fmt-diff2.txt

diff --git a/src/components/MobileTOC.svelte b/src/components/MobileTOC.svelte
index ad2574c..56c3766 100644
--- a/src/components/MobileTOC.svelte
+++ b/src/components/MobileTOC.svelte
@@ -314,16 +314,16 @@ if (typeof window !== "undefined") {
 }
 </script>
 
-<!-- TOC toggle button for mobile -->
-<!--
+<!-- TOC toggle button：可见性由 toc-layout.js 写入的 html[data-toc-layout="narrow"] 驱动
+     （宽屏文章页用右侧栏目录，窄屏/宽度不足时退化到此入口；不再用固定断点隐藏） -->
 <button
 	on:click={togglePanel}
 	aria-label="Table of Contents"
 	id="mobile-toc-switch"
-	class="btn-plain scale-animation rounded-lg h-11 w-11 active:scale-90 lg:!hidden theme-switch-btn"
+	class="btn-plain scale-animation rounded-lg h-11 w-11 active:scale-90 theme-switch-btn"
 >
 	<Icon icon="material-symbols:format-list-bulleted" class="text-[1.25rem]" />
-</button>-->
+</button>
 
 <!-- Mobile TOC Panel -->
 <div 
@@ -394,8 +394,18 @@ if (typeof window !== "undefined") {
 </div>
 
 <style>
+	/* 26.09.06：入口按钮默认隐藏，仅在窄屏/宽度不足（narrow）模式显示 */
+	#mobile-toc-switch {
+		display: none;
+	}
+
+	:global(html[data-toc-layout="narrow"]) #mobile-toc-switch {
+		display: inline-flex;
+	}
+
 	.mobile-toc-panel {
-		max-height: calc(100vh - 120px);
+		/* 与右侧栏目录共用同一高度上限（已为回顶按钮预留间距），避免面板与按钮重叠 */
+		max-height: var(--toc-max-h, calc(100vh - 120px));
 		overflow-y: auto;
 		background: var(--card-bg);
 		border: 1px solid var(--line-color);