JSFiddle - React, Tailwind, and code Playground

HTML

<div id="wrapper">
    <div id="space">#space</div>
    <div id="b730"  class="box">30</div>
    <div id="b230"  class="box">230</div>
    <div id="b390"  class="box">90</div>    
    <div id="b1100" class="box">1100</div>
</div>

CSS

#wrapper {
    position: absolute ;
    top: 10px ;
    left: 10px ;
    width: 300px ;
    height: 350px ;
    background-color: grey ;
}

#wrapper div {
    margin: 1px ;
}

#space {
    width: 100px ;
    height: 99px ;
}

#space:hover {
    background-color: lightgrey ;
}

.box {
    width: 100px ;
    background-color: lightgreen ;
}

#b1100 {
    height: 110px ;
}

#b390{
    height: 39px ;
}

#b230 {
    height: 23px ;
}

#b730 {
    height: 73px ;
}