diff --git a/frontend/index.html b/frontend/index.html
index b49d604..9dce13f 100644
--- a/frontend/index.html
+++ b/frontend/index.html
@@ -11,8 +11,30 @@
             box-sizing: border-box;
         }
 
+        :root {
+            --bg: #f0f0f4;
+            --tab-bg: #ffffff;
+            --tab-hover: #e8e8ed;
+            --tab-border: #cfcfd8;
+            --text: #15141a;
+            --text-muted: #5b5b66;
+            --viewer-bg: #f0f0f4;
+        }
+
+        @media (prefers-color-scheme: dark) {
+            :root {
+                --bg: #1c1b22;
+                --tab-bg: #2b2a33;
+                --tab-hover: #42414d;
+                --tab-border: #3a3944;
+                --text: #fbfbfe;
+                --text-muted: #8f8f9d;
+                --viewer-bg: #1c1b22;
+            }
+        }
+
         body {
-            background: #1c1b22;
+            background: var(--bg);
             overflow-x: hidden;
             font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
         }
@@ -29,21 +51,72 @@
             align-items: center;
             gap: 6px;
             padding: 6px 12px;
-            margin: 0 1px;
-            background: #2b2a33;
-            border-radius: 8px 8px 0 0;
             cursor: pointer;
             flex-shrink: 0;
             max-width: 200px;
             min-width: 100px;
             height: 36px;
-            border: 1px solid #3a3944;
-            border-bottom: none;
             transition: background 0.15s;
+            /* Default: Firefox inactive tab style */
+            border-radius: 4px;
+            border: none;
+            margin: 0 1px;
+            background: transparent;
         }
 
         .tab:hover {
-            background: #42414d;
+            background: var(--tab-hover);
+            border-radius: 4px;
+        }
+
+        /* Firefox selected tab — solid bg, rounded top, connects to content below */
+        .browser-firefox .tab-active,
+        .browser-firefox .tab-active:hover {
+            background: var(--tab-bg);
+            border-radius: 8px 8px 0 0;
+            box-shadow: 0 1px 0 0 var(--tab-bg);
+        }
+
+        /* Chrome / Chromium — inactive tabs: no bg, thin separators between */
+        .browser-chrome .tab {
+            border-radius: 0;
+            margin: 0;
+            padding: 6px 14px;
+            border-right: 1px solid var(--tab-border);
+        }
+
+        .browser-chrome .tab:hover {
+            background: var(--tab-hover);
+            border-radius: 8px 8px 0 0;
+            border-right: 1px solid transparent;
+        }
+
+        /* Chrome selected tab — raised, rounded top, solid bg */
+        .browser-chrome .tab-active,
+        .browser-chrome .tab-active:hover {
+            background: var(--tab-bg);
+            border-radius: 10px 10px 0 0;
+            border-right: 1px solid transparent;
+            box-shadow: 0 -1px 4px rgba(0, 0, 0, 0.1);
+        }
+
+        /* Safari — flat pill, very minimal */
+        .browser-safari .tab {
+            border-radius: 6px;
+            margin: 0 2px;
+            height: 32px;
+            padding: 4px 10px;
+        }
+
+        .browser-safari .tab:hover {
+            background: var(--tab-hover);
+        }
+
+        /* Safari selected tab — solid pill, slightly elevated */
+        .browser-safari .tab-active,
+        .browser-safari .tab-active:hover {
+            background: var(--tab-bg);
+            box-shadow: 0 1px 3px rgba(0, 0, 0, 0.12);
         }
 
         .tab-icon {
@@ -55,7 +128,7 @@
 
         .tab-title {
             font-size: 12px;
-            color: #fbfbfe;
+            color: var(--text);
             overflow: hidden;
             text-overflow: ellipsis;
             white-space: nowrap;
@@ -68,7 +141,7 @@
         .tab-external::after {
             content: "↗";
             font-size: 9px;
-            color: #8f8f9d;
+            color: var(--text-muted);
             position: absolute;
             top: 3px;
             right: 4px;
@@ -97,9 +170,9 @@
         .iframe-viewer {
             width: 100%;
             height: 75vh;
-            background: #1c1b22;
-            border-top: 2px solid #3a3944;
-            border-bottom: 2px solid #3a3944;
+            background: var(--viewer-bg);
+            border-top: 2px solid var(--tab-border);
+            border-bottom: 2px solid var(--tab-border);
         }
 
         .iframe-header {
@@ -107,7 +180,7 @@
             align-items: center;
             gap: 8px;
             padding: 6px 12px;
-            background: #2b2a33;
+            background: var(--tab-bg);
         }
 
         .iframe-header .tab-title {
@@ -116,19 +189,19 @@
         }
 
         .iframe-header a {
-            color: #8f8f9d;
+            color: var(--text-muted);
             font-size: 12px;
             text-decoration: none;
         }
 
         .iframe-header a:hover {
-            color: #fbfbfe;
+            color: var(--text);
         }
 
         .iframe-close {
             background: none;
             border: none;
-            color: #fbfbfe;
+            color: var(--text);
             font-size: 16px;
             cursor: pointer;
             padding: 2px 6px;
@@ -136,7 +209,7 @@
         }
 
         .iframe-close:hover {
-            background: #42414d;
+            background: var(--tab-hover);
         }
 
         .iframe-viewer iframe {
@@ -147,7 +220,7 @@
         }
 
         #loading {
-            color: #8f8f9d;
+            color: var(--text-muted);
             text-align: center;
             padding: 20px;
             font-size: 14px;
diff --git a/frontend/site.js b/frontend/site.js
index f21ad53..04909cd 100644
--- a/frontend/site.js
+++ b/frontend/site.js
@@ -14,6 +14,15 @@ const loadedBundles = new Set();
 const container = document.getElementById("tab-container");
 const loadingEl = document.getElementById("loading");
 
+// Detect browser and set class on body for tab styling
+function detectBrowser() {
+    const ua = navigator.userAgent;
+    if (ua.includes("Firefox")) return "firefox";
+    if (ua.includes("Safari") && !ua.includes("Chrome")) return "safari";
+    return "chrome"; // Chrome, Edge, Opera, Brave, etc.
+}
+document.body.classList.add(`browser-${detectBrowser()}`);
+
 // How many tabs fit in one row?
 function tabsPerRow() {
     const tabWidth = 160; // avg tab width in px (min 100, max 200)
@@ -88,7 +97,7 @@ function createRow(entries, rowIndex) {
     const row = document.createElement("div");
     row.className = "tab-row";
 
-    const speed = 60 + (rng() * 40); // 60-100s per cycle
+    const speed = 90 + (rng() * 60); // 90-150s per cycle
     row.style.setProperty("--speed", `${speed}s`);
 
     // Random direction
@@ -160,11 +169,16 @@ window.addEventListener("scroll", async () => {
 
 // Inline iframe viewer
 let activeViewer = null;
+let activeTab = null;
 
 function openInlineViewer(tabEl, entry, url) {
     // Close existing viewer
     closeInlineViewer();
 
+    // Mark tab as active
+    tabEl.classList.add("tab-active");
+    activeTab = tabEl;
+
     // Find the row this tab belongs to
     const row = tabEl.closest(".tab-row");
 
@@ -220,6 +234,10 @@ function closeInlineViewer() {
         activeViewer.remove();
         activeViewer = null;
     }
+    if (activeTab) {
+        activeTab.classList.remove("tab-active");
+        activeTab = null;
+    }
 }
 
 document.addEventListener("keydown", (e) => {