:root {
    --building-color1: #aa80ff;
    --building-color2: #66cc99;
    --building-color3: #cc6699;
    --building-color4: #538cc6;
    --window-color1: #bb99ff;
    --window-color2: #8cd9b3;
    --window-color3: #d98cb3;
    --window-color4: #8cb3d9;
  }
  
  * {
    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;
  }
  
  .building-wrap {
    display: flex;
    flex-direction: column;
    align-items: center;
  }
  
  .window-wrap {
    display: flex;
    align-items: center;
    justify-content: space-evenly;
  }
  
  .sky {
    background: radial-gradient(
        closest-corner circle at 15% 15%,
        #ffcf33,
        #ffcf33 20%,
        #ffff66 21%,
        #bbeeff 100%
      );
  }
  
  /* BACKGROUND BUILDINGS - "bb" stands for "background building" */
  .bb1 {
    width: 10%;
    height: 70%;
  }
  
  .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%;
  }
  
  .bb2a {
    border-bottom: 5vh solid var(--building-color2);
    border-left: 5vw solid transparent;
    border-right: 5vw solid transparent;
  }
  
  .bb2b {
    width: 100%;
    height: 100%;
    background: repeating-linear-gradient(
        var(--building-color2),
        var(--building-color2) 6%,
        var(--window-color2) 6%,
        var(--window-color2) 9%
      );
  }
  
  .bb3 {
    width: 10%;
    height: 55%;
    background: repeating-linear-gradient(
        90deg,
        var(--building-color3),
        var(--building-color3),
        var(--window-color3) 15%
      );
  }
  
  .bb4 {
    width: 11%;
    height: 58%;
  }
  
  .bb4a {
    width: 3%;
    height: 10%;
    background-color: var(--building-color4);
  }
  
  .bb4b {
    width: 80%;
    height: 5%;
    background-color: var(--building-color4);
  }
    
  .bb4c {
    width: 100%;
    height: 85%;
    background-color: var(--building-color4);
  }
  
  .bb4-window {
    width: 18%;
    height: 90%;
    background-color: var(--window-color4);
  }
  
  /* FOREGROUND BUILDINGS - "fb" stands for "foreground building" */
  .fb1 {
    width: 10%;
    height: 60%;
  }
  
  .fb1a {
    border-bottom: 7vh solid var(--building-color4);
    border-left: 2vw solid transparent;
    border-right: 2vw solid transparent;
  }
  
  .fb1b {
    width: 60%;
    height: 10%;
    background-color: var(--building-color4);
  }
    
  .fb1c {
    width: 100%;
    height: 80%;
    background: repeating-linear-gradient(
        90deg,
        var(--building-color4),
        var(--building-color4) 10%,
        transparent 10%,
        transparent 15%
      ),
      repeating-linear-gradient(
        var(--building-color4),
        var(--building-color4) 10%,
        var(--window-color4) 10%,
        var(--window-color4) 90%
      );
  }
  
  .fb2 {
    width: 10%;
    height: 40%;
  }
  
  .fb2a {
    width: 100%;
    border-bottom: 10vh solid var(--building-color3);
    border-left: 1vw solid transparent;
    border-right: 1vw solid transparent;
  }
  
  .fb2b {
    width: 100%;
    height: 75%;
    background-color: var(--building-color3);
  }
  
  .fb2-window {
    width: 22%;
    height: 100%;
    background-color: var(--window-color3);
  }
  
  .fb3 {
    width: 10%;
    height: 35%;
  }
    
  .fb3a {
    width: 80%;
    height: 15%;
    background-color: var(--building-color1);
  }
    
  .fb3b {
    width: 100%;
    height: 35%;
    background-color: var(--building-color1);
  }
  
  .fb3-window {
    width: 25%;
    height: 80%;
    background-color: var(--window-color1);
  }
  
  .fb4 {
    width: 8%;
    height: 45%;
    position: relative;
    left: 10%;
  }
  
  .fb4a {
    border-top: 5vh solid transparent;
    border-left: 8vw solid var(--building-color1);
  }
  
  .fb4b {
    width: 100%;
    height: 89%;
    background-color: var(--building-color1);
    display: flex;
    flex-wrap: wrap;
  }
  
  .fb4-window {
    width: 30%;
    height: 10%;
    border-radius: 50%;
    background-color: var(--window-color1);
    margin: 10%;
  }
  
  .fb5 {
    width: 10%;
    height: 33%;
    position: relative;
    right: 10%;
    background: repeating-linear-gradient(
        var(--building-color2),
        var(--building-color2) 5%,
        transparent 5%,
        transparent 10%
      ),
      repeating-linear-gradient(
        90deg,
        var(--building-color2),
        var(--building-color2) 12%,
        var(--window-color2) 12%,
        var(--window-color2) 44%
      );
  }
  
  .fb6 {
    width: 9%;
    height: 38%;
    background: repeating-linear-gradient(
        90deg,
        var(--building-color3),
        var(--building-color3) 10%,
        transparent 10%,
        transparent 30%
      ),
      repeating-linear-gradient(
        var(--building-color3),
        var(--building-color3) 10%,
        var(--window-color3) 10%,
        var(--window-color3) 30%
      );
  }
  
  @media (max-width: 1000px) {
    :root {
      --building-color1: #000;
      --building-color2: #000;
      --building-color3: #000;
      --building-color4: #000;
    }
    .sky {
      background: radial-gradient(
          closest-corner circle at 15% 15%,
          #ccc,
          #ccc 20%,
          #445 21%,
          #223 100%
        );
    }
  }