haoshengxin/api/views/site/myhtml.php

<?php
/* @var $this yii\web\View */
?>
<style>

    .container img{
        width: 100%;
        height: auto;
    }
    .title{
        margin-top: 1rem;
        font-size: 1.3rem;
        line-height: 1.5rem;
        color: #000;
        font-weight: bold;
        text-align: center;
    }
</style>
<div class="title">
    <?=$content->title?$content->title:''; ?>
</div>
    <?=$content->content?$content->content:'';?>