JSFiddle - React, Tailwind, and code Playground

HTML

Will work..

<div class="wrapper">    
     <div class="aside_left">Left content...</div>
     <div class="main_page">Main content...</div>
</div> 

Wont work..

<div class="wrapper">    
     <div class="main_page">Main content...</div>
     <div class="aside_left">Left content...</div>
</div>

CSS

.wrapper{
    margin:20px 0;
}
.wrapper .aside_left:nth-of-type(odd){
    background:red;
}