css字居中

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>水平居中示例</title>
    <style>
        .center-text {
            text-align: center;
        }
        .center-block {
            width: 200px;
            margin: 0 auto;
            background-color: #f0f0f0;
        }
    </style>
</head>
<body>
    <h1 class="center-text">水平居中的标题</h1>
    <div class="center-block">水平居中的块级元素</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>垂直居中示例</title>
    <style>
        .vertical-center {
            display: flex;
            align-items: center;
            height: 200px;
            background-color: #f0f0f0;
        }
    </style>
</head>
<body>
    <div class="vertical-center">垂直居中的文本</div>
</body>
</html>