feat: add footer

Co-authored-by: Copilot <copilot@github.com>

footer.css

@@ -0,0 +1,106 @@
+@font-face {
+    font-family: 'Splatoon1';
+    src: url('/splatoon1.otf') format('opentype');
+}
+@font-face {
+    font-family: 'RegularFont';
+    src: url('/regular.otf') format('opentype');
+}
+
+.site-footer {
+    width: 100%;
+    background-color: #000;
+    color: white;
+    margin-top: 50px;
+    font-family: 'RegularFont', sans-serif;
+}
+
+.footer-wave-container {
+    line-height: 0;
+    width: 100%;
+}
+
+.footer-wave {
+    width: 100%;
+    height: auto;
+}
+
+.footer-grid {
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+    max-width: 1200px;
+    margin: 0 auto;
+    padding: 20px 40px;
+}
+
+.footer-left {
+    display: flex;
+    align-items: center; 
+    gap: 20px;
+    transform: translateY(-15px);
+}
+
+.logo-footer {
+    width: 200px;
+    height: auto;
+    display: block;
+    
+}
+
+.tagline {
+    font-family: 'Splatoon1', sans-serif;
+    font-size: 1.4rem;
+    color: #efefef;
+    white-space: nowrap;
+}
+
+.footer-right {
+    display: flex;
+    flex-direction: column;
+    align-items: flex-end;
+    gap: 10px;
+}
+
+.logo-row {
+    display: flex;
+    align-items: center;
+    gap: 15px;
+}
+
+.icon-logo {
+    height: 24px;
+    width: auto;
+}
+
+.footer-nav {
+    display: flex;
+    gap: 15px;
+}
+
+.footer-nav a {
+    color: #999;
+    text-decoration: none;
+    font-size: 0.9rem;
+}
+
+.footer-nav a:hover {
+    color: #fff;
+    text-decoration: underline;
+}
+
+/* mobile net */
+@media (max-width: 768px) {
+    .footer-grid {
+        flex-direction: column;
+        text-align: center;
+        gap: 30px;
+    }
+    .footer-left {
+        flex-direction: column;
+        gap: 10px;
+    }
+    .footer-right {
+        align-items: center;
+    }
+}

footer.html

@@ -0,0 +1,32 @@
+<footer class="site-footer">
+    <div class="footer-wave-container">
+        <img src="/assets/en/svg/ui/bg_header_wave-59d556a181d6146620e75ca3adea5b61bd175820334270a7828974276cb6765f.svg" class="footer-wave" alt="" aria-hidden="true" />
+    </div>
+
+    <div class="footer-grid">
+        <div class="footer-left">
+            <img src="/assets/en/ui/fullimg_splatnetlogo.png" class="logo-footer" alt="SplatNet Logo" />
+            <span class="tagline">Stay Fresh!</span>
+        </div>
+
+        <div class="footer-right">
+            <div class="logo-row">
+                <span class="partner-label">Git</span>
+                <a href="https://git.crafterpika.cc/kittentm/splatnet">
+                    <img src="https://git.crafterpika.cc/assets/img/logo.svg" class="icon-logo" alt="Forgejo Logo" />
+                </a>
+                <a href="https://github.com/KittenTM/splatnet">
+                    <img src="https://github.githubassets.com/favicons/favicon.svg" class="icon-logo" alt="GitHub Logo" />
+                </a>
+            </div>
+            
+            <nav class="footer-nav">
+                <a href="https://git.crafterpika.cc/kittentm/splatnet/src/branch/main">Source Code</a>
+                <a href="https://git.crafterpika.cc/kittentm/splatnet/issues">Issues</a>
+                <a href="https://git.crafterpika.cc/kittentm/splatnet/pulls">Contribute</a>
+                <a href="https://git.crafterpika.cc/kittentm/splatnet/activity">Contributors</a>
+            </nav>
+        </div>
+    </div>
+</footer>
+<link rel="stylesheet" href="/footer.css" />