.square {
    width: 600px;
    height: 600px;
    float: left;
    display: inline-block;
    background-image: url(https://img.freepik.com/premium-photo/concrete-paper-texture-background_534308-153.jpg)
}

.square2 {
    width:150px;
    height: 150px;
    border-style: none solid solid solid;
    border-color: black;
    border-width: 15px;
    position: absolute;
    align-content: center;
    left: 210px;
}

#container2 { 
    position: absolute;
    width: 210px;
    left: 195px;
    top: 210px;
}

#container {
    width: 600px;
    height: 900px;
    margin: 0 auto;
    position: relative;
}

#gray {
    background-color: lightgray;
}

#red {
    background-color: red;
}

#gold { 
background-color:#dfccac;
}

.rectangle2 {
    width: 600px;
    height: 150px;
    border-top-style: solid;
    border-top-color: black;
    border-top-width: 15px;
    float: left;
}

.rectangle {
    width: 600px;
    height: 150px;
    float: left;
}

.initialrectangle {
    height: 180px; 
    width: 40px;
    border-style: solid;
    border-color: black;
    border-width: 10px;
    float: left;
}

.initialrectangle2 {
    height: 180px; 
    width: 40px;
    border-style: solid;
    border-color: black;
    border-width: 10px;
    border-left-style: none;
    float: left;
}