JSFiddle - React, Tailwind, and code Playground

HTML

<div class="box-slider">
        <h2>Como aparece no Chrome</h2>
</div>

<div class="box-slider-errado">
        <h2>Como aparece no IE9</h2>
</div>

CSS

.box-slider h2, .box-slider-errado h2{
    font-size: 23px;
    background-color: #084867;
    color: #fff;
    padding: 5px 10px 2px;
    line-height: 31px;
}
.box-slider h2{
    display: initial;
}
.box-slider-errado h2{
    display: block;    
}