diff --git a/public/checklist.html b/public/checklist.html
index 3d0a89d..1a93020 100644
--- a/public/checklist.html
+++ b/public/checklist.html
@@ -112,8 +112,11 @@
         <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="Close"></button>
       </div>
       <div class="modal-body text-center">
-        <video id="rewardVideo" width="75%" controls>
-          <source src="video/reward.mp4" type="video/mp4">
+        <div id="completion-modal-custom" class="text-start d-none"></div>
+        <div id="completion-modal-text" class="text-start mb-3" style="white-space: pre-wrap;"></div>
+
+        <video id="rewardVideo" width="75%" controls class="d-none">
+          <source id="rewardVideoSource" src="video/reward.mp4" type="video/mp4">
           Votre navigateur ne supporte pas la vidéo.
         </video>
       </div>
diff --git a/routes/settings.js b/routes/settings.js
index c7d68b3..6a41d87 100644
--- a/routes/settings.js
+++ b/routes/settings.js
@@ -7,6 +7,14 @@ const Movie = require("../models/Movie");
 const router = express.Router();
 
 const ACTIVE_YEAR_KEY = "active_oscar_year";
+const COMPLETION_MODAL_KEY = "completion_modal_content";
+
+const DEFAULT_COMPLETION_MODAL = Object.freeze({
+  title: "Félicitations! very nice 🎉🎉🎉",
+  bodyText: "",
+  videoSrc: "video/reward.mp4",
+  bodyHtml: "",
+});
 
 function parseOscarYear(raw) {
   if (raw === undefined || raw === null || raw === "") return null;
@@ -16,6 +24,34 @@ function parseOscarYear(raw) {
   return n;
 }
 
+function sanitizeHtml(raw) {
+  // Basic, defensive sanitization (admin-controlled input, rendered for all users).
+  // We remove script tags and inline event handlers. This is not a complete HTML sanitizer.
+  const html = String(raw || "");
+  const withoutScripts = html.replace(/<script\b[\s\S]*?<\/script>/gi, "");
+  const withoutOnAttrs = withoutScripts
+    .replace(/\son\w+="[^"]*"/gi, "")
+    .replace(/\son\w+='[^']*'/gi, "")
+    .replace(/\son\w+=\S+/gi, "");
+  return withoutOnAttrs.trim();
+}
+
+function normalizeCompletionModal(rawValue) {
+  const value = rawValue && typeof rawValue === "object" && !Array.isArray(rawValue) ? rawValue : {};
+
+  const title = typeof value.title === "string" ? value.title : DEFAULT_COMPLETION_MODAL.title;
+  const bodyText = typeof value.bodyText === "string" ? value.bodyText : DEFAULT_COMPLETION_MODAL.bodyText;
+  const videoSrc = typeof value.videoSrc === "string" ? value.videoSrc : DEFAULT_COMPLETION_MODAL.videoSrc;
+  const bodyHtml = typeof value.bodyHtml === "string" ? value.bodyHtml : DEFAULT_COMPLETION_MODAL.bodyHtml;
+
+  return {
+    title: String(title || "").slice(0, 200).trim() || DEFAULT_COMPLETION_MODAL.title,
+    bodyText: String(bodyText || "").slice(0, 8000),
+    videoSrc: String(videoSrc || "").slice(0, 2048).trim(),
+    bodyHtml: sanitizeHtml(String(bodyHtml || "").slice(0, 20000)),
+  };
+}
+
 async function getOrInitActiveYear() {
   const existing = await Setting.findOne({ key: ACTIVE_YEAR_KEY });
   if (existing && typeof existing.value === "number") return existing.value;
@@ -78,5 +114,44 @@ router.put("/year", async (req, res) => {
   }
 });
 
+// Public: get the "100% completion" modal content for checklist.
+router.get("/completion-modal", async (req, res) => {
+  try {
+    const existing = await Setting.findOne({ key: COMPLETION_MODAL_KEY }).select("value");
+    const normalized = normalizeCompletionModal(existing?.value);
+    return res.status(200).json(normalized);
+  } catch (err) {
+    // If DB is down, still return a sane default so the client can render.
+    return res.status(200).json(DEFAULT_COMPLETION_MODAL);
+  }
+});
+
+// Admin-only: set the "100% completion" modal content for checklist.
+router.put("/completion-modal", async (req, res) => {
+  const token = req.headers.authorization?.split(" ")[1];
+  if (!token) return res.status(401).json({ message: "Authentication token is required" });
+
+  try {
+    const decoded = jwt.verify(token, process.env.JWT_SECRET);
+    if (!decoded.admin) {
+      return res.status(403).json({ message: "You do not have admin privileges" });
+    }
+
+    const normalized = normalizeCompletionModal(req.body);
+    const updated = await Setting.findOneAndUpdate(
+      { key: COMPLETION_MODAL_KEY },
+      { $set: { value: normalized } },
+      { upsert: true, new: true }
+    ).select("value");
+
+    return res.status(200).json(normalizeCompletionModal(updated?.value));
+  } catch (err) {
+    if (err instanceof jwt.JsonWebTokenError) {
+      return res.status(401).json({ message: "Invalid or expired token" });
+    }
+    return res.status(500).json({ error: err.message });
+  }
+});
+
 module.exports = router;