diff --git a/public/css/arf.css b/public/css/arf.css
index 3e4e894..2c52415 100644
--- a/public/css/arf.css
+++ b/public/css/arf.css
@@ -70,6 +70,8 @@ body {
   color: var(--color-text-primary);
   font-size: var(--font-size-base);
   font-family: var(--font-family);
+  margin: 0;
+  overflow: hidden;
 }
 
 noscript p {
@@ -94,7 +96,8 @@ noscript p {
 svg {
   display: block;
   width: 100%;
-  height: auto;
+  /* Fill remaining viewport height below header + search bar */
+  height: calc(100vh - 120px);
   cursor: grab;
 }
 
@@ -109,7 +112,6 @@ svg:active {
   position: relative;
   font-size: var(--font-size-xl);
   font-weight: bold;
-  top: 20px;
   text-align: center;
   color: var(--color-header);
   padding: var(--space-2) var(--space-4);
@@ -393,10 +395,6 @@ a {
     padding: var(--space-2) var(--space-3);
   }
 
-  #header hr {
-    display: none;
-  }
-
   #header-actions {
     right: var(--space-3);
   }
@@ -417,7 +415,7 @@ a {
 
   /* Maximize SVG tree viewport */
   svg {
-    min-height: 60vh;
+    height: calc(100vh - 80px);
   }
 
   /* Floating notes button (mobile only) */
diff --git a/public/index.html b/public/index.html
index 4abff3c..9fc8790 100644
--- a/public/index.html
+++ b/public/index.html
@@ -31,7 +31,6 @@
           <button id="header-notes-btn" onclick="toggleNotesPanel()">Notes</button>
           <button id="header-theme-toggle" onclick="goDark()">Light Mode</button>
         </div>
-          <hr/>
       </div>
       <div id="search-container">
         <input type="text" id="search-input" placeholder="Search tools..." autocomplete="off" aria-label="Search OSINT tools">
diff --git a/public/js/arf.js b/public/js/arf.js
index 7bbe86a..5919e9e 100644
--- a/public/js/arf.js
+++ b/public/js/arf.js
@@ -84,38 +84,36 @@ d3.json("arf.json").then(function(json) {
 
   root.children.forEach(collapse);
 
-  // On mobile, stretch the viewBox to match the actual rendered aspect ratio
-  // so the zoom-to-fill calculation uses the real visible area, not the
-  // fixed 1280x800 letterboxed region.
-  if (window.innerWidth <= 768) {
-    var rect = svgEl.node().getBoundingClientRect();
-    if (rect.width && rect.height) {
-      svgH = Math.round(svgW * (rect.height / rect.width));
-      svgEl.attr("viewBox", "0 0 " + svgW + " " + svgH);
-    }
-
-    // Run tree layout to get final node positions, then compute zoom from data.
-    tree(root);
-    root.descendants().forEach(function(d) { d.y = d.depth * 180; });
-    var visibleNodes = root.descendants();
-    var minX = Infinity, maxX = -Infinity, minY = Infinity, maxY = -Infinity;
-    visibleNodes.forEach(function(d) {
-      if (d.x < minX) minX = d.x;
-      if (d.x > maxX) maxX = d.x;
-      if (d.y < minY) minY = d.y;
-      if (d.y > maxY) maxY = d.y;
-    });
-    var pad = 40;
-    var bw = (maxY - minY) || 1;
-    var bh = (maxX - minX) || 1;
-    var k = Math.min((svgW - pad * 2) / bw, (svgH - pad * 2) / bh, 3);
-    var cx = (minY + maxY) / 2;
-    var cy = (minX + maxX) / 2;
-    var tx = svgW / 2 - margin[3] - cx * k;
-    var ty = svgH / 2 - margin[0] - cy * k;
-    svgEl.call(zoom.transform, d3.zoomIdentity.translate(tx, ty).scale(k));
+  // Stretch the viewBox to match the actual rendered aspect ratio so the
+  // zoom-to-fill calculation uses the real visible area, not the fixed
+  // 1280x800 letterboxed region.
+  var rect = svgEl.node().getBoundingClientRect();
+  if (rect.width && rect.height) {
+    svgH = Math.round(svgW * (rect.height / rect.width));
+    svgEl.attr("viewBox", "0 0 " + svgW + " " + svgH);
   }
 
+  // Run tree layout to get final node positions, then compute zoom from data.
+  tree(root);
+  root.descendants().forEach(function(d) { d.y = d.depth * 180; });
+  var visibleNodes = root.descendants();
+  var minX = Infinity, maxX = -Infinity, minY = Infinity, maxY = -Infinity;
+  visibleNodes.forEach(function(d) {
+    if (d.x < minX) minX = d.x;
+    if (d.x > maxX) maxX = d.x;
+    if (d.y < minY) minY = d.y;
+    if (d.y > maxY) maxY = d.y;
+  });
+  var pad = 40;
+  var bw = (maxY - minY) || 1;
+  var bh = (maxX - minX) || 1;
+  var k = Math.min((svgW - pad * 2) / bw, (svgH - pad * 2) / bh, 3);
+  var cx = (minY + maxY) / 2;
+  var cy = (minX + maxX) / 2;
+  var tx = svgW / 2 - margin[3] - cx * k;
+  var ty = svgH / 2 - margin[0] - cy * k;
+  svgEl.call(zoom.transform, d3.zoomIdentity.translate(tx, ty).scale(k));
+
   update(root);
   initSearch();
 });