diff --git a/web/app.js b/web/app.js
index 5bff2e8..a34351d 100644
--- a/web/app.js
+++ b/web/app.js
@@ -1451,6 +1451,14 @@
       return;
     }
 
+    if (ev.key === 'Escape' && $('main').classList.contains('focus-peek')) {
+      exitFocusPeek();
+      state.selectedIndex = -1;
+      renderEntityList();
+      renderDetailPane();
+      return;
+    }
+
     const sel = state.entities[state.selectedIndex];
 
     switch (ev.key) {
@@ -1534,6 +1542,17 @@
 
   function toggleZen() {
     const m = $('main');
+
+    if (m.classList.contains('focus-peek')) {
+      exitFocusPeek();
+      return;
+    }
+
+    if (state.selectedIndex >= 0) {
+      m.classList.add('focus-peek');
+      return;
+    }
+
     const isZen = m.classList.contains('hide-rail') && m.classList.contains('hide-peek');
     if (isZen) {
       m.classList.remove('hide-rail', 'hide-peek');
@@ -1546,12 +1565,72 @@
     }
   }
 
+  function exitFocusPeek() {
+    $('main').classList.remove('focus-peek');
+  }
+
   (function restorePanels() {
     const m = $('main');
     if (localStorage.getItem('nib:hide-rail')) m.classList.add('hide-rail');
     if (localStorage.getItem('nib:hide-peek')) m.classList.add('hide-peek');
+    const railW = localStorage.getItem('nib:rail-w');
+    const peekW = localStorage.getItem('nib:peek-w');
+    if (railW) m.style.setProperty('--rail-w', railW + 'px');
+    if (peekW) m.style.setProperty('--peek-w', peekW + 'px');
   })();
 
+  // ========== Resize handles ==========
+
+  $$('.resize-handle').forEach(handle => {
+    let startX, startW, panel;
+
+    handle.addEventListener('mousedown', (ev) => {
+      ev.preventDefault();
+      panel = handle.dataset.panel;
+      startX = ev.clientX;
+      const m = $('main');
+      m.classList.add('resizing');
+      handle.classList.add('active');
+
+      if (panel === 'rail') {
+        startW = $('#tag-rail').offsetWidth;
+      } else {
+        startW = $('#detail-pane').offsetWidth;
+      }
+
+      document.addEventListener('mousemove', onMove);
+      document.addEventListener('mouseup', onUp);
+    });
+
+    function onMove(ev) {
+      const m = $('main');
+      const dx = ev.clientX - startX;
+      let newW;
+
+      if (panel === 'rail') {
+        newW = Math.max(120, Math.min(360, startW + dx));
+        m.style.setProperty('--rail-w', newW + 'px');
+      } else {
+        newW = Math.max(250, Math.min(700, startW - dx));
+        m.style.setProperty('--peek-w', newW + 'px');
+      }
+    }
+
+    function onUp() {
+      const m = $('main');
+      m.classList.remove('resizing');
+      handle.classList.remove('active');
+      document.removeEventListener('mousemove', onMove);
+      document.removeEventListener('mouseup', onUp);
+
+      if (panel === 'rail') {
+        localStorage.setItem('nib:rail-w', $('#tag-rail').offsetWidth);
+      } else {
+        localStorage.setItem('nib:peek-w', $('#detail-pane').offsetWidth);
+      }
+    }
+  });
+
   function scrollSelectedIntoView() {
     const el = $(`.entity-item[data-index="${state.selectedIndex}"], .card-row[data-index="${state.selectedIndex}"]`);
     if (el) el.scrollIntoView({ block: 'nearest' });
diff --git a/web/index.html b/web/index.html
index cc63663..60990d2 100644
--- a/web/index.html
+++ b/web/index.html
@@ -24,11 +24,13 @@
         </header>
         <main>
             <aside id="tag-rail"></aside>
+            <div class="resize-handle" data-panel="rail"></div>
             <section id="entity-panel">
                 <div id="month-nav"></div>
                 <div id="entity-list"></div>
                 <div id="capture-bar"></div>
             </section>
+            <div class="resize-handle" data-panel="peek"></div>
             <aside id="detail-pane">
                 <div class="detail-empty">select an entity</div>
             </aside>
diff --git a/web/style.css b/web/style.css
index eb6f779..2e3863a 100644
--- a/web/style.css
+++ b/web/style.css
@@ -177,17 +177,39 @@ nav { display: flex; gap: 2px; }
 /* ── MAIN LAYOUT ────────────────────────────────────── */
 main {
     display: grid;
-    grid-template-columns: 192px 1fr 400px;
+    grid-template-columns: var(--rail-w, 192px) 4px 1fr 4px var(--peek-w, 400px);
     overflow: hidden;
-    transition: grid-template-columns var(--t-base);
 }
 
-main.hide-rail { grid-template-columns: 0px 1fr 400px; }
-main.hide-peek { grid-template-columns: 192px 1fr 0px; }
-main.hide-rail.hide-peek { grid-template-columns: 0px 1fr 0px; }
+main.resizing { transition: none; }
+main:not(.resizing) { transition: grid-template-columns var(--t-base); }
 
-main.hide-rail #tag-rail { overflow: hidden; border-right: none; }
-main.hide-peek #detail-pane { overflow: hidden; border-left: none; }
+main.hide-rail { grid-template-columns: 0px 0px 1fr 4px var(--peek-w, 400px); }
+main.hide-peek { grid-template-columns: var(--rail-w, 192px) 4px 1fr 0px 0px; }
+main.hide-rail.hide-peek { grid-template-columns: 0px 0px 1fr 0px 0px; }
+
+main.hide-rail #tag-rail { overflow: hidden; border-right: none; min-width: 0; }
+main.hide-peek #detail-pane { overflow: hidden; border-left: none; min-width: 0; }
+main.hide-rail .resize-handle[data-panel="rail"] { visibility: hidden; }
+main.hide-peek .resize-handle[data-panel="peek"] { visibility: hidden; }
+
+main.focus-peek { grid-template-columns: 0px 0px 0px 0px 1fr; }
+main.focus-peek #tag-rail { overflow: hidden; border-right: none; min-width: 0; }
+main.focus-peek #entity-panel { overflow: hidden; min-width: 0; }
+main.focus-peek .resize-handle { visibility: hidden; }
+
+.resize-handle {
+    cursor: col-resize;
+    background: transparent;
+    transition: background var(--t-fast);
+    z-index: 10;
+}
+
+.resize-handle:hover,
+.resize-handle.active {
+    background: var(--accent);
+    opacity: .4;
+}
 
 /* ── TAG RAIL ───────────────────────────────────────── */
 #tag-rail {