css中如何让字体居中显示

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Text Centering</title>
    <style>
        .container {
            text-align: center;
        }
    </style>
</head>
<body>
    <div class="container">
        <span>This text is centered horizontally.</span>
    </div>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Text Centering</title>
    <style>
        .container {
            width: 200px;
            margin: 0 auto;
        }
    </style>
</head>
<body>
    <div class="container">
        This text is centered horizontally.
    </div>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Text Centering</title>
    <style>
        .container {
            display: flex;
            justify-content: center;
            align-items: center;
            height: 200px;
            border: 1px solid black;
        }
    </style>
</head>
<body>
    <div class="container">
        This text is centered both horizontally and vertically.
    </div>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Text Centering</title>
    <style>
        .container {
            display: grid;
            place-items: center;
            height: 200px;
            border: 1px solid black;
        }
    </style>
</head>
<body>
    <div class="container">
        This text is centered both horizontally and vertically.
    </div>
</body>
</html>