diff --git a/viz/index.html b/viz/index.html
index ad7130d..b751040 100644
--- a/viz/index.html
+++ b/viz/index.html
@@ -2566,6 +2566,83 @@
     if (typeof p.bpm === "number") godtime.bpm = clamp(p.bpm, 40, 180);
     layoutDirty = true;
   }
+
+  // ---- zero mode — dimension zero -------------------------------------------
+  // The calm front door: not a muted world (moods do that) but an EMPTY one — no
+  // cables, nothing sounding — that you build by hand. It is the SAME matrix
+  // (routesArr/tweaks/synth), just started from nothing; leaving zero restores
+  // the world you had. Client-local, like moods — the hub/other users untouched.
+  let zeroMode = false;
+  function enterZero() {
+    if (!zeroMode) {                       // snapshot what you had, so exiting can restore it
+      try { localStorage.setItem("gs_prezero", JSON.stringify(serializePatch())); } catch (e) {}
+    }
+    clientMatrix = true;                   // own the matrix so the hub can't re-populate the cables
+    loadPatch({ routes: [], tweaks: {}, seqs: {} });   // empty the field
+    zeroMode = true;
+    try { localStorage.setItem("gs_mood", "0 zero"); } catch (e) {}
+    eventTicker.unshift({ text: "🌱 zero — the field is empty. build your own instrument: right-click a source → patch to → a voice, then press ♪", tAdded: now(), src: "sys" });
+    layoutDirty = true;
+  }
+  function exitZeroToMood(name) {          // leave zero back into the full world, then a mood
+    if (zeroMode) {
+      zeroMode = false;
+      try { const pz = localStorage.getItem("gs_prezero"); if (pz) loadPatch(JSON.parse(pz)); } catch (e) {}
+    }
+    applyMood(name);
+  }
+
+  // The three doors, shown once on a first-ever visit (replaces the silent drop
+  // into first light). Backdrop/esc = first light, the gentle default.
+  function showFirstVisitCard() {
+    if (document.getElementById("firstcard")) return;
+    const wrap = document.createElement("div");
+    wrap.id = "firstcard";
+    Object.assign(wrap.style, { position: "fixed", inset: "0", zIndex: "70", display: "flex",
+      alignItems: "center", justifyContent: "center", background: "rgba(6,10,20,0.72)",
+      backdropFilter: "blur(8px)", WebkitBackdropFilter: "blur(8px)" });
+    const card = document.createElement("div");
+    Object.assign(card.style, { maxWidth: "640px", width: "88%", textAlign: "center",
+      color: "#d6e2f4", fontFamily: "inherit" });
+    const h = document.createElement("div");
+    h.textContent = "one world, three doors";
+    Object.assign(h.style, { fontWeight: "800", fontSize: "clamp(22px,4vw,32px)", letterSpacing: "2px", marginBottom: "6px" });
+    const sub = document.createElement("div");
+    sub.textContent = "the planet is already playing. choose how you meet it.";
+    Object.assign(sub.style, { color: "rgba(165,185,218,0.75)", fontStyle: "italic", marginBottom: "26px", fontSize: "14px" });
+    card.appendChild(h); card.appendChild(sub);
+    const row = document.createElement("div");
+    Object.assign(row.style, { display: "flex", gap: "14px", flexWrap: "wrap", justifyContent: "center" });
+    const doors = [
+      ["🌱", "start from zero", "an empty field. build the instrument yourself, one cable at a time.", () => enterZero()],
+      ["🌅", "first light", "a gentle arrangement — a bass line, soft hats, a small melody. ease in.", () => applyMood("first light")],
+      ["⛈", "the full storm", "every one of the world's hands on it at once. the factory instrument.", () => applyMood("the full storm")],
+    ];
+    for (const [emoji, title, desc, act] of doors) {
+      const b = document.createElement("div");
+      Object.assign(b.style, { flex: "1 1 170px", minWidth: "160px", maxWidth: "200px", cursor: "pointer",
+        padding: "20px 16px", borderRadius: "16px", background: "rgba(20,28,44,0.7)",
+        border: "1px solid rgba(120,150,200,0.28)", transition: "transform .12s, border-color .12s" });
+      b.onmouseenter = () => { b.style.transform = "translateY(-3px)"; b.style.borderColor = "rgba(150,200,255,0.7)"; };
+      b.onmouseleave = () => { b.style.transform = ""; b.style.borderColor = "rgba(120,150,200,0.28)"; };
+      b.innerHTML = '<div style="font-size:34px;margin-bottom:8px">' + emoji + '</div>'
+        + '<div style="font-weight:700;color:#eaf1ff;margin-bottom:6px">' + title + '</div>'
+        + '<div style="font-size:12px;color:rgba(180,195,225,0.75);line-height:1.5">' + desc + '</div>';
+      b.onclick = () => { wrap.remove(); document.removeEventListener("keydown", onEsc, true); act(); };
+      row.appendChild(b);
+    }
+    card.appendChild(row);
+    const foot = document.createElement("div");
+    foot.textContent = "you can switch any time — right-click the sky → 🌗 mood";
+    Object.assign(foot.style, { marginTop: "22px", fontSize: "11px", color: "rgba(150,170,205,0.55)" });
+    card.appendChild(foot);
+    wrap.appendChild(card);
+    const onEsc = (e) => { if (e.key === "Escape") { wrap.remove(); document.removeEventListener("keydown", onEsc, true); applyMood("first light"); } };
+    wrap.onclick = (e) => { if (e.target === wrap) { wrap.remove(); document.removeEventListener("keydown", onEsc, true); applyMood("first light"); } };
+    document.addEventListener("keydown", onEsc, true);
+    document.body.appendChild(wrap);
+  }
+
   function makeGroupLocal(name, members) {
     if (!name || !members || !members.length) return;
     groupsInfo[name] = { label: name, members: members.slice() };
@@ -2841,10 +2918,13 @@
           try { firstEver = !localStorage.getItem("gs_seen"); } catch (e) {}
           try { saved = localStorage.getItem("gs_mood") || "first light"; } catch (e) {}
           setTimeout(() => {
-            applyMood(saved);
             if (firstEver) {
               try { localStorage.setItem("gs_seen", "1"); } catch (e) {}
-              eventTicker.unshift({ text: "🌅 first light — a gentle arrangement to start you off. right-click the sky → 🌗 mood for more (or the full storm when you're ready)", tAdded: now(), src: "sys" });
+              showFirstVisitCard();          // three doors: zero / first light / storm
+            } else if (saved === "0 zero") {
+              enterZero();                   // a returning zero-builder comes back to zero
+            } else {
+              applyMood(saved);
             }
           }, 900);
         }
@@ -5580,9 +5660,13 @@
       ctxItem(arr.open ? "close tracks" : "🎛 tracks — arrange clips",
         () => { arr.open ? closeArranger() : openArranger(); }, "T");
       const moodSub = ctxSub("🌗 mood — how much world");
+      const z0 = document.createElement("div"); z0.className = "it";
+      z0.textContent = zeroMode ? "0 zero — you're building it (a mood leaves)" : "0 zero — build from nothing";
+      z0.onclick = () => { enterZero(); closeCtx(); };
+      moodSub.appendChild(z0);
       for (const mn of Object.keys(MOODS)) {
         const it2 = document.createElement("div"); it2.className = "it"; it2.textContent = mn;
-        it2.onclick = () => { applyMood(mn); closeCtx(); };
+        it2.onclick = () => { zeroMode ? exitZeroToMood(mn) : applyMood(mn); closeCtx(); };
         moodSub.appendChild(it2);
       }
       if (mindChakra) ctxItem("step out of " + mindChakra.label, () => exitMind(), "esc");
@@ -6174,9 +6258,10 @@
     nudgeDown: { label: "lower the level of…", targeted: true, run: (k) => { const t = tw(k); t.gain = clamp((t.gain != null ? t.gain : 1) - 0.08, 0, 2); } },
     muteKey:   { label: "mute / unmute…", targeted: true, run: (k) => toggleMuteLocal(k) },
     soloKeyA:  { label: "solo…", targeted: true, run: (k) => { soloKey = soloKey === k ? null : k; } },
+    zero:      { label: "zero — build from nothing", run: () => { zeroMode ? exitZeroToMood("first light") : enterZero(); } },
   };
   const DEFAULT_KEYS = { F1: { a: "grimoire" }, F2: { a: "play" }, F3: { a: "chakraView" }, F4: { a: "skinNext" },
-    F5: { a: "moodCycle" }, F6: { a: "tracks" }, F7: { a: "perform" }, F8: { a: "godLock" }, F9: { a: "earthEcho" }, F10: { a: "stage" } };
+    F5: { a: "moodCycle" }, F6: { a: "tracks" }, F7: { a: "perform" }, F8: { a: "godLock" }, F9: { a: "earthEcho" }, F10: { a: "stage" }, F11: { a: "zero" } };
   let keymap = {};
   try { keymap = JSON.parse(localStorage.getItem("gs_keys")) || {}; } catch (e) {}
   if (!Object.keys(keymap).length) keymap = JSON.parse(JSON.stringify(DEFAULT_KEYS));