space before/after <div>

by emmaJsFiddle

HTML

<html>
     <body>
        <section> <div class="a"></div><div class="b"></div></section>
    </body>
</html>

CSS

section { height: 120px; background: gray; width: 100px; font-size: 100px;}
div { display: inline-block; }
.a { background: red ; height: 50px; width: 20px}
.b { background: cyan; height: 50px; width: 20px}

JavaScript

let x;