diff --git a/vault-custom.js b/vault-custom.js
index 9217c2f..9874426 100644
--- a/vault-custom.js
+++ b/vault-custom.js
@@ -7,8 +7,14 @@
  *   1. Current-page highlighting in 3D Graph
  *   2. Click-to-navigate on 3D Graph nodes (Three.js raycasting)
  *   3. Responsive layout (graph collapses below 1024px, tree below 768px)
+ *   4. URL-based navigation (?file=<path>)
  *
  * Design notes: see docs/ARCHITECTURE.md
+ *
+ * IMPORTANT: This script runs AFTER obv's main script (which sets up the
+ * layout). So our responsiveLayout() needs to apply classes/styles AFTER
+ * obv's setup, and our CSS must win the specificity battle against obv's
+ * inline styles + media queries.
  */
 (function() {
     'use strict';
@@ -18,60 +24,239 @@
     const HermesCustom = window.HermesCustom;
 
     // ============================================================
-    // 1. Current-page highlighting
+    // Configuration
+    // ============================================================
+
+    const BREAKPOINTS = {
+        mobile:  768,   // <768px
+        tablet:  1024,  // 768-1023px
+    };
+
+    // ============================================================
+    // 1. CSS injection — high specificity to win against obv
     // ============================================================
 
     /**
-     * Determine which file is currently being viewed.
-     * Uses URL ?file=<path> parameter, or falls back to extracting from the
-     * page content (the last file fetched via loadFile).
+     * Inject responsive CSS into <head> as a stylesheet (not <style>), so
+     * the cascade is well-defined. We use:
+     *   - High specificity selectors (extra class chains)
+     *   - !important on critical layout properties
+     *   - CSS variables that we toggle via JS
+     *
+     * Strategy: we add a class `hermes-rc` (hermes responsive container) to
+     * the .vault-app element. All our CSS rules start with `.vault-app.hermes-rc`
+     * to beat obv's `.vault-app` selectors.
      */
+    HermesCustom.injectResponsiveCSS = function() {
+        if (document.getElementById('hermes-custom-css')) return;
+
+        // Wait until <head> exists
+        const head = document.head || document.getElementsByTagName('head')[0];
+        if (!head) {
+            setTimeout(HermesCustom.injectResponsiveCSS, 10);
+            return;
+        }
+
+        const style = document.createElement('style');
+        style.id = 'hermes-custom-css';
+        style.textContent = `
+/* === Hermes Custom: always-applied base (no media query) === */
+.vault-app.hermes-rc {
+    box-sizing: border-box !important;
+    width: 100% !important;
+    max-width: 100vw !important;
+    overflow-x: hidden !important;   /* prevent horizontal scroll on mobile */
+}
+.vault-app.hermes-rc .vault-content {
+    overflow-x: hidden !important;   /* content scrolls vertically only */
+    overflow-y: auto !important;
+    max-width: 100% !important;
+    word-wrap: break-word !important; /* long URLs/codes don't overflow */
+    overflow-wrap: break-word !important;
+}
+.vault-app.hermes-rc .vault-sidebar {
+    overflow-x: hidden !important;
+    overflow-y: auto !important;
+    max-width: 280px !important;
+}
+.vault-app.hermes-rc .vault-graph {
+    overflow: hidden !important;
+    position: relative !important;
+}
+
+/* === Mobile (<768px) === */
+.vault-app.hermes-rc.hermes-mobile {
+    grid-template-columns: 1fr !important;
+    grid-template-rows: 48px 1fr !important;
+}
+.vault-app.hermes-rc.hermes-mobile .vault-sidebar {
+    position: fixed !important;
+    top: 48px !important;
+    left: 0 !important;
+    bottom: 0 !important;
+    width: 280px !important;
+    max-width: 85vw !important;
+    transform: translateX(-100%) !important;
+    transition: transform 0.2s ease !important;
+    z-index: 1000 !important;
+    background: var(--bg-secondary) !important;
+    border-right: 1px solid var(--border) !important;
+    display: block !important;
+}
+.vault-app.hermes-rc.hermes-mobile .vault-sidebar.hermes-sidebar-open {
+    transform: translateX(0) !important;
+}
+.vault-app.hermes-rc.hermes-mobile .vault-graph {
+    display: none !important;
+}
+.vault-app.hermes-rc.hermes-mobile .vault-content {
+    grid-column: 1 !important;
+    padding: 16px 20px !important;
+    max-width: 100% !important;
+}
+.hermes-mobile-toggle {
+    display: none;
+    background: var(--bg-secondary);
+    border: 1px solid var(--border);
+    color: var(--text-secondary);
+    padding: 6px 12px;
+    border-radius: 4px;
+    cursor: pointer;
+    font-size: 14px;
+    margin-right: 8px;
+}
+.vault-app.hermes-rc.hermes-mobile .hermes-mobile-toggle { display: inline-block !important; }
+
+/* === Tablet (768px-1023px) === */
+.vault-app.hermes-rc.hermes-tablet {
+    grid-template-columns: 200px 1fr !important;
+    grid-template-rows: 48px 1fr 220px !important;
+    height: 100vh !important;
+}
+.vault-app.hermes-rc.hermes-tablet .vault-sidebar {
+    width: 200px !important;
+    max-width: 200px !important;
+}
+.vault-app.hermes-rc.hermes-tablet .vault-graph {
+    grid-column: 1 / -1 !important;
+    grid-row: 3 !important;
+    height: 220px !important;
+    border-left: none !important;
+    border-top: 1px solid var(--border) !important;
+}
+.vault-app.hermes-rc.hermes-tablet .vault-content {
+    grid-column: 2 !important;
+    grid-row: 2 !important;
+    padding: 20px 28px !important;
+}
+
+/* === Desktop (≥1024px): leave obv's default layout alone === */
+.vault-app.hermes-rc.hermes-desktop {
+    /* inherit obv's grid */
+}
+        `;
+        head.appendChild(style);
+        console.log('[HermesCustom] CSS injected');
+    };
+
+    // ============================================================
+    // 2. Layout application — called on init and on resize
+    // ============================================================
+
+    HermesCustom.applyLayout = function() {
+        const app = document.querySelector('.vault-app');
+        if (!app) {
+            // obv not loaded yet, retry
+            setTimeout(HermesCustom.applyLayout, 100);
+            return;
+        }
+
+        // Add our marker class (specificity booster)
+        if (!app.classList.contains('hermes-rc')) {
+            app.classList.add('hermes-rc');
+        }
+
+        const width = window.innerWidth;
+        // Remove all mode classes
+        app.classList.remove('hermes-mobile', 'hermes-tablet', 'hermes-desktop');
+        // Sidebar state reset
+        const sidebar = document.querySelector('.vault-sidebar');
+        if (sidebar) sidebar.classList.remove('hermes-sidebar-open');
+
+        if (width < BREAKPOINTS.mobile) {
+            app.classList.add('hermes-mobile');
+        } else if (width < BREAKPOINTS.tablet) {
+            app.classList.add('hermes-tablet');
+        } else {
+            app.classList.add('hermes-desktop');
+        }
+
+        // Add hamburger toggle in mobile mode
+        if (width < BREAKPOINTS.mobile) {
+            HermesCustom.ensureHamburgerButton();
+        }
+    };
+
+    HermesCustom.ensureHamburgerButton = function() {
+        if (document.querySelector('.hermes-mobile-toggle')) return;
+        const header = document.querySelector('.vault-header');
+        if (!header) return;
+        const btn = document.createElement('button');
+        btn.className = 'hermes-mobile-toggle';
+        btn.textContent = '☰';
+        btn.setAttribute('aria-label', 'Toggle file tree');
+        btn.onclick = (e) => {
+            e.stopPropagation();
+            const sidebar = document.querySelector('.vault-sidebar');
+            if (sidebar) sidebar.classList.toggle('hermes-sidebar-open');
+        };
+        header.insertBefore(btn, header.firstChild);
+    };
+
+    // Throttled resize handler
+    HermesCustom.setupResizeHandler = function() {
+        let resizeTimer;
+        let lastWidth = window.innerWidth;
+        window.addEventListener('resize', () => {
+            clearTimeout(resizeTimer);
+            resizeTimer = setTimeout(() => {
+                if (window.innerWidth !== lastWidth) {
+                    lastWidth = window.innerWidth;
+                    HermesCustom.applyLayout();
+                }
+            }, 150);
+        });
+    };
+
+    // ============================================================
+    // 3. Current-page highlighting
+    // ============================================================
+
     HermesCustom.getCurrentFile = function() {
-        // Method 1: ?file= query param (preferred)
         const params = new URLSearchParams(window.location.search);
         const fileParam = params.get('file');
         if (fileParam) return fileParam;
-
-        // Method 2: Parse from URL hash if obv uses hash-based routing
         if (window.location.hash) {
             const hashMatch = window.location.hash.match(/file=([^&]+)/);
             if (hashMatch) return decodeURIComponent(hashMatch[1]);
         }
-
-        // Method 3: Track via the last loadFile() call (set up in init)
         return HermesCustom._lastLoadedFile || null;
     };
 
-    /**
-     * Find all WikiLink targets in the currently loaded file's content.
-     * We hook into the renderMarkdown flow by tracking what was last loaded.
-     */
     HermesCustom.getConnectedFiles = function(currentFile) {
         if (!currentFile) return [];
-        // Use the global graph data loaded by obv's fetch('/api/vault/graph')
         const graphData = HermesCustom._graphData;
         if (!graphData) return [];
-
         const connections = graphData.edges
             .filter(e => e.source === currentFile)
             .map(e => e.target);
-
-        // Also outgoing from current file (WikiLinks from current page)
-        // And bidirectional awareness
         return connections;
     };
 
-    /**
-     * Highlight the current node + connected nodes in the 3D Graph.
-     * Uses obv's global graph variables (graphScene, graphNodeObjects).
-     */
     HermesCustom.highlightCurrentNode = function() {
         const currentFile = HermesCustom.getCurrentFile();
         if (!currentFile) return;
-
-        // Hook into obv's globals (set after graph render)
-        if (typeof window.graphScene === 'undefined' || !window.graphNodeObjects) {
-            // Graph not yet built — try again shortly
+        if (typeof window.graphNodeObjects === 'undefined' || !window.graphNodeObjects) {
             setTimeout(HermesCustom.highlightCurrentNode, 500);
             return;
         }
@@ -79,26 +264,22 @@
         const connected = new Set(HermesCustom.getConnectedFiles(currentFile));
         connected.add(currentFile);
 
-        // Iterate node meshes and adjust material
         window.graphNodeObjects.forEach((mesh, nodeId) => {
             const isCurrent = (nodeId === currentFile);
             const isConnected = connected.has(nodeId) && !isCurrent;
 
             if (isCurrent) {
-                // Bright + slightly larger + emissive glow
-                mesh.material.color.setHex(0xFFD700); // gold
+                mesh.material.color.setHex(0xFFD700);
                 mesh.material.emissive.setHex(0xFFD700);
                 mesh.material.emissiveIntensity = 0.6;
                 mesh.scale.set(1.5, 1.5, 1.5);
             } else if (isConnected) {
-                // Brighter than default, smaller than current
-                mesh.material.color.setHex(0x89b4fa); // light blue
+                mesh.material.color.setHex(0x89b4fa);
                 mesh.material.emissive.setHex(0x89b4fa);
                 mesh.material.emissiveIntensity = 0.3;
                 mesh.scale.set(1.1, 1.1, 1.1);
             } else {
-                // Dim everything else
-                mesh.material.color.setHex(0x313244); // muted
+                mesh.material.color.setHex(0x313244);
                 mesh.material.emissiveIntensity = 0;
                 mesh.material.opacity = 0.2;
                 mesh.material.transparent = true;
@@ -107,7 +288,7 @@
     };
 
     // ============================================================
-    // 2. Click-to-navigate on 3D Graph
+    // 4. Click-to-navigate on 3D Graph
     // ============================================================
 
     HermesCustom.setupGraphClickHandler = function() {
@@ -137,146 +318,46 @@
                 }
             }
         });
+        console.log('[HermesCustom] Graph click handler attached');
     };
 
     // ============================================================
-    // 3. Responsive layout
+    // 5. URL-based navigation
     // ============================================================
 
-    HermesCustom.responsiveLayout = function() {
-        const applyLayout = () => {
-            const app = document.querySelector('.vault-app');
-            if (!app) return;
+    HermesCustom.updateURL = function(path) {
+        const newURL = `?file=${encodeURIComponent(path)}`;
+        window.history.pushState({}, '', newURL);
+    };
 
-            const width = window.innerWidth;
-            if (width < 768) {
-                // Mobile: tree collapses to hamburger, graph hidden by default
-                app.classList.add('mobile-mode');
-                app.classList.remove('graph-visible');
-            } else if (width < 1024) {
-                // Tablet: tree visible, graph collapses to bottom panel
-                app.classList.add('tablet-mode');
-                app.classList.remove('mobile-mode');
-            } else {
-                // Desktop: full 3-panel layout
-                app.classList.remove('mobile-mode', 'tablet-mode');
-            }
+    // ============================================================
+    // 6. loadFile hook — track current file
+    // ============================================================
+
+    HermesCustom.hookLoadFile = function() {
+        if (typeof window.loadFile !== 'function') {
+            setTimeout(HermesCustom.hookLoadFile, 200);
+            return;
+        }
+        if (window.loadFile._hermesPatched) return;
+
+        const originalLoadFile = window.loadFile;
+        window.loadFile = function(path) {
+            HermesCustom._lastLoadedFile = path;
+            HermesCustom.updateURL(path);
+            const result = originalLoadFile.apply(this, arguments);
+            setTimeout(HermesCustom.highlightCurrentNode, 300);
+            return result;
         };
-
-        // Throttled resize handler
-        let resizeTimer;
-        window.addEventListener('resize', () => {
-            clearTimeout(resizeTimer);
-            resizeTimer = setTimeout(applyLayout, 150);
-        });
-
-        applyLayout(); // Initial
-    };
-
-    /**
-     * Inject responsive CSS into <head> (since vault.html doesn't have these)
-     * Must run early so it doesn't conflict with obv's layout.
-     */
-    HermesCustom.injectResponsiveCSS = function() {
-        if (document.getElementById('hermes-custom-css')) return;
-
-        const style = document.createElement('style');
-        style.id = 'hermes-custom-css';
-        style.textContent = `
-/* === Tablet (768px - 1023px): graph → bottom panel === */
-@media (max-width: 1023px) {
-    .vault-app.tablet-mode {
-        grid-template-columns: 240px 1fr !important;
-        grid-template-rows: 48px 1fr 200px !important;
-    }
-    .vault-app.tablet-mode .vault-graph {
-        grid-column: 1 / -1 !important;
-        grid-row: 3 !important;
-        border-left: none !important;
-        border-top: 1px solid var(--border);
-    }
-    .vault-app.tablet-mode .vault-content {
-        grid-column: 2 !important;
-    }
-}
-
-/* === Mobile (<768px): tree → hamburger menu === */
-@media (max-width: 767px) {
-    .vault-app.mobile-mode {
-        grid-template-columns: 1fr !important;
-        grid-template-rows: 48px 1fr !important;
-    }
-    .vault-app.mobile-mode .vault-sidebar {
-        position: fixed;
-        top: 48px;
-        left: 0;
-        bottom: 0;
-        width: 280px;
-        transform: translateX(-100%);
-        transition: transform 0.2s ease;
-        z-index: 100;
-    }
-    .vault-app.mobile-mode .vault-sidebar.open {
-        transform: translateX(0);
-    }
-    .vault-app.mobile-mode .vault-graph {
-        display: none;
-    }
-}
-
-/* === Hamburger toggle button (mobile only) === */
-.hermes-mobile-toggle {
-    display: none;
-    background: var(--bg-secondary);
-    border: 1px solid var(--border);
-    color: var(--text-secondary);
-    padding: 4px 10px;
-    border-radius: 4px;
-    cursor: pointer;
-    font-size: 12px;
-}
-@media (max-width: 767px) {
-    .hermes-mobile-toggle { display: inline-block; }
-}
-        `;
-        document.head.appendChild(style);
-
-        // Add hamburger button to header
-        const header = document.querySelector('.vault-header');
-        if (header && !document.querySelector('.hermes-mobile-toggle')) {
-            const btn = document.createElement('button');
-            btn.className = 'hermes-mobile-toggle';
-            btn.textContent = '☰ Tree';
-            btn.onclick = () => {
-                const sidebar = document.querySelector('.vault-sidebar');
-                if (sidebar) sidebar.classList.toggle('open');
-            };
-            header.insertBefore(btn, header.firstChild);
-        }
+        window.loadFile._hermesPatched = true;
+        console.log('[HermesCustom] loadFile() hooked');
     };
 
     // ============================================================
-    // Init: wire everything together
+    // 7. Graph data fetch (for highlight logic)
     // ============================================================
 
-    HermesCustom.init = function() {
-        console.log('[HermesCustom] init');
-        HermesCustom.injectResponsiveCSS();
-        HermesCustom.responsiveLayout();
-
-        // Hook into obv's loadFile to track current file + re-highlight
-        if (typeof window.loadFile === 'function') {
-            const originalLoadFile = window.loadFile;
-            window.loadFile = function(path) {
-                HermesCustom._lastLoadedFile = path;
-                const result = originalLoadFile.apply(this, arguments);
-                // Re-highlight after content renders
-                setTimeout(HermesCustom.highlightCurrentNode, 300);
-                return result;
-            };
-        }
-
-        // Fetch graph data once for highlight logic
+    HermesCustom.loadGraphData = function() {
         fetch('/api/vault/graph')
             .then(r => r.json())
             .then(data => {
@@ -285,18 +366,33 @@
                 HermesCustom.highlightCurrentNode();
             })
             .catch(err => console.warn('[HermesCustom] Graph fetch failed:', err));
+    };
 
-        // Click handler + responsive layout (need to wait for Three.js to init)
+    // ============================================================
+    // Init
+    // ============================================================
+
+    HermesCustom.init = function() {
+        console.log('[HermesCustom] init v2 (responsive-fix)');
+        HermesCustom.injectResponsiveCSS();
+        HermesCustom.hookLoadFile();
+        HermesCustom.applyLayout();
+        HermesCustom.setupResizeHandler();
+        HermesCustom.loadGraphData();
+
+        // Graph click handler needs Three.js to be ready
         setTimeout(() => {
             HermesCustom.setupGraphClickHandler();
         }, 1500);
     };
 
-    // Auto-init when DOM is ready
+    // Auto-init
     if (document.readyState === 'loading') {
         document.addEventListener('DOMContentLoaded', HermesCustom.init);
     } else {
-        HermesCustom.init();
+        // DOM already ready — but obv's main script may not have run yet.
+        // Defer slightly to let obv set up the layout first.
+        setTimeout(HermesCustom.init, 50);
     }
 
 })();
diff --git a/vault.html b/vault.html
index bd11fb2..091c626 100644
--- a/vault.html
+++ b/vault.html
@@ -349,6 +349,6 @@ async function loadGraph() {
 loadTree();
 loadGraph();
 </script>
-</body>
 <script src="vault-custom.js"></script>
+</body>
 </html>
