<div class="tree">
<div class="tree-1"></div>
<div class="tree-2"></div>
<div class="tree-3"></div>
<div class="tree-4"></div>
<div class="tree-5"></div>
<div class="tree-6"></div>
<div class="tree-7"></div>
<div class="tree-8"></div>
<div class="tree-5"></div>
<div class="tree-6"></div>
<div class="tree-7"></div>
<div class="tree-8"></div>
<div class="_tree"></div>
</div>
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.tree {
[class^=tree] {
height:12px;
background:#0F8A5F;
margin:0 auto;
}
[class^=tree]:nth-child(2n) {
background:#34A65F;
}
.tree-1 {
width:30px;
}
.tree-2 {
width:50px;
}
.tree-3 {
width:70px;
}
.tree-4 {
width:90px;
}
.tree-5 {
width:110px;
}
.tree-6 {
width:130px;
}
.tree-7 {
width:150px;
}
.tree-8 {
width:170px;
}
._tree {
width:20px;
height:55px;
background:#8a3b16;
margin:0 auto;
}
}