diff --git a/web/static/css/custom.css b/web/static/css/custom.css
index 02bc28e7..5e203751 100644
--- a/web/static/css/custom.css
+++ b/web/static/css/custom.css
@@ -474,13 +474,15 @@ footer {
     display: none;
 }
 
-/* Global Operation Banner - centered within content-wrapper */
+/* Global Operation Banner - centered within content-wrapper.
+   z-index 100: above page content, below the theme toggle (101), the sidebar (160)
+   and the mobile header (200), so it can never cover the navigation (#216). */
 #global-operation-banner {
     position: absolute;
     top: 0;
     left: 50%;
     transform: translateX(-50%);
-    z-index: 9999;
+    z-index: 100;
     pointer-events: none;
     display: flex;
     justify-content: center;
@@ -494,6 +496,28 @@ footer {
     pointer-events: auto;
 }
 
+/* Fit mode (#216): the fit check in base.html adds .di-flow when the centred pill
+   would collide with the page title, the action buttons or the theme toggle (narrow
+   windows, high zoom, phones). The banner then becomes a full-width row of the page
+   header, ordered after the buttons, and moves back up as soon as there is room. */
+.page-header > #global-operation-banner.di-flow {
+    position: relative;
+    top: auto;
+    left: auto;
+    right: auto;
+    transform: none;
+    order: 1;
+    flex: 1 1 100%;
+    min-height: 38px;
+    align-items: flex-start;
+}
+
+/* Dashboard/Maintenance start with a light "Updated ... / Refresh" row instead of a
+   card, so in fit mode the space below the pill can be a bit tighter. */
+.content-wrapper:has(#global-operation-banner.di-flow) .stats-header {
+    margin-top: -0.75rem;
+}
+
 
 /* Foreground/background tokens for the pill — dark by default.
    Text-legibility tiers (--di-t*) exist because opacity-based text
@@ -1357,6 +1381,18 @@ footer {
     border-bottom-color: rgba(0,0,0,0.3);
 }
 
+/* Fit mode: the expanded pill stays an overlay on top of the page content */
+#global-operation-banner.di-flow[data-di-expanded="tier2"] .di-pill,
+#global-operation-banner.di-flow[data-di-expanded="tier3"] .di-pill,
+#global-operation-banner.di-flow .di-pill.di-expanded {
+    position: absolute;
+    top: 0;
+    left: 50%;
+    translate: -50% 0;
+    width: max-content;
+    max-width: min(620px, calc(100vw - 2rem));
+}
+
 /* ── Mobile responsive ───────────────────────────────── */
 @media (max-width: 768px) {
     #global-operation-banner {
@@ -1376,6 +1412,24 @@ footer {
         min-width: auto;
     }
 
+    /* The header is a column here: stretch the banner to the full width (the row
+       layout's flex-basis does not apply) so the pill and its overlay get a width. */
+    .page-header > #global-operation-banner.di-flow {
+        flex: 0 0 auto;
+        align-self: stretch;
+    }
+
+    #global-operation-banner.di-flow[data-di-expanded="tier2"] .di-pill,
+    #global-operation-banner.di-flow[data-di-expanded="tier3"] .di-pill,
+    #global-operation-banner.di-flow .di-pill.di-expanded {
+        left: 0;
+        right: 0;
+        translate: none;
+        width: auto;
+        min-width: 0;
+        max-width: none;
+    }
+
     .di-pill__detail {
         max-height: 150px;
     }
diff --git a/web/templates/base.html b/web/templates/base.html
index 8561e1ed..8bfc7e7c 100644
--- a/web/templates/base.html
+++ b/web/templates/base.html
@@ -156,6 +156,71 @@
 
                 {% block content %}{% endblock %}
 
+                <script>
+                    // Operation pill placement (#216). The pill stays centred on top of the page
+                    // (Dynamic-Island style) as long as it does not collide with the page title,
+                    // the action buttons or the theme toggle. If it would, it gets .di-flow and
+                    // becomes a full-width row of the header, below the buttons. Measured with
+                    // .di-flow removed, so it moves back up as soon as there is room again.
+                    (function () {
+                        var banner = document.getElementById('global-operation-banner');
+                        var header = document.querySelector('.content-wrapper > .page-header');
+                        if (!banner || !header) return;
+                        // Child of the header so the fit mode can place it in the header flow;
+                        // the default state is absolutely positioned and does not affect the layout.
+                        var title = header.querySelector(':scope > .page-title');
+                        header.insertBefore(banner, title ? title.nextSibling : header.firstChild);
+
+                        function collides(a, b, gap) {
+                            if (!b || !b.width || !b.height) return false;
+                            return a.left < b.right + gap && a.right + gap > b.left &&
+                                   a.top < b.bottom && a.bottom > b.top;
+                        }
+
+                        function fit() {
+                            var state = banner.getAttribute('data-di-expanded');
+                            if (state === 'tier2' || state === 'tier3') return; // expanded overlay: keep mode
+                            if (!banner.querySelector('.di-pill')) return;
+                            var inFlow = banner.classList.contains('di-flow');
+                            if (inFlow) banner.classList.remove('di-flow');
+                            var rect = banner.getBoundingClientRect();
+                            var gap = inFlow ? 40 : 16; // hysteresis: no flip-flopping at the edge
+                            var hit = [
+                                header.querySelector(':scope > .page-title'),
+                                header.querySelector(':scope > .action-buttons'),
+                                document.querySelector('.top-controls')
+                            ].some(function (el) {
+                                return el && collides(rect, el.getBoundingClientRect(), gap);
+                            });
+                            if (hit) banner.classList.add('di-flow');
+                        }
+
+                        // Content swaps are handled synchronously (microtask, before the next paint),
+                        // so the pill never flashes in the wrong place. Expand/collapse animations
+                        // are re-checked once they are done.
+                        var slow = null;
+                        if (window.ResizeObserver) {
+                            new ResizeObserver(function () { requestAnimationFrame(fit); }).observe(header);
+                        } else {
+                            window.addEventListener('resize', fit);
+                        }
+                        // Banner content is replaced by htmx and by diTriggerRun() (innerHTML)
+                        new MutationObserver(function (list) {
+                            if (list.some(function (m) { return m.type === 'childList'; })) fit();
+                            if (list.some(function (m) { return m.type === 'attributes'; })) {
+                                clearTimeout(slow);
+                                slow = setTimeout(fit, 450);
+                            }
+                        }).observe(banner, {
+                            childList: true, // direct children only: the pill itself being replaced
+                            attributes: true, attributeFilter: ['data-di-expanded']
+                        });
+                        if (document.fonts && document.fonts.ready) document.fonts.ready.then(fit);
+                        window.addEventListener('load', fit);
+                        fit();
+                    })();
+                </script>
+
                 <footer>
                     PlexCache-D Web UI <span class="version">v{{ web_version }}</span>
                 </footer>