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diff --git a/public/mutual-links/yank-nvim.png b/public/mutual-links/yank-nvim.png
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diff --git a/src/components/Chat.tsx b/src/components/Chat.tsx
index 990b74d..683cc65 100644
--- a/src/components/Chat.tsx
+++ b/src/components/Chat.tsx
@@ -81,8 +81,17 @@ export default function Chat() {
 
     return (
         <RecoilRoot>
-            <div className={`w-1/2 absolute flex items-center p-4 text-sm border border-gray-300 rounded-lg bg-gray-800 text-gray-300 border-gray-600${alert === "" ? ` hidden` : ``}`} role="alert">
-                <svg className="flex-shrink-0 inline w-4 h-4 me-3" aria-hidden="true" xmlns="http://www.w3.org/2000/svg" fill="currentColor" viewBox="0 0 20 20">
+            <div
+                className={`w-1/2 absolute flex items-center p-4 text-sm border border-gray-300 rounded-lg bg-gray-800 text-gray-300 border-gray-600${alert === "" ? ` hidden` : ``}`}
+                role="alert"
+            >
+                <svg
+                    className="flex-shrink-0 inline w-4 h-4 me-3"
+                    aria-hidden="true"
+                    xmlns="http://www.w3.org/2000/svg"
+                    fill="currentColor"
+                    viewBox="0 0 20 20"
+                >
                     <path d="M10 .5a9.5 9.5 0 1 0 9.5 9.5A9.51 9.51 0 0 0 10 .5ZM9.5 4a1.5 1.5 0 1 1 0 3 1.5 1.5 0 0 1 0-3ZM12 15H8a1 1 0 0 1 0-2h1v-3H8a1 1 0 0 1 0-2h2a1 1 0 0 1 1 1v4h1a1 1 0 0 1 0 2Z"/>
                 </svg>
                 <div>
@@ -95,18 +104,35 @@ export default function Chat() {
                         名前{" "}
                         <span className="text-orange-400">*</span>
                     </label>
-                    <input type="text" id="name" className="w-full block p-4 border rounded-lg text-base dark:bg-neutral-900 border-gray-600 dark:placeholder-gray-400 dark:text-white focus:ring-blue-500 focus:border-blue-500" value={name} onChange={updateName} placeholder="Hatsune Mike" />
+                    <input
+                        type="text"
+                        id="name"
+                        className="w-full block p-4 border rounded-lg text-base dark:bg-neutral-900 border-gray-600 dark:placeholder-gray-400 dark:text-white focus:ring-blue-500 focus:border-blue-500"
+                        value={name}
+                        onChange={updateName}
+                        placeholder="Hatsune Mike"
+                        aria-label="名前"
+                    />
                 </div>
                 <div className="mb-5">
                     <label className="block mb-2 text-sm font-medium dark:text-white">
                         本文{" "}
                         <span className="text-orange-400">*</span>
                     </label>
-                    <textarea id="body" rows={4} className="font-serif text-2xl w-full block p-2.5 rounded-lg border dark:bg-neutral-900 border-gray-600 dark:placeholder-gray-400 dark:text-white focus:ring-blue-500 focus:border-blue-500" placeholder="言い残したいことは？" value={body} onChange={updateBody}></textarea>
+                    <textarea
+                        aria-label="チャットの本文"
+                        id="body"
+                        rows={4}
+                        className="font-serif text-2xl w-full block p-2.5 rounded-lg border dark:bg-neutral-900 border-gray-600 dark:placeholder-gray-400 dark:text-white focus:ring-blue-500 focus:border-blue-500" 
+                        placeholder="言い残したいことは？"
+                        value={body}
+                        onChange={updateBody}
+                    ></textarea>
                 </div>
                 <button
                     onClick={submit}
                     type="button"
+                    aria-label="チャットを送信"
                     className={`w-full text-xl dark:text-white hover:text-white focus:ring-4 focus:outline-none font-medium rounded-lg text-sm px-5 py-2.5 text-center border border-2 border-blue-600 hover:bg-blue-700 focus:ring-blue-800${ name === "" || body === "" ? " opacity-20" : ""}`}
                     disabled={name === "" || body === ""}
                 >
diff --git a/src/components/Footer.tsx b/src/components/Footer.tsx
index 0c8e972..38ddddf 100644
--- a/src/components/Footer.tsx
+++ b/src/components/Footer.tsx
@@ -1,9 +1,9 @@
 export default function Footer() {
     return (
         <div className="text-center text-gray-500 mb-5">
-            <img src="./banner_new.png" className="h-12 inline" />
-            <img src="./busy_banner.webp" className="h-12 inline" />
-            <img src="https://moe-counter-cf.yude.workers.dev/yude.jp:home" className="h-20 mx-auto" />
+            <img alt="yude.jp banner" src="./banner_new.png" className="h-12 inline" />
+            <img alt="happybusy" src="./busy_banner.webp" className="h-12 inline" />
+            <img alt="Page view counter" src="https://moe-counter-cf.yude.workers.dev/yude.jp:home" className="h-20 mx-auto" />
             <p className="mt-5">
                 <a href="https://github.com/yudejp/yude.jp">
                     &copy; 2024 yude
diff --git a/src/components/Links.tsx b/src/components/Links.tsx
index 5b6a954..f79bab5 100644
--- a/src/components/Links.tsx
+++ b/src/components/Links.tsx
@@ -57,7 +57,7 @@ export default function Links() {
                     </div>
                     <div className="w-24 h-16">
                         <a href="https://scrapbox.io/yude">
-                            <img src="./logo/scrapbox.svg" className="w-24 h-12 grayscale" />
+                            <img alt="Scrapbox" src="./logo/scrapbox.svg" className="w-24 h-12 grayscale" />
                             <span className="block dark:text-gray-400 text-center">
                                 Scrapbox
                             </span>
@@ -65,7 +65,7 @@ export default function Links() {
                     </div>
                     <div className="w-24 h-16">
                         <a href="https://zenn.dev/yude">
-                            <img src="./logo/zenn.svg" className="w-24 h-12 text-center dark:invert" />
+                            <img alt="Zenn" src="./logo/zenn.svg" className="w-24 h-12 text-center dark:invert" />
                             <span className="block dark:text-gray-400 text-center">
                                 Zenn
                             </span>
@@ -73,7 +73,7 @@ export default function Links() {
                     </div>
                     <div className="w-24 h-16">
                         <a href="https://yudejp.hatenablog.jp">
-                            <img src="./logo/hatenablog.svg" className="w-24 h-12 text-center dark:invert" />
+                            <img alt="はてなブログ" src="./logo/hatenablog.svg" className="w-24 h-12 text-center dark:invert" />
                             <span className="block dark:text-gray-400">
                                 はてなブログ
                             </span>
@@ -81,7 +81,7 @@ export default function Links() {
                     </div>
                     <div className="w-24 h-16">
                         <a href="https://sizu.me/yude">
-                            <img src="./logo/sizume.svg" className="w-24 h-12 text-center dark:invert" />
+                            <img alt="しずかなインターネット" src="./logo/sizume.svg" className="w-24 h-12 text-center dark:invert" />
                             <span className="block dark:text-gray-400 text-center">
                                 しずかなインターネット
                             </span>
@@ -121,7 +121,7 @@ export default function Links() {
                     </div>
                     <div className="w-24 h-16">
                         <a href="https://annict.com/yude">
-                            <img src="./logo/annict.png" className="w-12 h-12 ml-6 grayscale" />
+                            <img alt="Annict" src="./logo/annict.png" className="w-12 h-12 ml-6 grayscale" />
                             <span className="block dark:text-gray-400 text-center">
                                 Annict
                             </span>
@@ -129,7 +129,7 @@ export default function Links() {
                     </div>
                     <div className="w-24 h-16">
                         <a href="https://vrcprofile.com/p/yude">
-                            <img src="./logo/vrchat.png" className="w-12 ml-6 mt-5" />
+                            <img alt="VRChat" src="./logo/vrchat.png" className="w-12 ml-6 mt-5" />
                             <span className="block dark:text-gray-400 text-center mt-2">
                                 VRChat
                             </span>
diff --git a/src/components/Theme.tsx b/src/components/Theme.tsx
index 2eb88ed..fcfeead 100644
--- a/src/components/Theme.tsx
+++ b/src/components/Theme.tsx
@@ -39,6 +39,7 @@ export const ThemeSwitcher = () => {
             type="button"
             className="btn btn-secondary"
             onClick={toggleTheme}
+            aria-label="テーマの切り替え"
           >
             {theme === "light" ? (
               <FontAwesomeIcon icon={faMoon} />
diff --git a/src/index.css b/src/index.css
index 85aa649..84ad34f 100644
--- a/src/index.css
+++ b/src/index.css
@@ -4,7 +4,7 @@
 
 @layer base {
   body {
-    @apply bg-zinc-200;
+    @apply bg-zinc-100;
     @apply dark:bg-neutral-900;
   }
 }
diff --git a/tailwind.config.js b/tailwind.config.js
index 2a11ef4..777bd34 100644
--- a/tailwind.config.js
+++ b/tailwind.config.js
@@ -6,7 +6,17 @@ export default {
     "./src/**/*.{js,ts,jsx,tsx}",
   ],
   theme: {
-    extend: {},
+    extend: {
+      animation: {
+        marquee: 'marquee 30s linear infinite'
+      },
+      keyframes: {
+        marquee: {
+          '0%': { transform: 'translateX(100%)' },
+          '100%': { transform: 'translateX(-160%)' }
+        }
+      }
+    },
   },
   plugins: [
     require('@tailwindcss/typography'),
diff --git a/vite.config.ts b/vite.config.ts
index d0e1f3d..d642626 100644
--- a/vite.config.ts
+++ b/vite.config.ts
@@ -6,6 +6,7 @@ import react from '@vitejs/plugin-react-swc'
 export default defineConfig({
   plugins: [react()],
   build: {
+    sourcemap: true,
     rollupOptions: {
       input: {
         main: resolve(__dirname, 'index.html'),