Learn CSS Variables by Building a City Skyline - Step 51

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Your code so far

<!-- file: index.html -->
<!DOCTYPE html>
<html lang="en">    
  <head>
    <meta charset="UTF-8">
    <title>City Skyline</title>
    <link href="styles.css" rel="stylesheet" />   
  </head>

  <body>
    <div class="background-buildings">
      <div></div>
      <div></div>
      <div class="bb1">
        <div class="bb1a bb1-window"></div>
        <div class="bb1b bb1-window"></div>
        <div class="bb1c bb1-window"></div>
        <div class="bb1d"></div>
      </div>
      <div class="bb2">
        <div class="bb2a"></div>
        <div class="bb2b"></div>
      </div>
      <div class="bb3"></div>
      <div></div>
      <div class="bb4"></div>
      <div></div>
      <div></div>
    </div>

    <div class="foreground-buildings">
      <div></div>
      <div></div>
      <div class="fb1"></div>
      <div class="fb2"></div>
      <div></div>
      <div class="fb3"></div>
      <div class="fb4"></div>
      <div class="fb5"></div>
      <div class="fb6"></div>
      <div></div>
      <div></div>
    </div>
  </body>
</html>
/* file: styles.css */
:root {
  --building-color1: #aa80ff;
  --building-color2: #66cc99;
  --building-color3: #cc6699;
  --building-color4: #538cc6;
  --window-color1: black;
  --window-color2: #8cd9b3;
}

* {
  border: 1px solid black;
  box-sizing: border-box;
}

body {
  height: 100vh;
  margin: 0;
  overflow: hidden;
}

.background-buildings, .foreground-buildings {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: flex-end;
  justify-content: space-evenly;
  position: absolute;
  top: 0;
}

/* BACKGROUND BUILDINGS - "bb" stands for "background building" */
.bb1 {
  width: 10%;
  height: 70%;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.bb1a {
  width: 70%;
}
  
.bb1b {
  width: 80%;
}
  
.bb1c {
  width: 90%;
}

.bb1d {
  width: 100%;
  height: 70%;
  background: linear-gradient(
      var(--building-color1) 50%,
      var(--window-color1)
    );
}

.bb1-window {
  height: 10%;
  background: linear-gradient(
      var(--building-color1),
      var(--window-color1)
    );
}

.bb2 {
  width: 10%;
  height: 50%;
  background-color: var(--building-color2);
}

/* User Editable Region */

.bb2b {
  width: 100%;
  height: 100%;
  background: linear-gradient(
    var(--building-color2) 0%,
    var(--building-color2) 6%,
    var(--window-color2) 6%,
    var(--window-color2) 9%,
  );
}

/* User Editable Region */

.bb3 {
  width: 10%;
  height: 55%;
  background-color: var(--building-color3);
}

.bb4 {
  width: 11%;
  height: 58%;
  background-color: var(--building-color4);
}

/* FOREGROUND BUILDINGS - "fb" stands for "foreground building" */
.fb1 {
  width: 10%;
  height: 60%;
  background-color: var(--building-color4);
}

.fb2 {
  width: 10%;
  height: 40%;
  background-color: var(--building-color3);
}

.fb3 {
  width: 10%;
  height: 35%;
  background-color: var(--building-color1);
}
  
.fb4 {
  width: 8%;
  height: 45%;
  background-color: var(--building-color1);
  position: relative;
  left: 10%;
}

.fb5 {
  width: 10%;
  height: 33%;
  background-color: var(--building-color2);
  position: relative;
  right: 10%;
}

.fb6 {
  width: 9%;
  height: 38%;
  background-color: var(--building-color3);
}
    

Your browser information:

User Agent is: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36

Challenge: Learn CSS Variables by Building a City Skyline - Step 51

Link to the challenge:

Look closely at the last line in the example. Notice that it doesn’t have a comma at the end. That comma (or lack thereof) actually makes a big difference in CSS. Commas separate lists of things, so having a comma at the end of the last line implies that there should be another line after that. But since there isn’t, your CSS doesn’t parse properly.

If you look at the preview pane, notice what change occurs when you remove/add the comma from the last line.