usr/themes/Cuckoo/includes/header.php，body标签里。
js花瓣动画：
<canvas width="1440" height="338" id="js-background"></canvas>
更多css：#js-background{position: fixed;inset: 0;pointer-events: none;}
<script src="https://shiraikuroko.com/usr/themes/Cuckoo/assets/js/createjs.min.js"></script>
<script src="https://shiraikuroko.com/usr/themes/Cuckoo/assets/js/particlejs_gochiusa.js"></script>
<script src="https://shiraikuroko.com/usr/themes/Cuckoo/assets/js/petal.js"></script>
备用链接

<div class="background3"></div> <div id="wrapper"></div>
更多css：

body::before, body::after, body .background3{content:'';position:fixed;inset:0;z-index:0;pointer-events:none;}body::before{background:url(/usr/themes/Cuckoo/assets/images/0v0/01.png);opacity:.7;}body::after{background:url(/usr/themes/Cuckoo/assets/images/0v0/02.png);opacity:1;}body .background3{background:url(/usr/themes/Cuckoo/assets/images/0v0/03.png);opacity:.4;}

更多css：

#wrapper::before{left:0;transform:scale(-1, 1);}#wrapper::after{right:0;}#wrapper::before, #wrapper::after{content:"";position:fixed;background:url(https://gochiusa.com/bloom/core_sys/images/main/common/deco_side.svg) top / 100% auto;top:0;bottom:0;width:12%;max-width:160px;z-index:0;}

.footer{z-index: 1;}
usr/themes/Cuckoo/index.php
mdui-col-md-8标签里：<div id="side"></div>
更多css：

#side::before{left:1;}#side::after{right:8px;transform:scale(-1, 1);}#side::before, #side::after{content:"";position:absolute;top:0;bottom:0;width:17px;background:url(https://gochiusa.com/bloom/core_sys/images/main/common/deco_sidebar.svg) top center / contain;z-index:1;}