
      top:-8px;
      left:-8px;
      width:calc(100% + 8px);
      height:calc(100% + 8px);    
      filter:blur(24px);
      opacity:0.9;
    }


  @keyframes shadow {
    0% {
      background-position: 0 0;
    }
    50.01% {
      background-position: 200% 0;
    }
    100% {
      background-position: 0 0;
    }
  }
      

.block{
   background-image: none;
   background-color: rgba(255,255,255,0.2);
}

<div class="description block shadow" id="myTypingText"></div>