<!doctype html>
<html>
<head>
    <meta charset="utf-8">
    <title></title>
    <style type="text/css">
        /* Example from
           https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Background_and_Borders/Using_CSS_multiple_backgrounds
           (Public domain)

           bubbles.png is from the above MDN page, by Mozilla contributors,
           licensed under CC-BY-SA 2.5

           Rust logo from https://www.rust-lang.org/logos/rust-logo-256x256.png,
           licensed as CC-BY-SA 4.0, own