demo/vertical-horizontal-center/horizontal/1-text-align.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        .text-center {
            text-align: center;
        }
        .red {
            display: inline-block;
            background-color: red;
            width: 100px;
            height: 20px;
        }
    </style>
</head>
<body>
    <div class="text-center">
        <span>horizontal</span>
    </div>
    <div class="text-center">
        <div class="red"></div>
    </div>
</body>
</html>