love/public/themes/simpleboot3/portal/demo.html

<extend name="public@base"/>
<block name="css">
    <link rel="stylesheet" href="__TMPL__/public/assets/css/userwall.css">
    <style>
    </style>
</block>
<block name="body">
    <van-nav-bar
            class="bg-pink"
            left-text="返回"
            left-arrow
            @click-left="onBack">
        <template #title>
            <span style="color:white;">标题</span>
        </template>
    </van-nav-bar>
</block>
<block name="script">
    <script>
        new Vue({
            el: '#app',
            data() {
                return {

                };
            },
            methods: {
                onBack() {
                    history.back();
                },
            },
        });
    </script>
</block>