JSFiddle - React, Tailwind, and code Playground

HTML

<div id="center">
    
    <div id="left">prawy bardziej z lewej</div>
    <div id="right">prawy<div>
    
    
</div>

CSS

#center {
    border: 1px dashed #CAD;
    width: 420px;
    height: 100px;
    margin-left: auto;
    margin-right: auto;
    text-align: center;
}

#left {
    display: inline-block;
    border: 1px dashed #011;
    width: 100px;
    height: 70px;
    vertical-align: middle;
    margin-right: -2px; /* tutaj zmiany */
}

#right {
    display: inline-block;
    border: 1px solid #DAC;
    width: 100px;
    height: 70px;
    vertical-align: middle;
    margin-left: -2px; /* tutaj zmiany */
}