console 命令行工具 X clear

console

<div class="outside">
    <div class="inside">hhh</div>
</div>

div.outside {
    background-color: skyblue;
    width: 300px;
    height: 200px;
}

div.inside {
    /* 垂直居中 */
    line-height: 200px;

    /* 水平居中 */
    text-align: center;
}