diff --git a/package-lock.json b/package-lock.json
index f5cd435..ee81560 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "holodream-tools",
-  "version": "0.1.0",
+  "version": "1.0.1",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "holodream-tools",
-      "version": "0.1.0",
+      "version": "1.0.1",
       "engines": {
         "node": ">=22.12.0"
       },
diff --git a/package.json b/package.json
index c9af01c..3052d34 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "holodream-tools",
-  "version": "0.1.0",
+  "version": "1.0.1",
   "private": true,
   "type": "module",
   "engines": {
diff --git a/src/lib/components/UpdateNotice.svelte b/src/lib/components/UpdateNotice.svelte
new file mode 100644
index 0000000..0af195c
--- /dev/null
+++ b/src/lib/components/UpdateNotice.svelte
@@ -0,0 +1,152 @@
+<script lang="ts">
+  import { onMount } from 'svelte';
+  import packageInfo from '../../../package.json';
+
+  type ReleaseAsset = {
+    name: string;
+    browser_download_url: string;
+  };
+
+  type GitHubRelease = {
+    tag_name: string;
+    html_url: string;
+    draft: boolean;
+    prerelease: boolean;
+    assets: ReleaseAsset[];
+  };
+
+  type CachedRelease = {
+    checkedAt: number;
+    release: GitHubRelease;
+  };
+
+  const currentVersion = packageInfo.version;
+  const releaseApiUrl = 'https://api.github.com/repos/DD4SN/HolodoriCalc/releases/latest';
+  const releasesUrl = 'https://github.com/DD4SN/HolodoriCalc/releases';
+  const cacheKey = 'holodori-calc:latest-release';
+  const cacheDuration = 6 * 60 * 60 * 1000;
+
+  let status: 'checking' | 'current' | 'available' | 'failed' = 'checking';
+  let latestRelease: GitHubRelease | null = null;
+
+  function versionParts(version: string): number[] {
+    return version.replace(/^v/i, '').split('-', 1)[0].split('.').map((part) => Number.parseInt(part, 10) || 0);
+  }
+
+  function isNewerVersion(candidate: string, current: string): boolean {
+    const candidateParts = versionParts(candidate);
+    const currentParts = versionParts(current);
+    const length = Math.max(candidateParts.length, currentParts.length, 3);
+
+    for (let index = 0; index < length; index += 1) {
+      const difference = (candidateParts[index] ?? 0) - (currentParts[index] ?? 0);
+      if (difference !== 0) return difference > 0;
+    }
+
+    return false;
+  }
+
+  function isRelease(value: unknown): value is GitHubRelease {
+    if (!value || typeof value !== 'object') return false;
+    const release = value as Partial<GitHubRelease>;
+    return typeof release.tag_name === 'string'
+      && typeof release.html_url === 'string'
+      && Array.isArray(release.assets);
+  }
+
+  function applyRelease(release: GitHubRelease): void {
+    latestRelease = release;
+    status = isNewerVersion(release.tag_name, currentVersion) ? 'available' : 'current';
+  }
+
+  function readCachedRelease(): CachedRelease | null {
+    try {
+      const parsed = JSON.parse(localStorage.getItem(cacheKey) ?? 'null') as Partial<CachedRelease> | null;
+      if (!parsed || typeof parsed.checkedAt !== 'number' || !isRelease(parsed.release)) return null;
+      return parsed as CachedRelease;
+    } catch {
+      return null;
+    }
+  }
+
+  async function checkLatestRelease(): Promise<void> {
+    const cached = readCachedRelease();
+    if (cached && Date.now() - cached.checkedAt < cacheDuration) {
+      applyRelease(cached.release);
+      return;
+    }
+
+    const controller = new AbortController();
+    const timeout = window.setTimeout(() => controller.abort(), 6000);
+
+    try {
+      const response = await fetch(releaseApiUrl, {
+        headers: { Accept: 'application/vnd.github+json' },
+        signal: controller.signal
+      });
+      if (!response.ok) throw new Error(`GitHub release lookup failed: ${response.status}`);
+
+      const release: unknown = await response.json();
+      if (!isRelease(release) || release.draft || release.prerelease) throw new Error('Invalid GitHub release response');
+
+      localStorage.setItem(cacheKey, JSON.stringify({ checkedAt: Date.now(), release } satisfies CachedRelease));
+      applyRelease(release);
+    } catch {
+      if (cached) applyRelease(cached.release);
+      else status = 'failed';
+    } finally {
+      window.clearTimeout(timeout);
+    }
+  }
+
+  function downloadUrl(release: GitHubRelease): string {
+    const zip = release.assets.find((asset) => /^HolodoriCalc-offline-v.+\.zip$/i.test(asset.name));
+    return zip?.browser_download_url ?? release.html_url;
+  }
+
+  onMount(() => {
+    void checkLatestRelease();
+  });
+</script>
+
+<aside class:available={status === 'available'} class="update-notice" aria-live="polite">
+  <div class="version-summary">
+    <span class="label">현재 버전</span>
+    <strong>v{currentVersion}</strong>
+    {#if status === 'checking'}
+      <span class="status">최신 버전을 확인하고 있습니다.</span>
+    {:else if status === 'available' && latestRelease}
+      <span class="status"><b>v{latestRelease.tag_name.replace(/^v/i, '')}</b> 업데이트를 사용할 수 있습니다.</span>
+    {:else if status === 'current'}
+      <span class="status">최신 버전입니다.</span>
+    {:else}
+      <span class="status">업데이트를 확인할 수 없습니다.</span>
+    {/if}
+  </div>
+
+  {#if status === 'available' && latestRelease}
+    <a class="action primary" href={downloadUrl(latestRelease)} target="_blank" rel="noreferrer">최신 버전 다운로드 <span aria-hidden="true">→</span></a>
+  {:else}
+    <a class="action" href={releasesUrl} target="_blank" rel="noreferrer">릴리즈 보기 <span aria-hidden="true">→</span></a>
+  {/if}
+</aside>
+
+<style>
+  .update-notice { display: flex; align-items: center; justify-content: space-between; gap: 24px; margin-bottom: 12px; padding: 14px 18px; border: 1px solid #2c3440; border-radius: 12px; background: #151a22; }
+  .update-notice.available { border-color: rgb(237 139 181 / 38%); background: rgb(237 139 181 / 8%); }
+  .version-summary { display: flex; align-items: baseline; min-width: 0; gap: 10px; }
+  .label { color: #7f8998; font-size: 13px; font-weight: 800; }
+  strong { color: #eef1f5; font-size: 15px; }
+  .status { color: #a4adba; font-size: 14px; }
+  .status b { color: #f0a1c3; }
+  .action { flex: 0 0 auto; color: #aab3c0; font-size: 14px; font-weight: 800; text-decoration: none; }
+  .action.primary { color: #f2a6c6; }
+  .action span { margin-left: 4px; }
+  .action:hover { color: #f2a6c6; }
+  .action:focus-visible { outline: 3px solid rgb(239 139 182 / 28%); outline-offset: 3px; }
+
+  @media (max-width: 680px) {
+    .update-notice { align-items: flex-start; flex-direction: column; gap: 8px; }
+    .version-summary { align-items: flex-start; flex-wrap: wrap; }
+  }
+</style>
diff --git a/src/lib/styles/layout-tokens.css b/src/lib/styles/layout-tokens.css
index f24fb2a..f79bc72 100644
--- a/src/lib/styles/layout-tokens.css
+++ b/src/lib/styles/layout-tokens.css
@@ -1,8 +1,8 @@
 :root {
   --page-max-width: 1520px;
   --page-gutter: clamp(40px, 5vw, 96px);
-  --page-title-size: 72px;
-  --page-content-top: 48px;
+  --page-title-size: 40px;
+  --page-content-top: 24px;
   --page-header-bottom: 28px;
   --page-description-size: 16px;
 }
diff --git a/src/routes/+page.svelte b/src/routes/+page.svelte
index f0df07b..db66ef5 100644
--- a/src/routes/+page.svelte
+++ b/src/routes/+page.svelte
@@ -1,9 +1,15 @@
+<script lang="ts">
+  import UpdateNotice from '$lib/components/UpdateNotice.svelte';
+</script>
+
 <svelte:head>
   <title>홀로도리 계산기</title>
   <meta name="description" content="홀로라이브 드림즈의 편성, 스킬 순서와 멤버 보드를 분석하는 계산기" />
 </svelte:head>
 
 <main>
+  <UpdateNotice />
+
   <aside class="start-guide" aria-label="시작 안내">
     <p><span>처음 사용한다면</span><strong>사용자 데이터를 먼저 설정하세요.</strong> 보유 카드와 개화 단계, 멤버별 보드를 실제 분석에 반영할 수 있습니다.</p>
     <a href="/data">설정하기 <span aria-hidden="true">→</span></a>