Learn CSS Variables by Building a City Skyline - Step 40

Tell us what’s happening:
Describe your issue in detail here.

I am stuck on this step. The linear-gradient appears to be working in the preview, but it is not accepting my code. Any help would be greatly appreciated!

  **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"></div>
      <div class="bb1b"></div>
      <div class="bb1c"></div>
      <div class="bb1d"></div>
    </div>
    <div class="bb2"></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;
}

* {
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%;
height: 10%;
background-color: var(--building-color1);
background: linear-gradient(var(--building-color1), var(--window-color1));
}
.bb1b {
width: 80%;
height: 10%;
background-color: var(--building-color1);
}

.bb1c {
width: 90%;
height: 10%;
background-color: var(--building-color1);
}

.bb1d {
width: 100%;
height: 70%;
background-color: var(--building-color1);
}

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

.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/605.1.15 (KHTML, like Gecko) Version/14.0 Safari/605.1.15

Challenge: Learn CSS Variables by Building a City Skyline - Step 40

Link to the challenge:

not sure about this one, this line works for me

try to reset the step maybe

if it doesn’t help, try to pass it in another browser

Thank you. It must have been a problem with Safari. It worked fine when I tried in Chrome.