diff --git a/static/css/style.css b/static/css/style.css
index ce200fb..5b39747 100644
--- a/static/css/style.css
+++ b/static/css/style.css
@@ -58,6 +58,8 @@ html {
     font-size: 16px;
     -webkit-font-smoothing: antialiased;
     -moz-osx-font-smoothing: grayscale;
+    background-color: var(--yt-bg-primary);
+    /* Fix white bar issue */
 }
 
 body {
@@ -66,6 +68,7 @@ body {
     color: var(--yt-text-primary);
     line-height: 1.4;
     overflow-x: hidden;
+    min-height: 100vh;
 }
 
 a {
@@ -194,7 +197,7 @@ button {
 .yt-search-input {
     flex: 1;
     height: 40px;
-    background: var(--yt-bg-primary);
+    background: var(--yt-bg-secondary);
     border: 1px solid var(--yt-border);
     border-right: none;
     border-radius: 20px 0 0 20px;
@@ -371,6 +374,7 @@ button {
     padding: 12px 0 24px;
     overflow-x: auto;
     scrollbar-width: none;
+    flex-wrap: nowrap;
     -ms-overflow-style: none;
 }
 
@@ -430,7 +434,12 @@ button {
     width: 100%;
     height: 100%;
     object-fit: cover;
-    transition: transform 0.3s ease;
+    opacity: 0;
+    transition: opacity 0.5s ease, transform 0.3s ease;
+}
+
+.yt-thumbnail.loaded {
+    opacity: 1;
 }
 
 .yt-video-card:hover .yt-thumbnail {
@@ -819,11 +828,28 @@ button {
 
 @media (max-width: 768px) {
     .yt-header-center {
-        display: none;
+        display: flex;
+        /* Show search on mobile */
+        margin: 0 8px;
+        max-width: none;
+        flex: 1;
+        justify-content: center;
+    }
+
+    .yt-search-input {
+        padding: 0 12px;
+        font-size: 14px;
+        border-radius: 18px 0 0 18px;
+    }
+
+    .yt-search-btn {
+        width: 48px;
+        border-radius: 0 18px 18px 0;
     }
 
     .yt-mobile-search {
-        display: flex;
+        display: none;
+        /* Hide icon since bar is visible */
     }
 
     .yt-signin-text {
@@ -831,8 +857,9 @@ button {
     }
 
     .yt-video-grid {
-        grid-template-columns: 1fr;
-        gap: 0;
+        grid-template-columns: repeat(2, 1fr);
+        gap: 8px;
+        padding: 0 4px;
     }
 
     .yt-video-card {
@@ -851,6 +878,10 @@ button {
     .yt-categories {
         padding: 8px 0 16px;
         gap: 8px;
+        display: flex;
+        flex-wrap: nowrap;
+        overflow-x: auto;
+        white-space: nowrap;
     }
 
     .yt-category-pill {
@@ -1170,4 +1201,131 @@ button {
     white-space: nowrap;
     overflow: hidden;
     text-overflow: ellipsis;
+}
+
+/* Floating Back Button */
+.yt-floating-back {
+    position: fixed;
+    bottom: 24px;
+    right: 24px;
+    width: 56px;
+    height: 56px;
+    background: var(--yt-accent-blue);
+    color: white;
+    border-radius: 50%;
+    display: none;
+    /* Hidden on desktop */
+    align-items: center;
+    justify-content: center;
+    font-size: 20px;
+    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
+    z-index: 2000;
+    cursor: pointer;
+    transition: transform 0.2s, background 0.2s;
+    border: none;
+}
+
+.yt-floating-back:active {
+    transform: scale(0.95);
+    background: #2c95dd;
+}
+
+@media (max-width: 768px) {
+    .yt-floating-back {
+        display: flex;
+        /* Show only on mobile */
+    }
+}
+
+/* Mobile V2 Overrides */
+@media (max-width: 768px) {
+    .yt-video-grid {
+        grid-template-columns: repeat(2, 1fr) !important;
+        gap: 8px !important;
+        padding: 0 4px !important;
+    }
+
+    .yt-video-card {
+        padding: 4px !important;
+    }
+
+    .yt-categories {
+        display: flex !important;
+        flex-wrap: nowrap !important;
+        grid-template-rows: none !important;
+        padding-right: 16px !important;
+        white-space: nowrap !important;
+    }
+
+    .yt-floating-back {
+        background: var(--yt-accent-red) !important;
+    }
+
+    .yt-floating-back:active {
+        background: #cc0000 !important;
+    }
+}
+
+/* Mobile V4 Overrides - Pixel Perfect Polish */
+@media (max-width: 768px) {
+
+    /* Optimize Categories */
+    .yt-categories {
+        padding: 8px 0 8px 8px !important;
+        /* Left padding for start, no right padding */
+        width: 100% !important;
+        mask-image: linear-gradient(to right, black 95%, transparent 100%);
+        -webkit-mask-image: linear-gradient(to right, black 95%, transparent 100%);
+    }
+
+    .yt-chip {
+        font-size: 12px !important;
+        padding: 6px 12px !important;
+        height: 30px !important;
+        border-radius: 6px !important;
+    }
+
+    /* Maximize Thumbnails */
+    .yt-main {
+        padding: 0 !important;
+        /* Edge to edge */
+    }
+
+    .yt-video-grid {
+        gap: 1px !important;
+        /* Minimal gap */
+        padding: 0 !important;
+        background: var(--yt-bg-primary);
+    }
+
+    .yt-video-card,
+    .skeleton-card {
+        padding: 0 !important;
+        margin-bottom: 4px !important;
+    }
+
+    .yt-thumbnail-container,
+    .skeleton-thumb {
+        border-radius: 6px !important;
+    }
+
+    .yt-video-details {
+        padding: 6px 8px 12px !important;
+    }
+
+    .yt-video-title {
+        font-size: 13px !important;
+        line-height: 1.2 !important;
+    }
+
+    /* Reduce header padding to match */
+    .yt-header {
+        padding: 0 12px !important;
+    }
+
+    /* Filter bar spacing */
+    .yt-filter-bar {
+        padding-left: 0 !important;
+        padding-right: 0 !important;
+    }
 }
\ No newline at end of file
diff --git a/static/js/main.js b/static/js/main.js
index c471786..218e402 100644
--- a/static/js/main.js
+++ b/static/js/main.js
@@ -36,6 +36,31 @@ let currentPage = 1;
 let isLoading = false;
 let hasMore = true; // Track if there are more videos to load
 
+// --- Lazy Loading ---
+const imageObserver = new IntersectionObserver((entries, observer) => {
+    entries.forEach(entry => {
+        if (entry.isIntersecting) {
+            const img = entry.target;
+            const src = img.getAttribute('data-src');
+            if (src) {
+                img.src = src;
+                img.onload = () => img.classList.add('loaded');
+                img.removeAttribute('data-src');
+            }
+            observer.unobserve(img);
+        }
+    });
+}, {
+    rootMargin: '50px 0px',
+    threshold: 0.1
+});
+
+window.observeImages = function () {
+    document.querySelectorAll('img[data-src]').forEach(img => {
+        imageObserver.observe(img);
+    });
+};
+
 // --- Infinite Scroll ---
 function initInfiniteScroll() {
     const observer = new IntersectionObserver((entries) => {
@@ -234,7 +259,7 @@ async function loadTrending(reset = true) {
 
                     card.innerHTML = `
                         <div class="yt-thumbnail-container">
-                            <img class="yt-thumbnail" src="${video.thumbnail}" alt="${escapeHtml(video.title)}" loading="lazy">
+                            <img class="yt-thumbnail" data-src="${video.thumbnail}" alt="${escapeHtml(video.title)}">
                             ${video.duration ? `<span class="yt-duration">${video.duration}</span>` : ''}
                         </div>
                         <div class="yt-video-details">
@@ -255,6 +280,7 @@ async function loadTrending(reset = true) {
                 sectionDiv.appendChild(scrollContainer);
                 resultsArea.appendChild(sectionDiv);
             });
+            if (window.observeImages) window.observeImages();
             return;
         }
 
@@ -299,7 +325,7 @@ function displayResults(videos, append = false) {
             card.style.width = '100%';
             card.style.maxWidth = '200px';
             card.innerHTML = `
-                <img src="${video.thumbnail}" class="yt-short-thumb" style="width:100%; aspect-ratio:9/16; height:auto;" loading="lazy">
+                <img data-src="${video.thumbnail}" class="yt-short-thumb" style="width:100%; aspect-ratio:9/16; height:auto;">
                 <p class="yt-short-title">${escapeHtml(video.title)}</p>
                 <p class="yt-short-views">${formatViews(video.view_count)} views</p>
              `;
@@ -308,7 +334,7 @@ function displayResults(videos, append = false) {
             card.className = 'yt-video-card';
             card.innerHTML = `
                 <div class="yt-thumbnail-container">
-                    <img class="yt-thumbnail" src="${video.thumbnail}" alt="${escapeHtml(video.title)}" loading="lazy">
+                    <img class="yt-thumbnail" data-src="${video.thumbnail}" alt="${escapeHtml(video.title)}">
                     ${video.duration ? `<span class="yt-duration">${video.duration}</span>` : ''}
                 </div>
                 <div class="yt-video-details">
@@ -337,6 +363,8 @@ function displayResults(videos, append = false) {
         });
         resultsArea.appendChild(card);
     });
+
+    if (window.observeImages) window.observeImages();
 }
 
 // Format view count (YouTube style)
@@ -425,28 +453,51 @@ function initTheme() {
     let savedTheme = localStorage.getItem('theme');
 
     // If no saved preference, use Time of Day (Auto)
-    // Approximation: 6 AM to 6 PM is Light (Sunrise/Sunset)
     if (!savedTheme) {
         const hour = new Date().getHours();
         savedTheme = (hour >= 6 && hour < 18) ? 'light' : 'dark';
     }
 
-    document.documentElement.setAttribute('data-theme', savedTheme);
+    setTheme(savedTheme, false); // Initial set without saving (already saved or computed)
+}
 
-    // Update toggle if exists
-    const toggle = document.getElementById('themeToggle');
-    if (toggle) {
-        toggle.checked = savedTheme === 'dark';
+function setTheme(theme, save = true) {
+    document.documentElement.setAttribute('data-theme', theme);
+    if (save) {
+        localStorage.setItem('theme', theme);
+    }
+
+    // Update UI Buttons (if on settings page)
+    const btnLight = document.getElementById('themeBtnLight');
+    const btnDark = document.getElementById('themeBtnDark');
+
+    if (btnLight && btnDark) {
+        btnLight.classList.remove('active');
+        btnDark.classList.remove('active');
+
+        if (theme === 'light') btnLight.classList.add('active');
+        else btnDark.classList.add('active');
     }
 }
 
-function toggleTheme() {
-    const current = document.documentElement.getAttribute('data-theme');
-    const newTheme = current === 'light' ? 'dark' : 'light';
+// Ensure theme persists on back navigation (BFCache)
+window.addEventListener('pageshow', (event) => {
+    // Re-apply theme from storage to ensure it matches user preference
+    // even if page was restored from cache with old state
+    const savedTheme = localStorage.getItem('theme');
+    if (savedTheme) {
+        setTheme(savedTheme, false);
+    } else {
+        initTheme();
+    }
+});
 
-    document.documentElement.setAttribute('data-theme', newTheme);
-    localStorage.setItem('theme', newTheme);
-}
+// Sync across tabs
+window.addEventListener('storage', (event) => {
+    if (event.key === 'theme') {
+        setTheme(event.newValue, false);
+    }
+});
 
 // --- Profile Logic ---
 async function updateProfile(e) {
diff --git a/templates/index.html b/templates/index.html
index 2fd71de..d5b9504 100644
--- a/templates/index.html
+++ b/templates/index.html
@@ -42,26 +42,11 @@
 
 
 <!-- Shorts Section -->
-<div id="shortsSection" class="yt-section">
-    <div class="yt-section-header">
-        <h2><i class="fas fa-bolt"></i> Shorts</h2>
-    </div>
-    <div class="yt-shorts-container">
-        <button class="yt-shorts-arrow yt-shorts-left" onclick="scrollShorts('left')">
-            <i class="fas fa-chevron-left"></i>
-        </button>
-        <div id="shortsGrid" class="yt-shorts-grid">
-            <!-- Shorts loaded via JS -->
-        </div>
-        <button class="yt-shorts-arrow yt-shorts-right" onclick="scrollShorts('right')">
-            <i class="fas fa-chevron-right"></i>
-        </button>
-    </div>
-</div>
+
 
 <!-- Videos Section -->
 <div id="videosSection" class="yt-section">
-    <div class="yt-section-header">
+    <div class="yt-section-header" style="display:none;">
         <h2><i class="fas fa-play-circle"></i> Videos</h2>
     </div>
     <div id="resultsArea" class="yt-video-grid">
@@ -356,39 +341,44 @@
         border-radius: 12px;
         object-fit: cover;
         background: var(--yt-bg-secondary);
+        opacity: 0;
+        transition: opacity 0.5s ease;
     }
 
-    .yt-short-title {
-        font-size: 14px;
-        font-weight: 500;
-        margin-top: 8px;
-        display: -webkit-box;
-        -webkit-line-clamp: 2;
-        line-clamp: 2;
-        -webkit-box-orient: vertical;
-        overflow: hidden;
-    }
+    .yt-short-thumb.loaded {
+        opacity: 1;
 
-    .yt-short-views {
-        font-size: 12px;
-        color: var(--yt-text-secondary);
-        margin-top: 4px;
-    }
-
-    @media (max-width: 768px) {
-        .yt-shorts-arrow {
-            display: none;
+        .yt-short-title {
+            font-size: 14px;
+            font-weight: 500;
+            margin-top: 8px;
+            display: -webkit-box;
+            -webkit-line-clamp: 2;
+            line-clamp: 2;
+            -webkit-box-orient: vertical;
+            overflow: hidden;
         }
 
-        .yt-filter-bar {
-            padding: 0 10px;
-            top: 56px;
+        .yt-short-views {
+            font-size: 12px;
+            color: var(--yt-text-secondary);
+            margin-top: 4px;
         }
 
-        .yt-sort-container {
-            /* Legacy override if needed */
+        @media (max-width: 768px) {
+            .yt-shorts-arrow {
+                display: none;
+            }
+
+            .yt-filter-bar {
+                padding: 0 10px;
+                top: 56px;
+            }
+
+            .yt-sort-container {
+                /* Legacy override if needed */
+            }
         }
-    }
 </style>
 
 <script>
@@ -461,13 +451,14 @@
                     const card = document.createElement('div');
                     card.className = 'yt-short-card';
                     card.innerHTML = `
-                    <img src="${video.thumbnail}" class="yt-short-thumb" loading="lazy">
+                    <img data-src="${video.thumbnail}" class="yt-short-thumb">
                     <p class="yt-short-title">${escapeHtml(video.title)}</p>
                     <p class="yt-short-views">${formatViews(video.view_count)} views</p>
                 `;
                     card.onclick = () => window.location.href = `/watch?v=${video.id}`;
                     shortsGrid.appendChild(card);
                 });
+                if (window.observeImages) window.observeImages();
             } else {
                 shortsGrid.innerHTML = '<p style="color:var(--yt-text-secondary);padding:20px;">No shorts found</p>';
             }
diff --git a/templates/layout.html b/templates/layout.html
index e983131..a96f761 100644
--- a/templates/layout.html
+++ b/templates/layout.html
@@ -45,10 +45,6 @@
                 <button class="yt-menu-btn" onclick="toggleSidebar()" aria-label="Menu">
                     <i class="fas fa-bars"></i>
                 </button>
-                <button class="yt-menu-btn" id="headerBackBtn" onclick="history.back()" aria-label="Back"
-                    style="display:none;">
-                    <i class="fas fa-arrow-left"></i>
-                </button>
                 <a href="/" class="yt-logo"
                     style="text-decoration: none; display: flex; align-items: center; gap: 4px;">
                     <span style="color: #ff0000; font-size: 24px;"><i class="fas fa-play-circle"></i></span>
@@ -67,9 +63,10 @@
             </div>
 
             <div class="yt-header-end">
-                <button class="yt-icon-btn yt-mobile-search" onclick="toggleMobileSearch()" aria-label="Search">
+                <!-- Mobile Search Icon Removed - Search will be visible -->
+                <!-- <button class="yt-icon-btn yt-mobile-search" onclick="toggleMobileSearch()" aria-label="Search">
                     <i class="fas fa-search"></i>
-                </button>
+                </button> -->
                 {% if session.get('user_id') %}
                 <div class="yt-avatar" title="{{ session.username }}">
                     {{ session.username[0]|upper }}
@@ -172,6 +169,11 @@
         <main class="yt-main" id="mainContent">
             {% block content %}{% endblock %}
         </main>
+
+        <!-- Floating Back Button (Mobile) -->
+        <button id="floatingBackBtn" class="yt-floating-back" onclick="history.back()" aria-label="Go Back">
+            <i class="fas fa-arrow-left"></i>
+        </button>
     </div>
 
     <script src="{{ url_for('static', filename='js/main.js') }}"></script>
@@ -428,17 +430,7 @@
         }
 
         // --- Back Button Logic ---
-        document.addEventListener('DOMContentLoaded', () => {
-            const path = window.location.pathname;
-            const menuBtn = document.querySelector('.yt-menu-btn');
-            const backBtnHeader = document.getElementById('headerBackBtn');
-
-            // If not home, swap menu for back
-            if (path !== '/' && backBtnHeader) {
-                if (menuBtn) menuBtn.style.display = 'none';
-                backBtnHeader.style.display = 'flex';
-            }
-        });
+        // Back Button Logic Removed (Handled Server-Side)
     </script>
     <style>
         /* Queue Drawer Styles */
diff --git a/templates/settings.html b/templates/settings.html
index 02c8fdf..5435f65 100644
--- a/templates/settings.html
+++ b/templates/settings.html
@@ -8,11 +8,11 @@
         <h3>Appearance</h3>
         <p class="yt-settings-desc">Customize how KV-Tube looks on your device.</p>
         <div class="yt-setting-row">
-            <span>Dark Mode</span>
-            <label class="yt-switch">
-                <input type="checkbox" id="themeToggle" checked onchange="toggleTheme()">
-                <span class="yt-slider round"></span>
-            </label>
+            <span>Theme Mode</span>
+            <div class="yt-theme-selector">
+                <button type="button" class="yt-theme-btn" id="themeBtnLight" onclick="setTheme('light')">Light</button>
+                <button type="button" class="yt-theme-btn" id="themeBtnDark" onclick="setTheme('dark')">Dark</button>
+            </div>
         </div>
     </div>
 
@@ -140,63 +140,36 @@
         text-align: center;
     }
 
-    /* Toggle Switch */
-    .yt-setting-row {
+    /* Theme Selector */
+    .yt-theme-selector {
         display: flex;
-        justify-content: space-between;
-        align-items: center;
-        padding: 8px 0;
-    }
-
-    .yt-switch {
-        position: relative;
-        display: inline-block;
-        width: 48px;
-        height: 24px;
-    }
-
-    .yt-switch input {
-        opacity: 0;
-        width: 0;
-        height: 0;
-    }
-
-    .yt-slider {
-        position: absolute;
-        cursor: pointer;
-        top: 0;
-        left: 0;
-        right: 0;
-        bottom: 0;
-        background-color: #666;
-        transition: .4s;
-    }
-
-    .yt-slider:before {
-        position: absolute;
-        content: "";
-        height: 18px;
-        width: 18px;
-        left: 3px;
-        bottom: 3px;
-        background-color: white;
-        transition: .4s;
-    }
-
-    input:checked+.yt-slider {
-        background-color: var(--yt-accent-blue);
-    }
-
-    input:checked+.yt-slider:before {
-        transform: translateX(24px);
-    }
-
-    .yt-slider.round {
+        gap: 12px;
+        background: var(--yt-bg-elevated);
+        padding: 4px;
         border-radius: 24px;
     }
 
-    .yt-slider.round:before {
-        border-radius: 50%;
+    .yt-theme-btn {
+        flex: 1;
+        padding: 8px 16px;
+        border-radius: 20px;
+        font-size: 14px;
+        font-weight: 500;
+        color: var(--yt-text-secondary);
+        background: transparent;
+        transition: all 0.2s;
+        border: 2px solid transparent;
+    }
+
+    .yt-theme-btn:hover {
+        color: var(--yt-text-primary);
+        background: rgba(255, 255, 255, 0.05);
+    }
+
+    .yt-theme-btn.active {
+        background: var(--yt-bg-primary);
+        color: var(--yt-text-primary);
+        box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
     }
 </style>