GM screen v3: true page-per-section tabbed navigation

Replace the accordion with a pager: the sidebar is now a tab list and
exactly one section renders at a time as its own page - no more single
long scroll. Adds Prev/Next buttons labelled with the neighbouring
page names, arrow-key paging, last-open-page persistence, and search
that dims non-matching tabs with Enter jumping to the first match
(Escape clears). All trackers, clue ticks and notes unchanged.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

documentation/false-alarm-gm-screen.html

@@ -33,20 +33,21 @@
     border-radius:5px;padding:6px 4px;font-size:11px;cursor:pointer}
   .navbtns button:hover{color:var(--ink);border-color:var(--olive)}
 
-  /* ---------- main / accordion ---------- */
-  main{flex:1;max-width:920px;padding:26px 40px 30vh}
-  section{margin-bottom:10px;scroll-margin-top:14px;border:1px solid var(--edge);border-radius:9px;
-    background:var(--panel);overflow:hidden}
-  .sec-head{display:flex;align-items:center;gap:12px;padding:13px 16px;cursor:pointer;user-select:none}
-  .sec-head:hover{background:var(--panel2)}
-  .sec-head .chev{flex:0 0 auto;width:22px;height:22px;border-radius:5px;border:1px solid var(--edge);
-    display:grid;place-items:center;color:var(--olive-b);font-size:12px;transition:transform .18s}
-  section.open .sec-head .chev{transform:rotate(90deg)}
-  .sec-head h2{font-size:16.5px;letter-spacing:1.4px;text-transform:uppercase;flex:1}
+  /* ---------- main / pager: exactly one section visible ---------- */
+  main{flex:1;max-width:940px;padding:22px 40px 60px}
+  section{display:none;border:1px solid var(--edge);border-radius:9px;background:var(--panel);overflow:hidden}
+  section.active{display:block}
+  .sec-head{display:flex;align-items:center;gap:12px;padding:14px 18px;user-select:none}
+  .sec-head .chev{display:none}
+  .sec-head h2{font-size:17.5px;letter-spacing:1.4px;text-transform:uppercase;flex:1}
   .sec-head .tag{font-size:11px;letter-spacing:1px;color:var(--mut);font-weight:400;text-transform:none;display:block}
   .sec-head .accent{width:4px;align-self:stretch;border-radius:2px;background:var(--olive);flex:0 0 4px}
-  .sec-body{display:none;padding:4px 20px 20px;border-top:1px solid var(--hair)}
-  section.open .sec-body{display:block}
+  .sec-body{display:block;padding:4px 22px 22px;border-top:1px solid var(--hair)}
+  .pager{display:flex;justify-content:space-between;gap:10px;margin-top:14px}
+  .pager button{background:var(--panel);border:1px solid var(--edge);color:var(--mut);border-radius:7px;
+    padding:9px 16px;font-size:13px;cursor:pointer}
+  .pager button:hover:not(:disabled){color:var(--olive-b);border-color:var(--olive)}
+  .pager button:disabled{opacity:.3;cursor:default}
 
   h3{font-size:13.5px;color:var(--olive-b);letter-spacing:1px;margin:18px 0 6px;text-transform:uppercase}
   h4{font-size:13px;color:var(--gold);margin:12px 0 4px}
@@ -119,8 +120,6 @@
   </div>
   <input id="search" type="search" placeholder="Search everything…  ( / )">
   <div class="navbtns">
-    <button onclick="openAll(true)">Open all</button>
-    <button onclick="openAll(false)">Close all</button>
     <button onclick="expNotes()">Export</button>
     <button onclick="impNotes()">Import</button>
     <button onclick="resetAll()">Reset</button>
@@ -661,25 +660,45 @@
 (function(){
   const LS = k => "fa-gm-" + k;
 
-  /* ---------- accordion ---------- */
+  /* ---------- pager: one page at a time ---------- */
   const secs = [...document.querySelectorAll("main section")];
-  function setOpen(sec, open, save = true) {
-    sec.classList.toggle("open", open);
-    if (save) localStorage.setItem(LS("open-" + sec.id), open ? "1" : "0");
-  }
-  secs.forEach(sec => {
-    sec.querySelector(".sec-head").addEventListener("click", () => setOpen(sec, !sec.classList.contains("open")));
-    if (localStorage.getItem(LS("open-" + sec.id)) === "1") setOpen(sec, true, false);
-  });
-  window.openAll = (v) => secs.forEach(s => setOpen(s, v));
+  const order = secs.map(s => s.id);
+  const navLinks = [...document.querySelectorAll("nav a[data-go]")];
 
-  /* nav: open + scroll */
-  document.querySelectorAll("nav a[data-go]").forEach(a => {
-    a.addEventListener("click", () => {
-      const sec = document.getElementById(a.dataset.go);
-      setOpen(sec, true);
-      sec.scrollIntoView({ behavior: "smooth", block: "start" });
-    });
+  // Prev / Next controls (rendered below whichever page is active)
+  const pager = document.createElement("div");
+  pager.className = "pager";
+  pager.innerHTML = `<button id="pgPrev">◀ Previous</button><button id="pgNext">Next ▶</button>`;
+  document.getElementById("main").appendChild(pager);
+
+  function showPage(id, save = true) {
+    if (!order.includes(id)) id = order[0];
+    secs.forEach(s => s.classList.toggle("active", s.id === id));
+    navLinks.forEach(a => a.classList.toggle("on", a.dataset.go === id));
+    const i = order.indexOf(id);
+    const prev = pager.querySelector("#pgPrev"), next = pager.querySelector("#pgNext");
+    prev.disabled = i === 0; next.disabled = i === order.length - 1;
+    prev.textContent = i > 0 ? "◀ " + (document.querySelector(`nav a[data-go="${order[i-1]}"]`)?.textContent ?? "Previous") : "◀ Previous";
+    next.textContent = i < order.length - 1 ? (document.querySelector(`nav a[data-go="${order[i+1]}"]`)?.textContent ?? "Next") + " ▶" : "Next ▶";
+    window.scrollTo({ top: 0 });
+    if (save) localStorage.setItem(LS("page"), id);
+  }
+  pager.querySelector("#pgPrev").addEventListener("click", () => {
+    const i = order.indexOf(order.find(id => document.getElementById(id).classList.contains("active")));
+    if (i > 0) showPage(order[i - 1]);
+  });
+  pager.querySelector("#pgNext").addEventListener("click", () => {
+    const i = order.indexOf(order.find(id => document.getElementById(id).classList.contains("active")));
+    if (i < order.length - 1) showPage(order[i + 1]);
+  });
+  navLinks.forEach(a => a.addEventListener("click", () => showPage(a.dataset.go)));
+  showPage(localStorage.getItem(LS("page")) || order[0], false);
+
+  // keyboard: ← / → to page when not typing
+  document.addEventListener("keydown", e => {
+    if (e.target.isContentEditable || ["INPUT","TEXTAREA"].includes(e.target.tagName)) return;
+    if (e.key === "ArrowLeft") pager.querySelector("#pgPrev").click();
+    if (e.key === "ArrowRight") pager.querySelector("#pgNext").click();
   });
 
   /* ---------- notes ---------- */
@@ -775,30 +794,27 @@
     tab.appendChild(tr);
   }
 
-  /* ---------- nav highlight ---------- */
-  const links = [...document.querySelectorAll("nav a[data-go]")];
-  const onScroll = () => {
-    let i = secs.findLastIndex(s => s.getBoundingClientRect().top < 120);
-    links.forEach(a => a.classList.toggle("on", a.dataset.go === (secs[Math.max(0, i)] || {}).id));
-  };
-  document.addEventListener("scroll", onScroll, { passive: true }); onScroll();
-
-  /* ---------- search (opens matches) ---------- */
+  /* ---------- search: filters the tab list, Enter jumps to first match ---------- */
   const box = document.getElementById("search");
   document.addEventListener("keydown", e => {
     if (e.key === "/" && document.activeElement !== box && !e.target.isContentEditable && e.target.tagName !== "INPUT") {
       e.preventDefault(); box.focus();
     }
   });
-  box.addEventListener("input", () => {
+  const matchIds = () => {
     const q = box.value.trim().toLowerCase();
-    secs.forEach(s => {
-      const hit = !q || s.textContent.toLowerCase().includes(q);
-      s.style.display = hit ? "" : "none";
-      if (q && hit) setOpen(s, true, false);
-      links.find(a => a.dataset.go === s.id)?.style.setProperty("opacity", hit ? "1" : ".3");
-    });
-    if (!q) secs.forEach(s => setOpen(s, localStorage.getItem(LS("open-" + s.id)) === "1", false));
+    return q ? secs.filter(s => s.textContent.toLowerCase().includes(q)).map(s => s.id) : order;
+  };
+  box.addEventListener("input", () => {
+    const hits = matchIds();
+    navLinks.forEach(a => a.style.setProperty("opacity", hits.includes(a.dataset.go) ? "1" : ".28"));
+  });
+  box.addEventListener("keydown", e => {
+    if (e.key === "Enter") {
+      const hits = matchIds();
+      if (hits.length) { showPage(hits[0]); box.blur(); }
+    }
+    if (e.key === "Escape") { box.value = ""; box.dispatchEvent(new Event("input")); box.blur(); }
   });
 
   /* ---------- export / import / reset ---------- */