#toolbox .item {
    width:100px;    
    background: aqua;
    margin: 10px 0;
    padding: 10px;
    text-align: center;
    border-radius: 10px;
    cursor: pointer;
    z-index: 2;
    position: relative; 
}

#workspace {
    position: relative;
    font-size: smaller;
    padding: 20px;
    height: 600px;
    border: 1px solid gray;
    background: #fff;
    background-image: linear-gradient(#bab5b54d 1px, transparent 0),
    linear-gradient(90deg, #bab5b54d 1px, transparent 0),
    linear-gradient(#bab5b54d 1px, transparent 0),
    linear-gradient(90deg, #bab5b54d 1px, transparent 0);
    background-size: 15px 15px, 15px 15px, 75px 75px, 75px 75px;
}

#workspace .rectangle-size {
    position: absolute;
    text-align: center;
    line-height: 40px;
    height: 40px;
    width: 100px;
    border: 2px solid #000;
    border-radius: 5px;
}