JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>
    <head>
        <meta name="viewport" content="width=device-width, initial-scale=1">
    </head>
    <body>
        <h1>max-width issue</h1>
        <div class="column column639">
            <h2>Column 1</h2>
        </div>
          
        <div class="column column640">
            <h2>Column 2</h2>
        </div>
    </body>
</html>

CSS

.column {
			width: 100%;
			background-color: cyan;
		}

		@media screen and (max-width: 639px) {
		  .column639 {
			visibility: hidden;
		  }
		}

		@media screen and (max-width: 640px) {
		  .column640 {
			visibility: hidden;
		  }
		}