JSFiddle - React, Tailwind, and code Playground
HTML
<span class="plus">–</span>
<span class="plus">+</span>
CSS
.plus {
border: solid 1px black;
border-radius: 50%;
width: 14px;
height: 14px;
display: inline-block;
text-align: center;
vertical-align: middle;
line-height: 14px;
font-size: 14px;
font-weight: bold;
cursor: pointer;
}