: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{
    height: 100%;
    width: 100%;
    position: absolute;
    top: 0;
    display: flex;
    justify-content: space-evenly;
    align-items: flex-end;
}
.sky{
    background: radial-gradient(
        circle closest-corner at 15% 15%,
        #ffcf33 0%,
        #ffcf33 20%,
        #ffff66 21%,
        #bbeeff 100%
    );
}
.building-wrap{
    
    display: flex;
    flex-direction: column;
    align-items: center;
}
.window-wrap{
    display: flex;
    align-items: center;
    justify-content: space-evenly;
}
/*BACKGROUND BUILDINGS - "bb" stands for "background building"*/
.bb1-window{
    height: 10%;
    background: linear-gradient(
        var(--building-color1),
        var(--window-color1)
      );
}
.bb1{
    height: 70%;
    width: 10%;
}
.bb1a{
    width: 70%;
}
.bb1b{
    width: 80%;
}
.bb1c{
    width: 90%;
}
.bb1d{
    height: 70%;
    width: 100%;
    background: linear-gradient(
        var(--building-color1) 50%,
        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) 0%,
        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%;
}
.bb4-window{
    width: 18%;
    height: 90%;
    background-color: var(--window-color4);
}
.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);
}
/*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%;
}
.fb2-window{
    width: 22%;
    height: 100%;
    background-color: var(--window-color3);
}
.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);
}
.fb3{
    width: 10%;
    height: 35%;
}
.fb3-window{
    width: 25%;
    height: 80%;
    background-color: var(--window-color1);
}
.fb3a{
    width: 80%;
    height: 15%;
    background-color: var(--building-color1);
}
.fb3b{
    width: 100%;
    height: 35%;
    background-color: var(--building-color1);
}
.fb4{
    width: 8%;
    height: 45%;
    position: relative;
    left: 10%;
}
.fb4-window{
    width: 30%;
    height: 10%;
    border-radius: 50%;
    margin: 10%;
    background-color: var(--window-color1);
}
.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;
}
.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;
        --window-color1: #777;
        --window-color2: #777;
        --window-color3: #777;
        --window-color4: #777;
    }

    .sky {
        background: radial-gradient(
      closest-corner circle at 15% 15%,
      #ccc,
      #ccc 20%,
      #445 21%,
      #223 100%
        );
    }
}