JSFiddle - React, Tailwind, and code Playground

HTML

<div id="knopki">
                                   <button class="knopka" >А</button>
                                <button class="knopka" >А</button>
                        <button class="knopka" >А</button>
                         <button class="knopka" >А</button>
                         <button class="knopka" >А</button>
    <button class="knopka" >B</button>
                                <button class="knopka" >B</button>
                        <button class="knopka" >B</button>
                         <button class="knopka" >B</button>
                         <button class="knopka" >B</button>
</div>

CSS

.knopka{ width:50px; height:50px; margin: 0 10px 10px 0; float:left; }
#knopki{width:300px}