Address Copilot review: a11y icons, footer list reset, back-to-top, link

- Mark decorative Font Awesome icons aria-hidden and add a space
  before adjacent label text (nav/hero/footer sponsor buttons,
  section headings, back-to-top arrow)
- Reset margin/padding on .footer-col ul to avoid inconsistent
  browser default indentation
- Guard back-to-top.js "at bottom" detection so it doesn't
  incorrectly show the button on short, non-scrollable pages
- Drop the bare trailing "#" from the Pillow 9.0.0 release notes link

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: aclark4life

assets/css/pillow.css

@@ -641,6 +641,8 @@ section {
     list-style: none;
     display: grid;
     gap: .6rem;
+    margin: 0;
+    padding: 0;
 }
 
 .footer-col a,

assets/js/back-to-top.js

@@ -9,7 +9,9 @@
 
     function update() {
         var scrollY = window.scrollY || window.pageYOffset;
-        var atBottom = window.innerHeight + scrollY >= document.documentElement.scrollHeight - 4;
+        var pageHeight = document.documentElement.scrollHeight;
+        var isScrollable = pageHeight > window.innerHeight;
+        var atBottom = isScrollable && window.innerHeight + scrollY >= pageHeight - 4;
         button.classList.toggle("is-visible", scrollY > SHOW_AFTER_PX || atBottom);
         ticking = false;
     }

index.html

@@ -39,11 +39,11 @@
                         <a href="#history">History</a>
                     </nav>
                     <a class="btn btn-sponsor btn-sm" href="#sponsor">
-                        <i class="fas fa-heart"></i>Sponsor</a>
+                        <i class="fas fa-heart" aria-hidden="true"></i> Sponsor</a>
                     <a class="icon-link" target="_blank" rel="noopener noreferrer" href="https://github.com/python-pillow/Pillow" aria-label="GitHub">
-                        <i class="fab fa-github"></i></a>
+                        <i class="fab fa-github" aria-hidden="true"></i></a>
                     <a class="icon-link" target="_blank" href="https://fosstodon.org/@pillow" rel="me noopener noreferrer" aria-label="Mastodon">
-                        <i class="fab fa-mastodon"></i></a>
+                        <i class="fab fa-mastodon" aria-hidden="true"></i></a>
                 </div>
             </div>
         </header>
@@ -62,7 +62,7 @@ <h1>Pillow</h1>
                             <a class="btn btn-primary btn-lg" target="_blank" rel="noopener noreferrer" href="https://pypi.org/project/pillow/">Download from PyPI</a>
                             <a class="btn btn-outline btn-lg" target="_blank" rel="noopener noreferrer" href="https://pillow.readthedocs.io/">Read the docs</a>
                             <a class="btn btn-sponsor btn-lg" href="#sponsor">
-                                <i class="fas fa-heart"></i>Sponsor</a>
+                                <i class="fas fa-heart" aria-hidden="true"></i> Sponsor</a>
                         </div>
                     </div>
                     <div class="hero-art">
@@ -114,7 +114,7 @@ <h3>Source Code</h3>
             <section id="sponsor" class="sponsor">
                 <div class="wrap">
                     <div class="section-head center">
-                        <h2><i class="fas fa-heart"></i> Support Pillow's Future</h2>
+                        <h2><i class="fas fa-heart" aria-hidden="true"></i> Support Pillow's Future</h2>
                         <p>
                             Pillow is free, open source software maintained by volunteers who review pull requests,
                             fix bugs, write documentation, and ship regular releases &mdash; all in their spare time.
@@ -124,13 +124,13 @@ <h2><i class="fas fa-heart"></i> Support Pillow's Future</h2>
                         </p>
                     </div>
                     <div class="sponsor-grid">
-                        <div class="sponsor-chip"><i class="fas fa-shield-halved"></i>Fund security fixes and long-term maintenance</div>
-                        <div class="sponsor-chip"><i class="fas fa-code-branch"></i>Prioritize reviewing PRs and issues</div>
-                        <div class="sponsor-chip"><i class="fas fa-users"></i>Sustain the maintainers who ship Pillow</div>
+                        <div class="sponsor-chip"><i class="fas fa-shield-halved" aria-hidden="true"></i> Fund security fixes and long-term maintenance</div>
+                        <div class="sponsor-chip"><i class="fas fa-code-branch" aria-hidden="true"></i> Prioritize reviewing PRs and issues</div>
+                        <div class="sponsor-chip"><i class="fas fa-users" aria-hidden="true"></i> Sustain the maintainers who ship Pillow</div>
                     </div>
                     <div style="text-align: center;">
                         <a class="btn btn-sponsor-light btn-lg" target="_blank" rel="noopener noreferrer" href="https://github.com/sponsors/python-pillow">
-                            <i class="fas fa-heart"></i>Become a GitHub Sponsor</a>
+                            <i class="fas fa-heart" aria-hidden="true"></i> Become a GitHub Sponsor</a>
                     </div>
                 </div>
             </section>
@@ -248,7 +248,7 @@ <h2>From PIL to <span class="highlight">Pillow</span></h2>
             <div class="memory">
                 <a target="_blank" rel="noopener noreferrer" href="https://pillow.readthedocs.io/en/stable/releasenotes/9.0.0.html#fredrik-lundh">In memory of Fredrik Lundh</a>
                 <p class="memory-note">
-                    <a target="_blank" rel="noopener noreferrer" href="https://pillow.readthedocs.io/en/stable/releasenotes/9.0.0.html#">Pillow 9.0.0</a> was dedicated to the memory of Fredrik Lundh, aka Effbot, who died in
+                    <a target="_blank" rel="noopener noreferrer" href="https://pillow.readthedocs.io/en/stable/releasenotes/9.0.0.html">Pillow 9.0.0</a> was dedicated to the memory of Fredrik Lundh, aka Effbot, who died in
                     November 2021. Fredrik created PIL in 1995 and was instrumental in the
                     <a target="_blank" rel="noopener noreferrer" href="https://mail.python.org/archives/list/python-dev@python.org/thread/36Q5QBILL3QIFIA3KHNGFBNJQKXKN7SD/">early success of Python</a>.
                 </p>
@@ -267,9 +267,9 @@ <h2>From PIL to <span class="highlight">Pillow</span></h2>
                     <p>The Python Imaging Library, maintained by a community of volunteers since 2010.</p>
                     <div class="footer-social">
                         <a class="icon-link" target="_blank" rel="noopener noreferrer" href="https://github.com/python-pillow/Pillow" aria-label="GitHub">
-                            <i class="fab fa-github"></i></a>
+                            <i class="fab fa-github" aria-hidden="true"></i></a>
                         <a class="icon-link" target="_blank" href="https://fosstodon.org/@pillow" rel="me noopener noreferrer" aria-label="Mastodon">
-                            <i class="fab fa-mastodon"></i></a>
+                            <i class="fab fa-mastodon" aria-hidden="true"></i></a>
                     </div>
                 </div>
                 <div class="footer-col">
@@ -291,7 +291,7 @@ <h4>Community</h4>
                     </ul>
                 </div>
                 <div class="footer-col footer-sponsor">
-                    <h4><i class="fas fa-heart"></i> Support Pillow</h4>
+                    <h4><i class="fas fa-heart" aria-hidden="true"></i> Support Pillow</h4>
                     <p>Pillow is maintained by volunteers. Sponsorship funds security fixes, reviews and new features.</p>
                     <a class="btn btn-sponsor btn-sm" target="_blank" rel="noopener noreferrer" href="https://github.com/sponsors/python-pillow">Become a Sponsor</a>
                 </div>
@@ -307,7 +307,7 @@ <h4><i class="fas fa-heart"></i> Support Pillow</h4>
         </footer>
 
         <a class="back-to-top" href="#top" aria-label="Back to top">
-            <i class="fas fa-arrow-up"></i>
+            <i class="fas fa-arrow-up" aria-hidden="true"></i>
         </a>
 
         <script src="assets/js/back-to-top.js"></script>