diff --git a/index.html b/index.html
index 39dc15b..a7eb62b 100644
--- a/index.html
+++ b/index.html
@@ -341,59 +341,446 @@
       ]
     </script>
 
-    <!-- Fallback: if script.js fails to load, render basic cards -->
+    <!-- Fallback: if script.js fails, run full-feature inline app -->
     <script>
-      setTimeout(() => {
-        if (window.__LINKS_APP_BOOTED__) return;
-        const grid = document.getElementById("grid");
-        const empty = document.getElementById("empty");
-        const dataEl = document.getElementById("linksData");
-        if (!grid || !dataEl) return;
-        try {
-          const links = JSON.parse(dataEl.textContent || "[]");
-          if (!Array.isArray(links) || links.length === 0) return;
-          const esc = (s) =>
-            String(s)
-              .replaceAll("&", "&amp;")
-              .replaceAll("<", "&lt;")
-              .replaceAll(">", "&gt;")
-              .replaceAll('"', "&quot;")
-              .replaceAll("'", "&#039;");
-          const domain = (u) => {
-            try {
-              return new URL(u).host;
-            } catch {
-              return String(u || "").replace(/^https?:\/\//i, "").split("/")[0] || "";
-            }
+      (function () {
+        function safeJsonParse(s, fallback) {
+          try {
+            return JSON.parse(s);
+          } catch {
+            return fallback;
+          }
+        }
+        function esc(s) {
+          return String(s)
+            .replaceAll("&", "&amp;")
+            .replaceAll("<", "&lt;")
+            .replaceAll(">", "&gt;")
+            .replaceAll('"', "&quot;")
+            .replaceAll("'", "&#039;");
+        }
+        function normalizeUrl(url) {
+          const u = String(url || "").trim();
+          if (!u) return "";
+          if (/^https?:\/\//i.test(u)) return u;
+          return "https://" + u;
+        }
+        function domain(u) {
+          try {
+            return new URL(u).host;
+          } catch {
+            return String(u || "").replace(/^https?:\/\//i, "").split("/")[0] || "";
+          }
+        }
+        function nowIso() {
+          return new Date().toISOString();
+        }
+
+        // Wait a tick for external script.js to possibly boot.
+        setTimeout(() => {
+          if (window.__LINKS_APP_BOOTED__) return;
+          window.__LINKS_APP_BOOTED__ = true;
+
+          const STORAGE_KEY = "links_home_v1";
+          const THEME_KEY = "links_home_theme_v1";
+
+          const el = {
+            q: document.getElementById("q"),
+            sort: document.getElementById("sort"),
+            onlyFav: document.getElementById("onlyFav"),
+            meta: document.getElementById("meta"),
+            grid: document.getElementById("grid"),
+            empty: document.getElementById("empty"),
+            btnAdd: document.getElementById("btnAdd"),
+            btnImport: document.getElementById("btnImport"),
+            btnExport: document.getElementById("btnExport"),
+            btnTheme: document.getElementById("btnTheme"),
+            toast: document.getElementById("toast"),
+            modal: document.getElementById("modal"),
+            btnClose: document.getElementById("btnClose"),
+            btnCancel: document.getElementById("btnCancel"),
+            form: document.getElementById("form"),
+            id: document.getElementById("id"),
+            title: document.getElementById("title"),
+            url: document.getElementById("url"),
+            description: document.getElementById("description"),
+            tags: document.getElementById("tags"),
+            favorite: document.getElementById("favorite"),
+            file: document.getElementById("file"),
           };
-          grid.innerHTML = links
-            .map((l) => {
-              const t = esc(l.title || domain(l.url) || "Link");
-              const d = esc(domain(l.url));
-              const u = esc(l.url || "#");
-              const desc = esc(l.description || "");
-              return `
-                <article class="card">
-                  <div class="card-head">
-                    <div class="card-title">
-                      <div class="favicon" aria-hidden="true"><div class="letter">${t.slice(0, 1)}</div></div>
-                      <div class="title-wrap">
-                        <div class="title">${t}</div>
-                        <div class="domain">${d}</div>
-                      </div>
+
+          function toast(msg) {
+            if (!el.toast) return;
+            el.toast.textContent = msg;
+            el.toast.hidden = false;
+            clearTimeout(toast._t);
+            toast._t = setTimeout(() => (el.toast.hidden = true), 2200);
+          }
+
+          function loadStore() {
+            const raw = localStorage.getItem(STORAGE_KEY);
+            const data = raw ? safeJsonParse(raw, null) : null;
+            const store = { overridesById: {}, tombstones: [], custom: [] };
+            if (!data || typeof data !== "object") return store;
+            if (data.overridesById && typeof data.overridesById === "object") store.overridesById = data.overridesById;
+            if (Array.isArray(data.tombstones)) store.tombstones = data.tombstones;
+            if (Array.isArray(data.custom)) store.custom = data.custom;
+            return store;
+          }
+          function saveStore() {
+            localStorage.setItem(STORAGE_KEY, JSON.stringify(state.store));
+          }
+
+          function normalizeTags(tagsText) {
+            if (!tagsText) return [];
+            return String(tagsText)
+              .split(",")
+              .map((t) => t.trim())
+              .filter(Boolean)
+              .slice(0, 12);
+          }
+
+          function normalizeLink(link) {
+            const url = normalizeUrl(link.url);
+            const id = String(link.id || "").trim() || "link-" + Math.random().toString(16).slice(2);
+            const title = String(link.title || "").trim() || domain(url) || "Link";
+            const description = String(link.description || "").trim();
+            const tags = Array.isArray(link.tags) ? link.tags.map((t) => String(t).trim()).filter(Boolean) : [];
+            const favorite = Boolean(link.favorite);
+            const createdAt = String(link.createdAt || nowIso());
+            const updatedAt = String(link.updatedAt || createdAt);
+            return { id, title, url, description, tags, favorite, createdAt, updatedAt };
+          }
+
+          const baseLinks = (() => {
+            const dataEl = document.getElementById("linksData");
+            const parsed = dataEl ? safeJsonParse(dataEl.textContent || "[]", []) : [];
+            return Array.isArray(parsed) ? parsed.map(normalizeLink) : [];
+          })();
+          const baseOrder = new Map(baseLinks.map((l, i) => [l.id, i]));
+
+          const state = {
+            store: loadStore(),
+            query: "",
+            sortKey: (el.sort && el.sort.value) || "json",
+            onlyFav: Boolean(el.onlyFav && el.onlyFav.checked),
+          };
+
+          function toTime(s) {
+            const t = Date.parse(String(s || ""));
+            return Number.isFinite(t) ? t : 0;
+          }
+          function orderKey(link) {
+            const idx = baseOrder.get(link.id);
+            if (typeof idx === "number") return idx;
+            return 1_000_000 + toTime(link.createdAt);
+          }
+
+          function getMergedLinks() {
+            const tomb = new Set(state.store.tombstones || []);
+            const overrides = state.store.overridesById || {};
+            const byId = new Map();
+            for (const base of baseLinks) {
+              if (!base || !base.id) continue;
+              if (tomb.has(base.id)) continue;
+              const o = overrides[base.id];
+              byId.set(base.id, Object.assign({}, base, o || {}));
+            }
+            for (const c of state.store.custom || []) {
+              const n = normalizeLink(c);
+              byId.set(n.id, n);
+            }
+            return Array.from(byId.values());
+          }
+
+          function compare(a, b) {
+            const key = state.sortKey || "json";
+            if (key === "json") return orderKey(a) - orderKey(b);
+            if (key === "favorite") {
+              if (a.favorite !== b.favorite) return a.favorite ? -1 : 1;
+              return orderKey(a) - orderKey(b);
+            }
+            if (key === "name") return a.title.localeCompare(b.title, "ko");
+            if (key === "domain") return domain(a.url).localeCompare(domain(b.url), "en");
+            return String(b.updatedAt).localeCompare(String(a.updatedAt));
+          }
+
+          function matches(link, q) {
+            if (!q) return true;
+            const hay = [link.title, link.url, domain(link.url), link.description || "", (link.tags || []).join(" ")]
+              .join(" ")
+              .toLowerCase();
+            return hay.includes(q);
+          }
+
+          function cardHtml(link) {
+            const d = esc(domain(link.url));
+            const t = esc(link.title);
+            const u = esc(link.url);
+            const desc = esc(link.description || "");
+            const star = link.favorite ? "star on" : "star";
+            const tags = (link.tags || []).slice(0, 8).map((x) => `<span class="tag">#${esc(x)}</span>`).join("");
+            const favTag = link.favorite ? `<span class="tag fav">★ 즐겨찾기</span>` : "";
+            const letter = esc((link.title || d || "L").trim().slice(0, 1).toUpperCase());
+            return `
+              <article class="card" data-id="${esc(link.id)}">
+                <div class="card-head">
+                  <div class="card-title">
+                    <div class="favicon" aria-hidden="true"><div class="letter">${letter}</div></div>
+                    <div class="title-wrap">
+                      <div class="title" title="${t}">${t}</div>
+                      <div class="domain" title="${d}">${d}</div>
                     </div>
                   </div>
-                  <div class="card-desc">${desc || "&nbsp;"}</div>
-                  <div class="card-actions">
-                    <a class="btn mini" href="${u}" target="_blank" rel="noopener noreferrer">열기</a>
-                  </div>
-                </article>
-              `;
-            })
-            .join("");
-          if (empty) empty.hidden = true;
-        } catch {}
-      }, 80);
+                  <button class="icon-btn" type="button" data-act="fav" title="즐겨찾기">
+                    <span class="${star}" aria-hidden="true">★</span>
+                  </button>
+                </div>
+                <div class="card-desc">${desc || "&nbsp;"}</div>
+                <div class="tags">${favTag}${tags}</div>
+                <div class="card-actions">
+                  <a class="btn mini" href="${u}" target="_blank" rel="noopener noreferrer">열기</a>
+                  <button class="btn mini" type="button" data-act="copy">URL 복사</button>
+                  <button class="btn mini" type="button" data-act="edit">편집</button>
+                  <button class="btn mini mini-danger" type="button" data-act="del">삭제</button>
+                </div>
+              </article>
+            `;
+          }
+
+          function render() {
+            const q = (state.query || "").trim().toLowerCase();
+            const all = getMergedLinks();
+            const filtered = all
+              .filter((l) => (state.onlyFav ? l.favorite : true))
+              .filter((l) => matches(l, q))
+              .sort(compare);
+            if (el.grid) el.grid.innerHTML = filtered.map(cardHtml).join("");
+            if (el.empty) el.empty.hidden = filtered.length !== 0;
+            if (el.meta) {
+              const favCount = all.filter((l) => l.favorite).length;
+              el.meta.textContent = `표시 ${filtered.length}개 · 전체 ${all.length}개 · 즐겨찾기 ${favCount}개`;
+            }
+          }
+
+          function openModal(link) {
+            if (!el.modal) return;
+            el.modal.hidden = false;
+            document.body.style.overflow = "hidden";
+            document.getElementById("modalTitle").textContent = link ? "링크 편집" : "링크 추가";
+            el.id.value = link ? link.id : "";
+            el.title.value = link ? link.title : "";
+            el.url.value = link ? link.url : "";
+            el.description.value = link ? link.description || "" : "";
+            el.tags.value = link ? (link.tags || []).join(", ") : "";
+            el.favorite.checked = link ? Boolean(link.favorite) : false;
+            setTimeout(() => el.title && el.title.focus(), 0);
+          }
+          function closeModal() {
+            if (!el.modal) return;
+            el.modal.hidden = true;
+            document.body.style.overflow = "";
+            if (el.form) el.form.reset();
+            if (el.id) el.id.value = "";
+          }
+
+          function isBaseId(id) {
+            return baseOrder.has(id);
+          }
+          function getById(id) {
+            return getMergedLinks().find((l) => l.id === id) || null;
+          }
+          function setOverride(id, patch) {
+            state.store.overridesById[id] = Object.assign({}, state.store.overridesById[id] || {}, patch);
+            saveStore();
+          }
+          function upsertCustom(link) {
+            const n = normalizeLink(link);
+            const idx = (state.store.custom || []).findIndex((c) => c && c.id === n.id);
+            if (idx >= 0) state.store.custom[idx] = n;
+            else state.store.custom.push(n);
+            saveStore();
+          }
+          function delLink(id) {
+            if (isBaseId(id)) {
+              const s = new Set(state.store.tombstones || []);
+              s.add(id);
+              state.store.tombstones = Array.from(s);
+              saveStore();
+              return;
+            }
+            state.store.custom = (state.store.custom || []).filter((c) => c && c.id !== id);
+            saveStore();
+          }
+
+          async function copy(text) {
+            try {
+              await navigator.clipboard.writeText(text);
+              toast("복사했습니다.");
+            } catch {
+              toast("복사에 실패했습니다.");
+            }
+          }
+
+          function exportJson() {
+            const data = getMergedLinks();
+            const blob = new Blob([JSON.stringify(data, null, 2)], { type: "application/json;charset=utf-8" });
+            const a = document.createElement("a");
+            a.href = URL.createObjectURL(blob);
+            a.download = `links-export-${new Date().toISOString().slice(0, 10)}.json`;
+            document.body.appendChild(a);
+            a.click();
+            setTimeout(() => {
+              URL.revokeObjectURL(a.href);
+              a.remove();
+            }, 0);
+          }
+
+          function importJsonText(text) {
+            const parsed = safeJsonParse(text, null);
+            const list = Array.isArray(parsed) ? parsed : parsed && Array.isArray(parsed.links) ? parsed.links : null;
+            if (!list) throw new Error("JSON 형식이 올바르지 않습니다.");
+            for (const item of list) {
+              if (!item) continue;
+              const n = normalizeLink(item);
+              // 충돌 방지
+              if (getById(n.id)) n.id = "import-" + Math.random().toString(16).slice(2);
+              state.store.custom.push(n);
+            }
+            saveStore();
+          }
+
+          function applyTheme(theme) {
+            const t = theme === "light" ? "light" : "dark";
+            document.documentElement.setAttribute("data-theme", t);
+            localStorage.setItem(THEME_KEY, t);
+          }
+          (function initTheme() {
+            const saved = localStorage.getItem(THEME_KEY);
+            if (saved === "light" || saved === "dark") return applyTheme(saved);
+            const prefersLight = window.matchMedia && window.matchMedia("(prefers-color-scheme: light)").matches;
+            applyTheme(prefersLight ? "light" : "dark");
+          })();
+
+          // Wire events
+          if (el.q)
+            el.q.addEventListener("input", () => {
+              state.query = el.q.value || "";
+              render();
+            });
+          if (el.sort)
+            el.sort.addEventListener("change", () => {
+              state.sortKey = el.sort.value || "json";
+              render();
+            });
+          if (el.onlyFav)
+            el.onlyFav.addEventListener("change", () => {
+              state.onlyFav = Boolean(el.onlyFav.checked);
+              render();
+            });
+          if (el.btnAdd) el.btnAdd.addEventListener("click", () => openModal(null));
+          if (el.btnClose) el.btnClose.addEventListener("click", closeModal);
+          if (el.btnCancel) el.btnCancel.addEventListener("click", closeModal);
+          if (el.modal)
+            el.modal.addEventListener("click", (e) => {
+              const close = e.target && e.target.getAttribute && e.target.getAttribute("data-close");
+              if (close) closeModal();
+            });
+          document.addEventListener("keydown", (e) => {
+            if (e.key === "Escape") closeModal();
+          });
+
+          if (el.form)
+            el.form.addEventListener("submit", (e) => {
+              e.preventDefault();
+              const id = String(el.id.value || "").trim();
+              const title = String(el.title.value || "").trim();
+              const url = normalizeUrl(el.url.value);
+              if (!title) return toast("제목을 입력하세요.");
+              if (!url) return toast("URL을 입력하세요.");
+              const description = String(el.description.value || "").trim();
+              const tags = normalizeTags(el.tags.value);
+              const favorite = Boolean(el.favorite.checked);
+              const patch = { title, url, description, tags, favorite, updatedAt: nowIso() };
+              if (id) {
+                const cur = getById(id);
+                if (!cur) return toast("편집 대상이 없습니다.");
+                if (isBaseId(id)) setOverride(id, patch);
+                else upsertCustom(Object.assign({}, cur, patch));
+                toast("저장했습니다.");
+              } else {
+                upsertCustom({
+                  id: "custom-" + Date.now() + "-" + Math.random().toString(16).slice(2),
+                  title,
+                  url,
+                  description,
+                  tags,
+                  favorite,
+                  createdAt: nowIso(),
+                  updatedAt: nowIso(),
+                });
+                toast("추가했습니다.");
+              }
+              closeModal();
+              render();
+            });
+
+          if (el.grid)
+            el.grid.addEventListener("click", (e) => {
+              const btn = e.target.closest("[data-act]");
+              if (!btn) return;
+              const card = e.target.closest(".card");
+              if (!card) return;
+              const id = card.getAttribute("data-id");
+              const act = btn.getAttribute("data-act");
+              const link = id ? getById(id) : null;
+              if (!link) return;
+              if (act === "fav") {
+                const next = !link.favorite;
+                if (isBaseId(id)) setOverride(id, { favorite: next, updatedAt: nowIso() });
+                else upsertCustom(Object.assign({}, link, { favorite: next, updatedAt: nowIso() }));
+                render();
+              } else if (act === "copy") {
+                copy(link.url);
+              } else if (act === "edit") {
+                openModal(link);
+              } else if (act === "del") {
+                if (confirm(`삭제할까요?\n\n- ${link.title}`)) {
+                  delLink(id);
+                  render();
+                }
+              }
+            });
+
+          if (el.btnExport) el.btnExport.addEventListener("click", exportJson);
+          if (el.btnImport)
+            el.btnImport.addEventListener("click", () => {
+              if (el.file) el.file.click();
+            });
+          if (el.file)
+            el.file.addEventListener("change", async () => {
+              const f = el.file.files && el.file.files[0];
+              el.file.value = "";
+              if (!f) return;
+              try {
+                importJsonText(await f.text());
+                toast("가져오기 완료");
+                render();
+              } catch (err) {
+                toast(String(err && err.message ? err.message : "가져오기 실패"));
+              }
+            });
+
+          if (el.btnTheme)
+            el.btnTheme.addEventListener("click", () => {
+              const cur = document.documentElement.getAttribute("data-theme") || "dark";
+              applyTheme(cur === "dark" ? "light" : "dark");
+            });
+
+          render();
+          toast("스크립트 로딩 문제로 폴백 모드로 실행 중입니다.");
+        }, 200);
+      })();
     </script>
 
     <noscript>
diff --git a/script.js b/script.js
index ffb8dbf..7c5a79c 100644
--- a/script.js
+++ b/script.js
@@ -1,6 +1,8 @@
 (() => {
   "use strict";
 
+  // If index.html inline fallback already booted, do nothing.
+  if (globalThis.__LINKS_APP_BOOTED__) return;
   // Mark boot so index.html fallback won't run
   globalThis.__LINKS_APP_BOOTED__ = true;