diff --git a/src/components/ui.rs b/src/components/ui.rs
index b307f6a..225002b 100644
--- a/src/components/ui.rs
+++ b/src/components/ui.rs
@@ -192,6 +192,43 @@ pub fn EmptyState(message: &'static str, variant: &'static str) -> Element {
     }
 }
 
+/// Tooltip 定位样式（胶囊：黑底白字，hover 显现）。
+const TOOLTIP_STYLE: &str =
+    "pointer-events-none absolute left-1/2 -translate-x-1/2 px-3 py-1.5 text-xs font-medium whitespace-nowrap rounded-lg opacity-0 group-hover:opacity-100 transition-opacity duration-200 bg-paper-primary text-paper-theme shadow-lg z-50";
+
+/// Tooltip 包裹组件。
+///
+/// 将任意触发器（按钮等）包裹后，鼠标 hover 时在上方或下方居中弹出提示。
+/// 用 CSS `group` + `group-hover:opacity-100` 实现，无 JS 状态，`pointer-events-none`
+/// 保证不拦截点击。
+///
+/// Props：
+/// - `tip`：提示文案
+/// - `children`：触发器元素（按钮 / 链接等）
+/// - `placement`：弹出方向，`"top"`（默认）或 `"bottom"`
+///
+/// 注意：父容器若有 `overflow-hidden` 会裁掉 tooltip，此时应选朝外的方向
+/// （如表格行在 `overflow-hidden` 容器内，朝上的 tooltip 才不会被裁）。
+#[component]
+pub fn Tooltip(
+    tip: String,
+    children: Element,
+    #[props(default = "top")] placement: &'static str,
+) -> Element {
+    // 朝上：tooltip 在触发器上方（bottom-full + mb-2）；朝下：在下方（top-full + mt-2）。
+    let position_class = if placement == "bottom" {
+        "top-full mt-2"
+    } else {
+        "bottom-full mb-2"
+    };
+    rsx! {
+        div { class: "group relative",
+            {children}
+            div { class: "{TOOLTIP_STYLE} {position_class}", "{tip}" }
+        }
+    }
+}
+
 static TAB_GROUP_ID: std::sync::atomic::AtomicUsize = std::sync::atomic::AtomicUsize::new(0);
 
 /// 筛选选项卡组件。
diff --git a/src/pages/admin/posts.rs b/src/pages/admin/posts.rs
index c8c2754..ba480d8 100644
--- a/src/pages/admin/posts.rs
+++ b/src/pages/admin/posts.rs
@@ -16,8 +16,8 @@ use crate::components::empty_state::{EmptyState, EmptyStateAction};
 use crate::components::skeletons::delayed_skeleton::DelayedSkeleton;
 use crate::components::skeletons::posts_skeleton::PostsSkeleton;
 use crate::components::ui::{
-    Pagination, StatusBadge, ADMIN_ROW_HOVER, ADMIN_TABLE_CLASS, BTN_TEXT_ACCENT, BTN_TEXT_RED,
-    SPINNER_SVG,
+    Pagination, StatusBadge, Tooltip, ADMIN_ROW_HOVER, ADMIN_TABLE_CLASS, BTN_TEXT_ACCENT,
+    BTN_TEXT_RED, SPINNER_SVG,
 };
 use crate::hooks::query::use_paginated;
 use crate::models::post::PostListItem;
@@ -237,7 +237,9 @@ fn RebuildCacheBar(
     rsx! {
         // 仅渲染按钮行本身：结果消息已上提到 PostsPage，作为独立状态行进入文档流。
         div { class: "flex items-center gap-3",
-            div { class: "group relative",
+            Tooltip {
+                tip: "重建 content_html 为空的文章渲染缓存".to_string(),
+                placement: "bottom",
                 button {
                     class: if rebuilding() { "relative px-4 py-2 rounded-full text-sm font-medium cursor-not-allowed text-paper-secondary border border-paper-border" } else { "px-4 py-2 rounded-full text-sm font-medium cursor-pointer text-paper-primary border border-paper-border hover:border-paper-accent hover:text-paper-accent transition-all" },
                     disabled: rebuilding(),
@@ -253,11 +255,10 @@ fn RebuildCacheBar(
                         }
                     }
                 }
-                div { class: "pointer-events-none absolute top-full left-1/2 -translate-x-1/2 mt-2 px-3 py-1.5 text-xs font-medium whitespace-nowrap rounded-lg opacity-0 group-hover:opacity-100 transition-opacity duration-200 bg-paper-primary text-paper-theme shadow-lg z-50",
-                    "重建 content_html 为空的文章渲染缓存"
-                }
             }
-            div { class: "group relative",
+            Tooltip {
+                tip: "重建所有文章的渲染缓存（含已有内容）".to_string(),
+                placement: "bottom",
                 button {
                     class: if rebuilding() { "relative px-4 py-2 rounded-full text-sm font-medium cursor-not-allowed text-paper-secondary border border-paper-border" } else { "px-4 py-2 rounded-full text-sm font-medium cursor-pointer text-paper-primary border border-paper-border hover:border-paper-accent hover:text-paper-accent transition-all" },
                     disabled: rebuilding(),
@@ -273,9 +274,6 @@ fn RebuildCacheBar(
                         }
                     }
                 }
-                div { class: "pointer-events-none absolute top-full left-1/2 -translate-x-1/2 mt-2 px-3 py-1.5 text-xs font-medium whitespace-nowrap rounded-lg opacity-0 group-hover:opacity-100 transition-opacity duration-200 bg-paper-primary text-paper-theme shadow-lg z-50",
-                    "重建所有文章的渲染缓存（含已有内容）"
-                }
             }
         }
     }
@@ -317,22 +315,25 @@ fn PostRow(
                         to: Route::WriteEdit { id: post.id },
                         "编辑"
                     }
-                    button {
-                        class: if rebuilding {
-                            "relative inline-flex items-center text-xs text-paper-accent cursor-not-allowed"
-                        } else {
-                            BTN_TEXT_ACCENT
-                        },
-                        disabled: rebuilding,
-                        onclick: move |_| on_rebuild.call(post.id),
-                        span {
-                            class: if rebuilding { "opacity-40" } else { "" },
-                            "重建"
-                        }
-                        if rebuilding {
+                    Tooltip {
+                        tip: "重新渲染这篇文章的 HTML".to_string(),
+                        button {
+                            class: if rebuilding {
+                                "relative inline-flex items-center text-xs text-paper-accent cursor-not-allowed"
+                            } else {
+                                BTN_TEXT_ACCENT
+                            },
+                            disabled: rebuilding,
+                            onclick: move |_| on_rebuild.call(post.id),
                             span {
-                                class: "absolute inset-0 flex items-center justify-center",
-                                dangerous_inner_html: SPINNER_SVG,
+                                class: if rebuilding { "opacity-40" } else { "" },
+                                "重建"
+                            }
+                            if rebuilding {
+                                span {
+                                    class: "absolute inset-0 flex items-center justify-center",
+                                    dangerous_inner_html: SPINNER_SVG,
+                                }
                             }
                         }
                     }