diff --git a/src/components/Header.astro b/src/components/Header.astro
index ffe096a..4a458c0 100644
--- a/src/components/Header.astro
+++ b/src/components/Header.astro
@@ -24,6 +24,7 @@ const t = getTranslations(lang);
     .header-nav h1 a {
         color: inherit;
         text-decoration: none;
+        display: block;
     }
 
     .site-header {
@@ -31,14 +32,11 @@ const t = getTranslations(lang);
         padding-top: 0.5rem;
     }
 
-    .site-header .header-nav h1 {
-        font-size: 2.5rem;
-    }
-
     .theme-icon-wrap {
         position: absolute;
         top: 0;
         right: 0;
+        z-index: 2;
     }
 
     .header-nav {
@@ -50,5 +48,23 @@ const t = getTranslations(lang);
     .header-nav h1 {
         margin: 0;
         font-style: italic;
+        line-height: 1.1;
+
+        /* 给右上角 ThemeIcon 留空间 */
+        max-width: calc(100% - 4rem);
+
+        /* 桌面正常，手机自动缩小 */
+        font-size: clamp(1.6rem, 6vw, 2.5rem);
+    }
+
+    @media (max-width: 768px) {
+        .site-header {
+            padding-top: 0.25rem;
+        }
+
+        .header-nav h1 {
+            max-width: calc(100% - 3.5rem);
+            font-size: clamp(1.25rem, 7vw, 2rem);
+        }
     }
 </style>
diff --git a/src/components/Navigation.astro b/src/components/Navigation.astro
index b978f2d..73050ca 100644
--- a/src/components/Navigation.astro
+++ b/src/components/Navigation.astro
@@ -5,19 +5,29 @@ const lang = getLangFromUrl(Astro.url);
 const t = getTranslations(lang);
 ---
 
-<nav class="site-nav">
-    <a href={`/${lang}`} data-astro-reload>{t.nav.home}</a>
-    <a href={`/${lang}/about`}>{t.nav.about}</a>
-    <a href={`/${lang}/tags`}>{t.nav.tags}</a>
-    <a href={`/${lang}/timeline`}>{t.nav.timeline}</a>
-    <a href={`/${lang}/friends`}>{t.nav.friends}</a>
+<nav class="site-nav" aria-label="Site navigation">
+    <div class="site-nav-desktop">
+        <a href={`/${lang}`} data-astro-reload>{t.nav.home}</a>
+        <a href={`/${lang}/about`}>{t.nav.about}</a>
+        <a href={`/${lang}/tags`}>{t.nav.tags}</a>
+        <a href={`/${lang}/timeline`}>{t.nav.timeline}</a>
+        <a href={`/${lang}/friends`}>{t.nav.friends}</a>
+    </div>
+
+    <details class="site-nav-mobile">
+        <summary>☰ {lang === "zh" ? "导航栏" : "Menu"}</summary>
+        <div class="dropdown-menu">
+            <a href={`/${lang}`} data-astro-reload>{t.nav.home}</a>
+            <a href={`/${lang}/about`}>{t.nav.about}</a>
+            <a href={`/${lang}/tags`}>{t.nav.tags}</a>
+            <a href={`/${lang}/timeline`}>{t.nav.timeline}</a>
+            <a href={`/${lang}/friends`}>{t.nav.friends}</a>
+        </div>
+    </details>
 </nav>
 
 <style>
     .site-nav {
-        display: flex;
-        gap: 1.5rem;
-        align-items: center;
         margin: 1rem 0;
         padding-bottom: 3rem;
         position: relative;
@@ -50,6 +60,12 @@ const t = getTranslations(lang);
         );
     }
 
+    .site-nav-desktop {
+        display: flex;
+        gap: 1.5rem;
+        align-items: center;
+    }
+
     .site-nav a {
         color: black;
         text-decoration: underline;
@@ -68,4 +84,72 @@ const t = getTranslations(lang);
     :global(.dark) .site-nav a:hover {
         color: #ddd;
     }
+
+    .site-nav-mobile {
+        display: none;
+        position: relative;
+    }
+
+    .site-nav-mobile summary {
+        list-style: none;
+        cursor: pointer;
+        display: inline-block;
+        font-weight: 700;
+        font-size: 1.1rem;
+        color: black;
+        text-decoration: underline;
+        user-select: none;
+    }
+
+    .site-nav-mobile summary::-webkit-details-marker {
+        display: none;
+    }
+
+    :global(.dark) .site-nav-mobile summary {
+        color: white;
+    }
+
+    .dropdown-menu {
+        position: absolute;
+        top: calc(100% + 0.75rem);
+        left: 0;
+        min-width: 180px;
+        display: flex;
+        flex-direction: column;
+        gap: 0.75rem;
+        padding: 0.9rem 1rem;
+        background: #fffaf5;
+        border: 2px dashed #8b5e3c;
+        border-radius: 0;
+        z-index: 20;
+    }
+
+    .dropdown-menu a {
+        font-size: 1rem;
+        text-decoration: none;
+        color: black;
+    }
+
+    .dropdown-menu a:hover {
+        text-decoration: underline;
+    }
+
+    :global(.dark) .dropdown-menu {
+        background: #1f1b18;
+        border-color: #c8a98a;
+    }
+
+    :global(.dark) .dropdown-menu a {
+        color: white;
+    }
+
+    @media (max-width: 768px) {
+        .site-nav-desktop {
+            display: none;
+        }
+
+        .site-nav-mobile {
+            display: block;
+        }
+    }
 </style>