下面代码放入主题自定义CSS

/*底部可爱底线提示*/.lastpagenotice_noticewrap{color:hsla(0, 2.1%, 18.8%, 0.6);}.lastpagenotice_noticewrap img{height:73px; width:88px; margin:0 auto}.lastpagenotice_noticewrap .lastpagenotice_text{display:block; position:absolute; font-size:15px; line-height:20px; top:50%; -webkit-transform:translateY(-50%); -ms-transform:translateY(-50%); transform:translateY(-50%); left:-webkit-calc(50% + 60px); left:calc(50% + 60px)}.lastpagenotice_noticewrap .lastpagenotice_line{width:100%; height:1px; background-color:hsla(0,0%,100%,.05); position:absolute; bottom:0}.app_normal{text-align:center; position:relative}

下面代码放入 子比根目录文件footer.php内 footer标签前面

<!--底部可爱底线提示-->
<div class="app_normal window" style="padding-top:" data-reactroot=""><div class="common_container lastpagenotice_noticewrap"><img src="https://www.mduge.com/lan.png" data-spm-anchor-id="a2ha1.14919748_WEBHOME_GRAY.0.i1"><div class="lastpagenotice_text"  style="color:#6699FF;font-weight:bold;">我也是有底线哒~</div><div class="lastpagenotice_line"></div></div></div>