diff --git a/.jules/palette.md b/.jules/palette.md
index 0bbf5248..10f84427 100644
--- a/.jules/palette.md
+++ b/.jules/palette.md
@@ -115,3 +115,6 @@
 ## $(date +%Y-%m-%d) - Prevent accidental data loss in inline editors
 **Learning:** Forms that take a long time to fill out (like a WBS editor) are prone to accidental closure by users pressing `Escape` or clicking cancel. This causes immediate data loss without any warning, resulting in frustration.
 **Action:** When working on editors that can be dismissed, track whether the user has modified any fields compared to their initial state. If there are changes, intercept the close action and present a confirmation dialog (`window.confirm`) to ensure they really want to discard their edits. Bypass this for intentional saves or explicit data overrides.
+## 2026-08-24 - Add keyboard accessibility to summary cards tooltips
+**Learning:** Pure informative elements using native `title` tooltips, like `.meta-value-card`, are inaccessible to keyboard and screen reader users unless explicitly made focusable. Adding `tabindex="0"` creates the focus point, while `role="note"` (or similar) gives context to screen readers, allowing the native tooltip to be announced. A dedicated focus ring in CSS is also essential for visual indication.
+**Action:** Always verify that informative UI blocks relying on `title` attributes for tooltips or supplementary info are reachable via the Tab key by verifying `tabindex` and an appropriate ARIA role.
diff --git a/index.html b/index.html
index d24b2a88..e978ac5c 100644
--- a/index.html
+++ b/index.html
@@ -29,18 +29,18 @@ <h1>ScopeWeave Planner</h1>
             <span>기준일</span>
             <input data-testid="base-date-input" id="base-date" type="date" />
           </label>
-          <div class="meta-value-card" title="프로젝트의 작업 기간(일수) 합계입니다.">
+          <div class="meta-value-card" title="프로젝트의 작업 기간(일수) 합계입니다." role="note" tabindex="0">
             <span class="meta-label">전체일수</span>
             <strong data-testid="summary-total-days" id="summary-total-days">0일</strong>
           </div>
         </div>
 
         <div class="meta-grid meta-grid-secondary">
-          <div class="meta-value-card accent-card plan-card" title="기간(일수) 가중치가 반영된 프로젝트 전체 계획 진척률입니다.">
+          <div class="meta-value-card accent-card plan-card" title="기간(일수) 가중치가 반영된 프로젝트 전체 계획 진척률입니다." role="note" tabindex="0">
             <span class="meta-label">계획진척률(누적)</span>
             <strong data-testid="summary-planned-progress" id="summary-planned-progress">0.00%</strong>
           </div>
-          <div class="meta-value-card accent-card actual-card" title="기간(일수) 가중치가 반영된 프로젝트 전체 실적 진척률입니다.">
+          <div class="meta-value-card accent-card actual-card" title="기간(일수) 가중치가 반영된 프로젝트 전체 실적 진척률입니다." role="note" tabindex="0">
             <span class="meta-label">실적진척률(누적)</span>
             <strong data-testid="summary-actual-progress" id="summary-actual-progress">0.00%</strong>
           </div>
diff --git a/styles.css b/styles.css
index 9d715f00..6d5300ca 100644
--- a/styles.css
+++ b/styles.css
@@ -360,7 +360,8 @@ button {
 .secondary-button:focus-visible,
 input:focus-visible,
 select:focus-visible,
-.gantt-bar:focus-visible {
+.gantt-bar:focus-visible,
+.meta-value-card:focus-visible {
   outline: 3px solid rgba(37, 99, 235, 0.5);
   outline-offset: 2px;
 }