Doubt at 'Basic CSS: Use a custom CSS Variable'

Can anyone please help me more about css variable, I passed this test on fcc but I didn’t understand how this challenge works. can anyone please help me to understand this css variable,

<style>
  .penguin {
    --penguin-skin: gray;
    position: relative;
    margin: auto;
    display: block;
    margin-top: 5%;
    width: 300px;
    height: 300px;
  }

  .penguin-top {
    top: 10%;
    left: 25%;

    /* Change code below this line */
    background:var(--penguin-skin);
    /* Change code above this line */

    width: 50%;
    height: 45%;
    border-radius: 70% 70% 60% 60%;
  }

  .penguin-bottom {
    top: 40%;
    left: 23.5%;

    /* Change code below this line */
    background: var(--penguin-skin);
    /* Change code above this line */

    width: 53%;
    height: 45%;
    border-radius: 70% 70% 100% 100%;
  }

  .right-hand {
    top: 0%;
    left: -5%;

    /* Change code below this line */
    background: var(--penguin-skin);
    /* Change code above this line */

    width: 30%;
    height: 60%;
    border-radius: 30% 30% 120% 30%;
    transform: rotate(45deg);
    z-index: -1;
  }

  .left-hand {
    top: 0%;
    left: 75%;

    /* Change code below this line */
    background: var(--penguin-skin);
    /* Change code above this line */

    width: 30%;
    height: 60%;
    border-radius: 30% 30% 30% 120%;
    transform: rotate(-45deg);
    z-index: -1;
  }

  .right-cheek {
    top: 15%;
    left: 35%;
    background: white;
    width: 60%;
    height: 70%;
    border-radius: 70% 70% 60% 60%;
  }

  .left-cheek {
    top: 15%;
    left: 5%;
    background: white;
    width: 60%;
    height: 70%;
    border-radius: 70% 70% 60% 60%;
  }

  .belly {
    top: 60%;
    left: 2.5%;
    background: white;
    width: 95%;
    height: 100%;
    border-radius: 120% 120% 100% 100%;
  }

  .right-feet {
    top: 85%;
    left: 60%;
    background: orange;
    width: 15%;
    height: 30%;
    border-radius: 50% 50% 50% 50%;
    transform: rotate(-80deg);
    z-index: -2222;
  }

  .left-feet {
    top: 85%;
    left: 25%;
    background: orange;
    width: 15%;
    height: 30%;
    border-radius: 50% 50% 50% 50%;
    transform: rotate(80deg);
    z-index: -2222;
  }

  .right-eye {
    top: 45%;
    left: 60%;
    background: black;
    width: 15%;
    height: 17%;
    border-radius: 50%;
  }

  .left-eye {
    top: 45%;
    left: 25%;
    background: black;
    width: 15%;
    height: 17%;
    border-radius: 50%;
  }

  .sparkle {
    top: 25%;
    left: 15%;
    background: white;
    width: 35%;
    height: 35%;
    border-radius: 50%;
  }

  .blush-right {
    top: 65%;
    left: 15%;
    background: pink;
    width: 15%;
    height: 10%;
    border-radius: 50%;
  }

  .blush-left {
    top: 65%;
    left: 70%;
    background: pink;
    width: 15%;
    height: 10%;
    border-radius: 50%;
  }

  .beak-top {
    top: 60%;
    left: 40%;
    background: orange;
    width: 20%;
    height: 10%;
    border-radius: 50%;
  }

  .beak-bottom {
    top: 65%;
    left: 42%;
    background: orange;
    width: 16%;
    height: 10%;
    border-radius: 50%;
  }

  body {
    background:#c6faf1;
  }

  .penguin * {
    position: absolute;
  }
</style>
<div class="penguin">
  <div class="penguin-bottom">
    <div class="right-hand"></div>
    <div class="left-hand"></div>
    <div class="right-feet"></div>
    <div class="left-feet"></div>
  </div>
  <div class="penguin-top">
    <div class="right-cheek"></div>
    <div class="left-cheek"></div>
    <div class="belly"></div>
    <div class="right-eye">
      <div class="sparkle"></div>
    </div>
    <div class="left-eye">
      <div class="sparkle"></div>
    </div>
    <div class="blush-right"></div>
    <div class="blush-left"></div>
    <div class="beak-top"></div>
    <div class="beak-bottom"></div>
  </div>
</div>

How --penguin-skin operates on this topic.

In .penguin class you’ve created a variable called --penguin-skin & stored a color value gray in that variable. Now you can use that variable in the css.

In .penguin-top, .penguin-bottom, .left-hand & .right-hand classes, the value of background property is set to var(--penguin-skin);. That means background will be gray.

This variable apporach is useful when you want to change the gray color to may be black. You’ve to just make the change in --penguin-skin class. Variable is just a like container where you can store something and use that in different places.

If you’ve studied any programming language (C, C++, Java, JavaScript etc.) before then you might have came accross the concept of variable. It’s similar to that.

2 Likes

I din’t have much knowledge in c, c++ but I got a some points from you thank you:) and how that -skin selector works? In html there is no class named skin but in css it’s changing color. How’s that possible!

1 Like

I’m glad I could help :heart:

Are you talking about -skin from --penguin-skin? penguin-skin is the entire name of the variable.

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yeah, so if i replace -skin in –pengiun-skin into –penguin-body does this works??

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Yes you can replace it. Make sure to replace every usage of --penguin-skin to --penguin-body in the css.