diff --git a/src/layouts/BaseLayout.astro b/src/layouts/BaseLayout.astro
index c1c7e38..8b48452 100644
--- a/src/layouts/BaseLayout.astro
+++ b/src/layouts/BaseLayout.astro
@@ -54,9 +54,18 @@ const consoleSites = [
     <script is:inline>
       (() => {
         const storageKey = 'site-theme';
-        const savedTheme = localStorage.getItem(storageKey);
-        const systemTheme = window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light';
-        document.documentElement.dataset.theme = savedTheme || systemTheme;
+        const media = window.matchMedia('(prefers-color-scheme: dark)');
+        const getSystemTheme = () => (media.matches ? 'dark' : 'light');
+        const getSavedTheme = () => {
+          try {
+            const theme = localStorage.getItem(storageKey);
+            return theme === 'dark' || theme === 'light' ? theme : null;
+          } catch {
+            return null;
+          }
+        };
+
+        document.documentElement.dataset.theme = getSavedTheme() || getSystemTheme();
       })();
     </script>
     <link rel="stylesheet" href={siteConfig.cdn.instantsearchCss} />
@@ -257,25 +266,53 @@ const consoleSites = [
         const button = document.querySelector('[data-theme-toggle]');
         const media = window.matchMedia('(prefers-color-scheme: dark)');
         const getSystemTheme = () => (media.matches ? 'dark' : 'light');
-        const getTheme = () => localStorage.getItem(storageKey) || getSystemTheme();
+        const getSavedTheme = () => {
+          try {
+            const theme = localStorage.getItem(storageKey);
+            return theme === 'dark' || theme === 'light' ? theme : null;
+          } catch {
+            return null;
+          }
+        };
+        const setSavedTheme = (theme) => {
+          try {
+            if (theme === getSystemTheme()) localStorage.removeItem(storageKey);
+            else localStorage.setItem(storageKey, theme);
+          } catch {
+            // localStorage can be unavailable in strict privacy modes.
+          }
+        };
+        const getTheme = () => getSavedTheme() || getSystemTheme();
 
         function applyTheme(theme) {
           root.dataset.theme = theme;
+          root.dataset.themeMode = getSavedTheme() ? 'manual' : 'auto';
           button?.setAttribute('aria-label', theme === 'dark' ? '切换到日间模式' : '切换到夜间模式');
-          button?.setAttribute('title', theme === 'dark' ? '切换到日间模式' : '切换到夜间模式');
+          button?.setAttribute(
+            'title',
+            getSavedTheme()
+              ? (theme === 'dark' ? '切换到日间模式' : '切换到夜间模式')
+              : `跟随系统：${theme === 'dark' ? '夜间' : '日间'}模式`
+          );
         }
 
         applyTheme(getTheme());
 
         button?.addEventListener('click', () => {
           const nextTheme = root.dataset.theme === 'dark' ? 'light' : 'dark';
-          localStorage.setItem(storageKey, nextTheme);
+          setSavedTheme(nextTheme);
           applyTheme(nextTheme);
         });
 
-        media.addEventListener('change', () => {
-          if (!localStorage.getItem(storageKey)) applyTheme(getSystemTheme());
-        });
+        const handleSystemThemeChange = () => {
+          if (!getSavedTheme()) applyTheme(getSystemTheme());
+        };
+
+        if (typeof media.addEventListener === 'function') {
+          media.addEventListener('change', handleSystemThemeChange);
+        } else if (typeof media.addListener === 'function') {
+          media.addListener(handleSystemThemeChange);
+        }
       })();
 
       (() => {
diff --git a/src/pages/posts/[slug].astro b/src/pages/posts/[slug].astro
index e088bfc..5eddfe4 100644
--- a/src/pages/posts/[slug].astro
+++ b/src/pages/posts/[slug].astro
@@ -390,9 +390,17 @@ const relatedPosts = allPosts
       toggleButton.textContent = '展开';
       toggleButton.setAttribute('aria-expanded', 'false');
 
+      const expandCue = document.createElement('button');
+      expandCue.className = 'code-block-expand-cue';
+      expandCue.type = 'button';
+      expandCue.setAttribute('aria-label', 'Expand code block');
+      expandCue.setAttribute('aria-expanded', 'false');
+      expandCue.innerHTML = '<span aria-hidden="true"></span>';
+
       toolbar.append(copyButton, toggleButton);
       header.append(language, toolbar);
       wrapper.appendChild(header);
+      wrapper.appendChild(expandCue);
 
       const codeLines = [...code.querySelectorAll(':scope > .line')];
       if (codeLines.length > 0) {
@@ -421,11 +429,15 @@ const relatedPosts = allPosts
         }
       });
 
-      toggleButton.addEventListener('click', () => {
+      function toggleExpanded() {
         const isExpanded = wrapper.classList.toggle('is-expanded');
         toggleButton.textContent = isExpanded ? '收起' : '展开';
         toggleButton.setAttribute('aria-expanded', String(isExpanded));
-      });
+        expandCue.setAttribute('aria-expanded', String(isExpanded));
+      }
+
+      toggleButton.addEventListener('click', toggleExpanded);
+      expandCue.addEventListener('click', toggleExpanded);
     });
   })();
 </script>
diff --git a/src/styles/site.css b/src/styles/site.css
index 909f449..b26cf26 100644
--- a/src/styles/site.css
+++ b/src/styles/site.css
@@ -19,14 +19,14 @@
 
 :root[data-theme='dark'] {
   color-scheme: dark;
-  --bg: #0f171a;
-  --surface: #162225;
-  --text: #e9f0ee;
-  --muted: #a7b4b1;
-  --line: rgba(174, 205, 197, 0.18);
-  --accent: #72ded2;
-  --accent-strong: #9af0d6;
-  --shadow: 0 18px 48px rgba(0, 0, 0, 0.28);
+  --bg: #0b1014;
+  --surface: #141b21;
+  --text: #e7edf0;
+  --muted: #9ba9b1;
+  --line: rgba(166, 184, 194, 0.2);
+  --accent: #7dd3c7;
+  --accent-strong: #b7e7d4;
+  --shadow: 0 18px 52px rgba(0, 0, 0, 0.36);
 }
 
 * {
@@ -49,7 +49,7 @@ body {
 
 :root[data-theme='dark'] body {
   background:
-    linear-gradient(rgba(8, 13, 16, 0.86), rgba(10, 17, 20, 0.94)),
+    linear-gradient(rgba(7, 10, 14, 0.9), rgba(8, 13, 17, 0.96)),
     url('/images/background.png') center top / cover fixed;
 }
 
@@ -563,20 +563,20 @@ a {
 }
 
 :root[data-theme='dark'] .nav {
-  border-color: rgba(174, 205, 197, 0.2);
+  border-color: rgba(166, 184, 194, 0.2);
   background:
-    linear-gradient(135deg, rgba(29, 47, 51, 0.78), rgba(14, 23, 27, 0.54)),
-    rgba(12, 19, 22, 0.62);
+    linear-gradient(135deg, rgba(25, 35, 42, 0.82), rgba(10, 15, 20, 0.66)),
+    rgba(10, 15, 20, 0.68);
   box-shadow:
     inset 0 1px 0 rgba(255, 255, 255, 0.12),
     inset 0 -18px 38px rgba(0, 0, 0, 0.18),
-    0 18px 54px rgba(0, 0, 0, 0.34);
+    0 18px 54px rgba(0, 0, 0, 0.42);
 }
 
 :root[data-theme='dark'] .nav::before {
   background:
-    radial-gradient(circle at 18% 0%, rgba(114, 222, 210, 0.18), transparent 32%),
-    linear-gradient(90deg, rgba(255, 255, 255, 0.08), transparent 42%, rgba(114, 222, 210, 0.1));
+    radial-gradient(circle at 18% 0%, rgba(125, 211, 199, 0.16), transparent 32%),
+    linear-gradient(90deg, rgba(255, 255, 255, 0.07), transparent 42%, rgba(125, 211, 199, 0.08));
 }
 
 :root[data-theme='dark'] .nav::after {
@@ -589,8 +589,8 @@ a {
 :root[data-theme='dark'] .nav-console:hover,
 :root[data-theme='dark'] .theme-toggle:hover,
 :root[data-theme='dark'] .nav-menu-toggle:hover {
-  border-color: rgba(114, 222, 210, 0.26);
-  background: rgba(114, 222, 210, 0.12);
+  border-color: rgba(125, 211, 199, 0.28);
+  background: rgba(125, 211, 199, 0.11);
   box-shadow:
     inset 0 1px 0 rgba(255, 255, 255, 0.12),
     0 8px 18px rgba(0, 0, 0, 0.18);
@@ -601,14 +601,14 @@ a {
 }
 
 :root[data-theme='dark'] .control-console-panel {
-  border-color: rgba(174, 205, 197, 0.18);
+  border-color: rgba(166, 184, 194, 0.2);
   background:
-    radial-gradient(circle at 14% 0%, rgba(114, 222, 210, 0.1), transparent 34%),
-    linear-gradient(145deg, rgba(28, 43, 47, 0.88), rgba(12, 22, 25, 0.8)),
-    rgba(17, 28, 31, 0.82);
+    radial-gradient(circle at 14% 0%, rgba(125, 211, 199, 0.08), transparent 34%),
+    linear-gradient(145deg, rgba(24, 34, 42, 0.9), rgba(10, 17, 22, 0.84)),
+    rgba(14, 22, 28, 0.84);
   box-shadow:
     inset 0 1px 0 rgba(255, 255, 255, 0.1),
-    0 28px 80px rgba(0, 0, 0, 0.38);
+    0 28px 80px rgba(0, 0, 0, 0.46);
 }
 
 :root[data-theme='dark'] .control-console-head h2,
@@ -620,8 +620,8 @@ a {
 :root[data-theme='dark'] .control-site-card,
 :root[data-theme='dark'] .control-console-info section,
 :root[data-theme='dark'] .control-console-close {
-  border-color: rgba(114, 222, 210, 0.2);
-  background: rgba(114, 222, 210, 0.1);
+  border-color: rgba(125, 211, 199, 0.2);
+  background: rgba(125, 211, 199, 0.08);
   box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.08);
 }
 
@@ -631,35 +631,35 @@ a {
 }
 
 :root[data-theme='dark'] .custom-context-menu {
-  border-color: rgba(174, 205, 197, 0.2);
+  border-color: rgba(166, 184, 194, 0.2);
   color: #d8e5e2;
   background:
-    linear-gradient(145deg, rgba(31, 48, 52, 0.88), rgba(13, 23, 26, 0.78)),
-    rgba(15, 25, 28, 0.82);
+    linear-gradient(145deg, rgba(27, 39, 47, 0.9), rgba(10, 17, 22, 0.82)),
+    rgba(14, 22, 28, 0.84);
   box-shadow:
     inset 0 1px 0 rgba(255, 255, 255, 0.1),
-    0 18px 42px rgba(0, 0, 0, 0.34);
+    0 18px 42px rgba(0, 0, 0, 0.42);
 }
 
 :root[data-theme='dark'] .context-menu-nav :where(a, button) {
-  border-color: rgba(174, 205, 197, 0.16);
-  color: #b7c7c4;
+  border-color: rgba(166, 184, 194, 0.16);
+  color: #b7c3c8;
   background: rgba(255, 255, 255, 0.06);
   box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.08);
 }
 
 :root[data-theme='dark'] .context-menu-group {
-  border-top-color: rgba(174, 205, 197, 0.16);
+  border-top-color: rgba(166, 184, 194, 0.16);
 }
 
 :root[data-theme='dark'] .custom-context-menu :where(a, button):hover,
 :root[data-theme='dark'] .custom-context-menu :where(a, button):focus-visible {
   color: var(--accent);
-  background: rgba(114, 222, 210, 0.11);
+  background: rgba(125, 211, 199, 0.1);
 }
 
 :root[data-theme='dark'] .custom-context-menu i {
-  color: #a8b8b5;
+  color: #a8b5ba;
 }
 
 .hero {
@@ -2235,6 +2235,7 @@ time {
 .prose .code-block.is-collapsible:not(.is-expanded)::after {
   content: "";
   position: absolute;
+  z-index: 1;
   right: 0;
   bottom: 0;
   left: 0;
@@ -2243,6 +2244,52 @@ time {
   pointer-events: none;
 }
 
+.code-block-expand-cue {
+  appearance: none;
+  -webkit-appearance: none;
+  position: absolute;
+  z-index: 3;
+  right: 50%;
+  bottom: 10px;
+  display: none;
+  width: 36px;
+  height: 28px;
+  align-items: center;
+  justify-content: center;
+  border: 1px solid rgba(255, 255, 255, 0.18);
+  border-radius: 999px;
+  padding: 0;
+  background: rgba(22, 31, 36, 0.72);
+  box-shadow: 0 8px 18px rgba(0, 0, 0, 0.18);
+  cursor: pointer;
+  transform: translateX(50%);
+  backdrop-filter: blur(8px);
+  -webkit-backdrop-filter: blur(8px);
+  transition:
+    border-color 0.2s ease,
+    background-color 0.2s ease,
+    transform 0.2s ease;
+}
+
+.code-block-expand-cue span {
+  width: 10px;
+  height: 10px;
+  border-right: 2px solid rgba(255, 255, 255, 0.9);
+  border-bottom: 2px solid rgba(255, 255, 255, 0.9);
+  transform: translateY(-2px) rotate(45deg);
+}
+
+.code-block-expand-cue:hover,
+.code-block-expand-cue:focus-visible {
+  border-color: rgba(255, 255, 255, 0.36);
+  background: rgba(62, 184, 190, 0.82);
+  transform: translateX(50%) translateY(-1px);
+}
+
+.prose .code-block.is-collapsible:not(.is-expanded) .code-block-expand-cue {
+  display: inline-flex;
+}
+
 .prose .code-block code {
   color: #e8edf2;
   line-height: 1.42;
@@ -3882,11 +3929,11 @@ meting-js {
   .pagination-link,
   .pagination-number
 ) {
-  border-color: rgba(174, 205, 197, 0.18);
+  border-color: rgba(166, 184, 194, 0.18);
   background:
-    radial-gradient(circle at 14% 0%, rgba(114, 222, 210, 0.1), transparent 34%),
-    linear-gradient(145deg, rgba(28, 43, 47, 0.82), rgba(12, 22, 25, 0.72)),
-    rgba(17, 28, 31, 0.74);
+    radial-gradient(circle at 14% 0%, rgba(125, 211, 199, 0.08), transparent 34%),
+    linear-gradient(145deg, rgba(24, 34, 42, 0.84), rgba(10, 17, 22, 0.76)),
+    rgba(14, 22, 28, 0.78);
   box-shadow: var(--shadow);
 }
 
@@ -3931,12 +3978,12 @@ meting-js {
 }
 
 :root[data-theme='dark'] .chart-legend-item {
-  border-color: rgba(174, 205, 197, 0.16);
+  border-color: rgba(166, 184, 194, 0.16);
   background: rgba(255, 255, 255, 0.05);
 }
 
 :root[data-theme='dark'] .pie-chart-track {
-  stroke: rgba(174, 205, 197, 0.16);
+  stroke: rgba(166, 184, 194, 0.16);
 }
 
 :root[data-theme='dark'] .line-chart-dot {
@@ -3954,9 +4001,9 @@ meting-js {
   .post-copyright-action,
   .post-copyright-icon
 ) {
-  border-color: rgba(114, 222, 210, 0.22);
+  border-color: rgba(125, 211, 199, 0.22);
   color: var(--accent);
-  background: rgba(114, 222, 210, 0.1);
+  background: rgba(125, 211, 199, 0.1);
   box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.08);
 }
 
@@ -3980,30 +4027,30 @@ meting-js {
 }
 
 :root[data-theme='dark'] .article-header-cover {
-  background: #0d1f21;
+  background: #0d171d;
 }
 
 :root[data-theme='dark'] .article-header-cover::before {
   background:
-    linear-gradient(180deg, rgba(5, 12, 14, 0.54), rgba(7, 19, 21, 0.22) 38%, rgba(3, 10, 11, 0.82)),
-    linear-gradient(90deg, rgba(5, 18, 20, 0.62), rgba(12, 60, 57, 0.16) 54%, rgba(5, 18, 20, 0.44));
+    linear-gradient(180deg, rgba(5, 9, 12, 0.58), rgba(8, 16, 20, 0.28) 38%, rgba(3, 8, 11, 0.86)),
+    linear-gradient(90deg, rgba(5, 13, 17, 0.66), rgba(20, 57, 58, 0.14) 54%, rgba(5, 13, 17, 0.48));
 }
 
 :root[data-theme='dark'] .prose .code-block {
-  border-color: rgba(114, 222, 210, 0.2);
-  background: rgba(5, 10, 12, 0.96);
-  box-shadow: 0 14px 32px rgba(0, 0, 0, 0.24);
+  border-color: rgba(125, 211, 199, 0.18);
+  background: rgba(5, 8, 12, 0.96);
+  box-shadow: 0 14px 32px rgba(0, 0, 0, 0.32);
 }
 
 :root[data-theme='dark'] .prose :not(pre) > code {
-  border-color: rgba(114, 222, 210, 0.22);
+  border-color: rgba(125, 211, 199, 0.22);
   color: var(--accent);
-  background: rgba(114, 222, 210, 0.1);
+  background: rgba(125, 211, 199, 0.1);
 }
 
 :root[data-theme='dark'] .butterfly-note {
   color: #dce9e6;
-  background: rgba(114, 222, 210, 0.08);
+  background: rgba(125, 211, 199, 0.08);
 }
 
 :root[data-theme='dark'] .butterfly-note--disabled {
@@ -4015,7 +4062,7 @@ meting-js {
 }
 
 :root[data-theme='dark'] .butterfly-hide-block__content {
-  border-left-color: rgba(114, 222, 210, 0.22);
+  border-left-color: rgba(125, 211, 199, 0.22);
 }
 
 :root[data-theme='dark'] .prose table {
@@ -4025,43 +4072,43 @@ meting-js {
 :root[data-theme='dark'] .prose thead th {
   color: #effaf7;
   background:
-    linear-gradient(135deg, rgba(40, 70, 70, 0.86), rgba(22, 41, 44, 0.76)),
-    rgba(13, 24, 27, 0.8);
+    linear-gradient(135deg, rgba(35, 55, 61, 0.86), rgba(18, 31, 38, 0.78)),
+    rgba(12, 21, 27, 0.84);
 }
 
 :root[data-theme='dark'] .prose tbody tr:nth-child(even) td {
-  background: rgba(114, 222, 210, 0.07);
+  background: rgba(125, 211, 199, 0.06);
 }
 
 :root[data-theme='dark'] .prose tbody tr:hover td {
-  background: rgba(114, 222, 210, 0.12);
+  background: rgba(125, 211, 199, 0.1);
 }
 
 :root[data-theme='dark'] .prose :where(th, td) {
-  border-color: rgba(114, 222, 210, 0.12);
+  border-color: rgba(125, 211, 199, 0.12);
 }
 
 :root[data-theme='dark'] .site-footer {
-  color: rgba(197, 214, 211, 0.74);
+  color: rgba(199, 211, 216, 0.76);
   background:
-    linear-gradient(180deg, rgba(12, 20, 23, 0.68), rgba(8, 14, 17, 0.88)),
-    rgba(8, 14, 17, 0.84);
+    linear-gradient(180deg, rgba(10, 16, 21, 0.7), rgba(6, 10, 14, 0.9)),
+    rgba(7, 11, 15, 0.86);
   box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.08);
 }
 
 :root[data-theme='dark'] .footer-socials a {
-  border-color: rgba(174, 205, 197, 0.18);
+  border-color: rgba(166, 184, 194, 0.18);
   color: rgba(218, 234, 231, 0.82);
   background:
-    linear-gradient(145deg, rgba(34, 51, 55, 0.78), rgba(14, 24, 27, 0.72)),
-    rgba(18, 29, 32, 0.72);
+    linear-gradient(145deg, rgba(28, 40, 48, 0.8), rgba(10, 17, 22, 0.74)),
+    rgba(14, 22, 28, 0.74);
   box-shadow:
     inset 0 1px 0 rgba(255, 255, 255, 0.08),
-    0 10px 24px rgba(0, 0, 0, 0.22);
+    0 10px 24px rgba(0, 0, 0, 0.3);
 }
 
 :root[data-theme='dark'] .footer-bottom {
-  border-top-color: rgba(174, 205, 197, 0.16);
+  border-top-color: rgba(166, 184, 194, 0.16);
 }
 
 @media (min-width: 960px) {