JSFiddle - React, Tailwind, and code Playground

HTML

<p>
                                   <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>
</p>
<p>
                                <button class="knopka1" >Б</button>
                                 <button class="knopka1" >Б</button>
                                 <button class="knopka1" >Б</button>
                                  <button class="knopka1" >Б</button>
                                <button class="knopka1" >Б</button>
</p>

CSS

.knopka{ width:50px; height:50px; margin: 0 10px 10px 0; float:left; }
.knopka1{ width:50px; height:50px; margin: 0 10px 10px 0; float:left; }