diff --git a/electron/main.js b/electron/main.js
index e384711..7f07f4e 100644
--- a/electron/main.js
+++ b/electron/main.js
@@ -16,6 +16,8 @@ const createWindow = () => {
   mainWindow = new BrowserWindow({
     width: 1200,
     height: 800,
+    minWidth: 900,
+    minHeight: 600,
     icon: path.join(__dirname, 'toolkitIcon.png'),
     webPreferences: {
       nodeIntegration: true,
diff --git a/electron/renderer.js b/electron/renderer.js
index b18b943..f7db468 100644
--- a/electron/renderer.js
+++ b/electron/renderer.js
@@ -4,50 +4,15 @@ const path = require('path');
 // --- STATE ---
 let currentBundle = null;
 
-// --- DOM ELEMENTS ---
-// Views
-const welcomeScreen = document.getElementById('welcome-screen');
-const bundleView = document.getElementById('bundle-view');
-const createBundleForm = document.getElementById('create-bundle-form'); // This will be a modal later
-
-// Sidebar buttons
-const openBundleBtn = document.getElementById('open-bundle-btn');
-const createBundleBtn = document.getElementById('create-bundle-btn');
-
-// Bundle action buttons
-const signBundleBtn = document.getElementById('sign-bundle-btn');
-const validateBundleBtn = document.getElementById('validate-bundle-btn');
-// Fill button removed - Fill tab is now always visible
-const clearBundleBtn = document.getElementById('clear-bundle-btn');
-const saveMetadataBtn = document.getElementById('save-metadata-btn');
-
-// Save options modal elements
-const saveOptionsModal = document.getElementById('save-options-modal');
-const overwriteBundleBtn = document.getElementById('overwrite-bundle-btn');
-const saveAsNewBtn = document.getElementById('save-as-new-btn');
-
-// Signature warning modal elements
-const signatureWarningModal = document.getElementById('signature-warning-modal');
-const signatureWarningCancel = document.getElementById('signature-warning-cancel');
-const signatureWarningContinue = document.getElementById('signature-warning-continue');
-let pendingOperation = null; // Store the operation to execute after warning confirmation
-
-// Fill tab elements
-const fillTabLink = document.getElementById('fill-tab-link');
-const loadFillableTargetsBtn = document.getElementById('load-fillable-targets-btn');
-const fillLoading = document.getElementById('fill-loading');
-const fillPluginsTables = document.getElementById('fill-plugins-tables');
-const fillNoTargets = document.getElementById('fill-no-targets');
-const fillTargetsContent = document.getElementById('fill-targets-content');
-const selectAllTargetsBtn = document.getElementById('select-all-targets');
-const deselectAllTargetsBtn = document.getElementById('deselect-all-targets');
-const startFillProcessBtn = document.getElementById('start-fill-process');
-const fillProgressContainer = document.getElementById('fill-progress-container');
-const fillProgressContent = document.getElementById('fill-progress-content');
-
-// Bundle display
-const bundleTitle = document.getElementById('bundle-title');
-const manifestDetails = document.getElementById('manifest-details');
+// --- DOM ELEMENTS (will be initialized in DOMContentLoaded) ---
+let welcomeScreen, bundleView, createBundleForm;
+let openBundleBtn, createBundleBtn;
+let signBundleBtn, validateBundleBtn, clearBundleBtn, saveMetadataBtn;
+let saveOptionsModal, overwriteBundleBtn, saveAsNewBtn;
+let signatureWarningModal, signatureWarningCancel, signatureWarningContinue;
+let fillTabLink, loadFillableTargetsBtn, fillLoading, fillPluginsTables, fillNoTargets, fillTargetsContent;
+let selectAllTargetsBtn, deselectAllTargetsBtn, startFillProcessBtn, fillProgressContainer, fillProgressContent;
+let bundleTitle, manifestDetails;
 const pluginsList = document.getElementById('plugins-list');
 const validationResults = document.getElementById('validation-results');
 
@@ -79,8 +44,13 @@ let currentBundlePath = null;
 let hasUnsavedChanges = false;
 let originalMetadata = {};
 
+let pendingOperation = null; // Store the operation to execute after warning confirmation
+
 // --- INITIALIZATION ---
 document.addEventListener('DOMContentLoaded', async () => {
+  // Initialize DOM elements
+  initializeDOMElements();
+  
   // Set initial view
   showView('welcome-screen');
 
@@ -92,6 +62,50 @@ document.addEventListener('DOMContentLoaded', async () => {
   setupEventListeners();
 });
 
+function initializeDOMElements() {
+  // Views
+  welcomeScreen = document.getElementById('welcome-screen');
+  bundleView = document.getElementById('bundle-view');
+  createBundleForm = document.getElementById('create-bundle-form');
+
+  // Sidebar buttons
+  openBundleBtn = document.getElementById('open-bundle-btn');
+  createBundleBtn = document.getElementById('create-bundle-btn');
+
+  // Bundle action buttons
+  signBundleBtn = document.getElementById('sign-bundle-btn');
+  validateBundleBtn = document.getElementById('validate-bundle-btn');
+  clearBundleBtn = document.getElementById('clear-bundle-btn');
+  saveMetadataBtn = document.getElementById('save-metadata-btn');
+
+  // Save options modal elements
+  saveOptionsModal = document.getElementById('save-options-modal');
+  overwriteBundleBtn = document.getElementById('overwrite-bundle-btn');
+  saveAsNewBtn = document.getElementById('save-as-new-btn');
+
+  // Signature warning modal elements
+  signatureWarningModal = document.getElementById('signature-warning-modal');
+  signatureWarningCancel = document.getElementById('signature-warning-cancel');
+  signatureWarningContinue = document.getElementById('signature-warning-continue');
+
+  // Fill tab elements
+  fillTabLink = document.getElementById('fill-tab-link');
+  loadFillableTargetsBtn = document.getElementById('load-fillable-targets-btn');
+  fillLoading = document.getElementById('fill-loading');
+  fillPluginsTables = document.getElementById('fill-plugins-tables');
+  fillNoTargets = document.getElementById('fill-no-targets');
+  fillTargetsContent = document.getElementById('fill-targets-content');
+  selectAllTargetsBtn = document.getElementById('select-all-targets');
+  deselectAllTargetsBtn = document.getElementById('deselect-all-targets');
+  startFillProcessBtn = document.getElementById('start-fill-process');
+  fillProgressContainer = document.getElementById('fill-progress-container');
+  fillProgressContent = document.getElementById('fill-progress-content');
+
+  // Bundle display
+  bundleTitle = document.getElementById('bundle-title');
+  manifestDetails = document.getElementById('manifest-details');
+}
+
 // --- EVENT LISTENERS ---
 function setupEventListeners() {
   // Theme updates
@@ -188,6 +202,8 @@ function setupEventListeners() {
         console.log('Populating fillable targets table');
         fillTargetsContent.classList.remove('hidden');
         populateFillTargetsTable(targets);
+        // Hide the Load Available Targets button after successful load
+        loadFillableTargetsBtn.style.display = 'none';
       }
     } catch (error) {
       console.error('Error in loadFillableTargets:', error);
@@ -366,7 +382,7 @@ function setupEventListeners() {
             <td><strong>${target.triplet}</strong></td>
             <td>${target.arch}</td>
             <td><span class="target-type ${target.type}">${target.type}</span></td>
-            <td>${target.details?.compiler || 'N/A'} ${target.details?.compiler_version || ''}</td>
+            <td>${target.type === 'docker' ? 'GCC' : (target.details?.compiler || 'N/A')} ${target.details?.compiler_version || ''}</td>
           `;
           tbody.appendChild(row);
         });
@@ -516,6 +532,9 @@ async function handleOpenBundle() {
   const bundlePath = await ipcRenderer.invoke('select-file');
   if (!bundlePath) return;
 
+  // Small delay to ensure file dialog closes properly
+  await new Promise(resolve => setTimeout(resolve, 100));
+
   showSpinner();
   showModal('Opening...', `Opening bundle: ${path.basename(bundlePath)}`);
   const result = await ipcRenderer.invoke('open-bundle', bundlePath);
diff --git a/electron/styles.css b/electron/styles.css
index 2e44398..22b3f3b 100644
--- a/electron/styles.css
+++ b/electron/styles.css
@@ -9,19 +9,28 @@
 
 :root {
   --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
-  --bg-color: #f4f7fa;
-  --sidebar-bg: #ffffff;
-  --content-bg: #ffffff;
-  --text-color: #2c3e50;
-  --text-light: #7f8c8d;
-  --border-color: #e1e5e8;
-  --primary-color: #3498db;
-  --primary-hover: #2980b9;
-  --danger-color: #e74c3c;
-  --success-color: #27ae60;
-  --warning-color: #f39c12;
-  --sidebar-width: 220px;
-  --header-height: 60px;
+  --primary-color: #3b82f6;
+  --secondary-color: #1e40af;
+  --background-color: #ffffff;
+  --text-color: #1f2937;
+  --text-light: #6b7280;
+  --border-color: #e5e7eb;
+  --hover-color: #f3f4f6;
+  --sidebar-bg: #2d3748;
+  --sidebar-width: 200px;
+  
+  /* Responsive breakpoints */
+  --breakpoint-sm: 768px;
+  --breakpoint-md: 1024px;
+  --breakpoint-lg: 1280px;
+  --breakpoint-xl: 1440px;
+  
+  /* Responsive sidebar widths */
+  --primary-sidebar-collapsed: 60px;
+  --primary-sidebar-expanded: 200px;
+  --secondary-sidebar-width: 200px;
+  --secondary-sidebar-width-lg: 240px;
+  --secondary-sidebar-width-xl: 280px;
 }
 
 body.dark-mode {
@@ -47,14 +56,17 @@ body {
 .main-container {
   display: flex;
   height: 100vh;
+  min-width: 800px;
+  overflow-x: auto;
 }
 
 /* Two-Tiered Sidebar System */
 
 /* Primary Sidebar (Tier 1) - Category Bar */
 .primary-sidebar {
-  width: 60px;
-  background-color: var(--sidebar-bg);
+  width: var(--primary-sidebar-collapsed);
+  min-width: var(--primary-sidebar-collapsed);
+  background-color: #f8f9fa;
   border-right: 1px solid var(--border-color);
   display: flex;
   flex-direction: column;
@@ -64,8 +76,30 @@ body {
   z-index: 100;
 }
 
+body.dark-mode .primary-sidebar {
+  background-color: #2d3748;
+}
+
 .primary-sidebar:hover {
-  width: 200px;
+  width: var(--primary-sidebar-expanded);
+}
+
+/* Responsive primary sidebar adjustments */
+@media (max-width: 1024px) {
+  .primary-sidebar:hover {
+    width: 180px;
+  }
+}
+
+@media (max-width: 768px) {
+  .primary-sidebar {
+    width: 50px;
+    min-width: 50px;
+  }
+  
+  .primary-sidebar:hover {
+    width: 160px;
+  }
 }
 
 .primary-sidebar-header {
@@ -97,14 +131,19 @@ body {
 .star-icon {
   font-size: 18px;
   color: #3b82f6;
-  opacity: 0.9;
 }
 
 .brand-text {
-  font-size: 16px;
+  font-size: 0.9rem;
   font-weight: 700;
   color: #1f2937;
-  letter-spacing: 1px;
+  letter-spacing: 0.5px;
+  margin-left: 8px;
+  transition: color 0.2s ease;
+}
+
+body.dark-mode .primary-sidebar-header .brand-text {
+  color: #f9fafb;
 }
 
 .app-title {
@@ -179,17 +218,38 @@ body {
   padding: 12px 16px 16px 16px;
   border-top: 1px solid var(--border-color);
   display: flex;
-  flex-direction: row;
+  flex-direction: column;
   align-items: center;
-  justify-content: space-between;
+  justify-content: center;
   min-height: 40px;
+  gap: 8px;
+}
+
+/* When sidebar is collapsed, only show version centered */
+.primary-sidebar:not(:hover) .primary-sidebar-footer {
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+}
+
+/* When sidebar is expanded, show both version and info button */
+.primary-sidebar:hover .primary-sidebar-footer {
+  flex-direction: row;
+  justify-content: space-between;
+  align-items: center;
 }
 
 .version-info {
   font-size: 0.8rem;
   color: var(--text-light);
-  opacity: 0;
+  opacity: 1;
   transition: opacity 0.3s ease;
+  text-align: center;
+}
+
+/* Hide version when collapsed, show when expanded */
+.primary-sidebar:not(:hover) .version-info {
+  opacity: 1;
 }
 
 .primary-sidebar:hover .version-info {
@@ -198,16 +258,52 @@ body {
 
 /* Secondary Sidebar (Tier 2) - Content Sidebar */
 .secondary-sidebar {
-  width: var(--sidebar-width);
+  width: var(--secondary-sidebar-width);
+  min-width: var(--secondary-sidebar-width);
   background-color: #fafbfc;
   border-right: 1px solid #e5e7eb;
   display: flex;
   flex-direction: column;
   flex-shrink: 0;
-  transition: background-color 0.2s;
+  transition: all 0.2s ease;
   box-shadow: inset -1px 0 0 rgba(0, 0, 0, 0.05);
 }
 
+body.dark-mode .secondary-sidebar {
+  background-color: #374151;
+  border-right: 1px solid #4b5563;
+  box-shadow: inset -1px 0 0 rgba(255, 255, 255, 0.05);
+}
+
+/* Responsive secondary sidebar */
+@media (min-width: 1280px) {
+  .secondary-sidebar {
+    width: var(--secondary-sidebar-width-lg);
+    min-width: var(--secondary-sidebar-width-lg);
+  }
+}
+
+@media (min-width: 1440px) {
+  .secondary-sidebar {
+    width: var(--secondary-sidebar-width-xl);
+    min-width: var(--secondary-sidebar-width-xl);
+  }
+}
+
+@media (max-width: 1024px) {
+  .secondary-sidebar {
+    width: 180px;
+    min-width: 180px;
+  }
+}
+
+@media (max-width: 768px) {
+  .secondary-sidebar {
+    width: 160px;
+    min-width: 160px;
+  }
+}
+
 .sidebar-content {
   display: flex;
   flex-direction: column;
@@ -225,6 +321,12 @@ body {
   background: linear-gradient(135deg, rgba(59, 130, 246, 0.02) 0%, rgba(147, 197, 253, 0.01) 100%);
 }
 
+/* Dark mode sidebar header */
+body.dark-mode .sidebar-header {
+  border-bottom: 1px solid #4b5563;
+  background: linear-gradient(135deg, rgba(59, 130, 246, 0.05) 0%, rgba(147, 197, 253, 0.02) 100%);
+}
+
 .sidebar-header h3 {
   font-size: 1.3rem;
   font-weight: 700;
@@ -233,43 +335,66 @@ body {
   letter-spacing: -0.025em;
 }
 
+/* Dark mode sidebar header text */
+body.dark-mode .sidebar-header h3 {
+  color: #f3f4f6;
+}
+
 .sidebar-nav {
   padding: 24px 20px;
   flex-grow: 1;
 }
 
 .nav-button {
-  display: block;
   width: 100%;
   padding: 14px 20px;
   margin-bottom: 8px;
   background: white;
   border: 1px solid #e5e7eb;
-  text-align: left;
-  cursor: pointer;
   border-radius: 10px;
-  transition: all 0.2s ease;
-  font-size: 0.95rem;
-  font-weight: 500;
   color: #374151;
-  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
+  font-size: 0.9rem;
+  font-weight: 500;
+  cursor: pointer;
+  transition: all 0.2s ease;
+  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
+  text-align: left;
 }
 
 .nav-button:hover {
-  background-color: #f8fafc;
+  background: #f9fafb;
   border-color: #d1d5db;
   transform: translateY(-1px);
-  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
+  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
 }
 
 .nav-button.active {
-  background: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);
-  border-color: #2563eb;
+  background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
   color: white;
-  font-weight: 600;
+  border-color: #2563eb;
   box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
 }
 
+body.dark-mode .nav-button {
+  background: #4b5563;
+  border: 1px solid #6b7280;
+  color: #f3f4f6;
+  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
+}
+
+body.dark-mode .nav-button:hover {
+  background: #5b6572;
+  border-color: #9ca3af;
+  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.4);
+}
+
+body.dark-mode .nav-button.active {
+  background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
+  color: white;
+  border-color: #2563eb;
+  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4);
+}
+
 .nav-button.active:hover {
   transform: translateY(-1px);
   box-shadow: 0 6px 16px rgba(59, 130, 246, 0.4);
@@ -289,18 +414,36 @@ body {
   align-items: center;
   justify-content: center;
   gap: 8px;
-  background: rgba(255, 255, 255, 0.1);
-  color: white;
-  border: 1px solid rgba(255, 255, 255, 0.2);
+  background: rgba(107, 114, 128, 0.15);
+  color: #4b5563;
+  border: 1px solid rgba(107, 114, 128, 0.25);
   border-radius: 6px;
   padding: 8px 12px;
   cursor: pointer;
   font-size: 12px;
   transition: all 0.2s ease;
   width: fit-content;
+  opacity: 0;
 }
 
 .info-button:hover {
+  background: rgba(107, 114, 128, 0.2);
+  border-color: rgba(107, 114, 128, 0.35);
+}
+
+/* Show info button only when sidebar is expanded */
+.primary-sidebar:hover .info-button {
+  opacity: 1;
+}
+
+/* Dark mode info button */
+body.dark-mode .info-button {
+  background: rgba(255, 255, 255, 0.1);
+  color: white;
+  border: 1px solid rgba(255, 255, 255, 0.2);
+}
+
+body.dark-mode .info-button:hover {
   background: rgba(255, 255, 255, 0.2);
   border-color: rgba(255, 255, 255, 0.3);
 }
@@ -324,6 +467,8 @@ body {
   display: flex;
   flex-direction: column;
   overflow: hidden;
+  min-width: 0;
+  padding: 0;
 }
 
 #welcome-screen {
@@ -334,19 +479,50 @@ body {
   height: 100%;
   text-align: center;
   color: var(--text-light);
+  padding: 20px;
 }
 
 #welcome-screen h1 {
   font-size: 2rem;
-  margin-bottom: 10px;
+  margin-bottom: 0.5rem;
+  color: var(--text-color);
+}
+
+#welcome-screen p {
+  font-size: 1.1rem;
+}
+
+/* Responsive content area */
+@media (max-width: 1024px) {
+  #welcome-screen h1 {
+    font-size: 1.75rem;
+  }
+  
+  #welcome-screen p {
+    font-size: 1rem;
+  }
+}
+
+@media (max-width: 768px) {
+  #welcome-screen {
+    padding: 15px;
+  }
+  
+  #welcome-screen h1 {
+    font-size: 1.5rem;
+  }
+  
+  #welcome-screen p {
+    font-size: 0.95rem;
+  }
 }
 
 .content-header {
   display: flex;
   justify-content: space-between;
   align-items: center;
-  padding: 0 25px;
-  height: var(--header-height);
+  padding: 20px 25px;
+  min-height: 80px;
   border-bottom: 1px solid var(--border-color);
   background-color: var(--content-bg);
   flex-shrink: 0;
@@ -372,28 +548,35 @@ body {
   color: white;
 }
 
+/* Bundle View */
+#bundle-view {
+  display: flex;
+  flex-direction: column;
+  height: 100%;
+  overflow: hidden;
+}
+
 /* Tabs */
 .tab-nav {
   display: flex;
-  padding: 0 25px;
   border-bottom: 1px solid var(--border-color);
-  background-color: var(--content-bg);
+  background-color: var(--background-color);
+  overflow-x: auto;
   flex-shrink: 0;
+  padding: 0 25px;
 }
 
 .tab-link {
   padding: 15px 20px;
-  border: none;
   background: none;
+  border: none;
   cursor: pointer;
-  color: var(--text-light);
   font-size: 1rem;
+  color: var(--text-light);
   border-bottom: 3px solid transparent;
-  transition: color 0.2s, border-color 0.2s;
-}
-
-.tab-link:hover {
-  color: var(--primary-color);
+  transition: all 0.2s;
+  white-space: nowrap;
+  flex-shrink: 0;
 }
 
 .tab-link.active {
@@ -402,6 +585,49 @@ body {
   font-weight: 600;
 }
 
+.tab-link:hover {
+  color: var(--primary-color);
+}
+
+/* Dark mode tab styling */
+body.dark-mode .tab-nav {
+  background-color: #374151;
+  border-bottom: 1px solid #4b5563;
+}
+
+body.dark-mode .tab-link {
+  color: #9ca3af;
+}
+
+body.dark-mode .tab-link.active {
+  color: #f3f4f6;
+  border-bottom-color: var(--primary-color);
+}
+
+body.dark-mode .tab-link:hover {
+  color: var(--primary-color);
+}
+
+/* Responsive tabs */
+@media (max-width: 1024px) {
+  .tab-link {
+    padding: 12px 16px;
+    font-size: 0.9rem;
+  }
+}
+
+@media (max-width: 768px) {
+  .tab-link {
+    padding: 10px 12px;
+    font-size: 0.85rem;
+  }
+  
+  .tab-nav {
+    padding: 0 15px;
+    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
+  }
+}
+
 #tab-content {
   padding: 25px;
   overflow-y: auto;
@@ -464,12 +690,35 @@ body {
   height: 12px;
   border-radius: 50%;
   flex-shrink: 0;
+  display: inline-block;
 }
 
-.trust-indicator.trusted { background-color: var(--success-color); }
-.trust-indicator.untrusted { background-color: var(--danger-color); }
-.trust-indicator.unsigned { background-color: var(--warning-color); }
-.trust-indicator.warning { background-color: var(--warning-color); }
+.trust-indicator.trusted { 
+  background-color: #10b981; /* Green for trusted */
+}
+.trust-indicator.untrusted { 
+  background-color: #ef4444; /* Red for untrusted */
+}
+.trust-indicator.unsigned { 
+  background-color: #f59e0b; /* Amber for unsigned */
+}
+.trust-indicator.warning { 
+  background-color: #f59e0b; /* Amber for warning */
+}
+
+/* Dark mode trust indicators */
+body.dark-mode .trust-indicator.trusted { 
+  background-color: #34d399; /* Lighter green for dark mode */
+}
+body.dark-mode .trust-indicator.untrusted { 
+  background-color: #f87171; /* Lighter red for dark mode */
+}
+body.dark-mode .trust-indicator.unsigned { 
+  background-color: #fbbf24; /* Lighter amber for dark mode */
+}
+body.dark-mode .trust-indicator.warning { 
+  background-color: #fbbf24; /* Lighter amber for dark mode */
+}
 
 /* Plugins List */
 #plugins-list .plugin-item {
@@ -496,42 +745,94 @@ body {
     font-family: monospace;
 }
 
-/* Modal */
+/* Modal Styles */
 .modal-container {
   position: fixed;
   top: 0;
   left: 0;
   width: 100%;
   height: 100%;
-  background-color: rgba(0, 0, 0, 0.6);
+  background-color: rgba(0, 0, 0, 0.5);
   display: flex;
   justify-content: center;
   align-items: center;
   z-index: 1000;
+  padding: 20px;
 }
 
 .modal-content {
-  background-color: var(--content-bg);
-  padding: 30px;
+  background-color: white;
   border-radius: 8px;
-  min-width: 400px;
-  max-width: 600px;
-  box-shadow: 0 5px 15px rgba(0,0,0,0.3);
+  padding: 20px;
+  max-width: 500px;
+  width: 90%;
+  max-height: 80vh;
+  overflow-y: auto;
   position: relative;
+  color: #1f2937;
+}
+
+/* Dark mode modal content */
+body.dark-mode .modal-content {
+  background-color: #374151;
+  color: #f3f4f6;
+}
+
+/* Responsive modal adjustments */
+@media (max-width: 1024px) {
+  .modal-content {
+    max-width: 450px;
+    width: 95%;
+    padding: 18px;
+  }
+}
+
+@media (max-width: 768px) {
+  .modal-container {
+    padding: 15px;
+  }
+  
+  .modal-content {
+    max-width: 100%;
+    width: 100%;
+    max-height: 85vh;
+    padding: 16px;
+    border-radius: 6px;
+  }
 }
 
 .modal-close {
   position: absolute;
   top: 15px;
   right: 15px;
-  font-size: 1.5rem;
-  font-weight: bold;
+  width: 32px;
+  height: 32px;
+  border-radius: 6px;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  font-size: 1.2rem;
+  font-weight: 500;
   cursor: pointer;
-  color: var(--text-light);
+  color: #6b7280;
+  background: transparent;
+  border: none;
+  transition: all 0.2s ease;
 }
 
 .modal-close:hover {
-  color: var(--text-color);
+  color: #374151;
+  background: rgba(107, 114, 128, 0.1);
+}
+
+/* Dark mode close button */
+body.dark-mode .modal-close {
+  color: #9ca3af;
+}
+
+body.dark-mode .modal-close:hover {
+  color: #f3f4f6;
+  background: rgba(156, 163, 175, 0.1);
 }
 
 #modal-title {
@@ -694,9 +995,17 @@ body {
 }
 
 .fill-targets-table th {
-    background-color: var(--sidebar-bg);
+    background-color: #f8f9fa;
     font-weight: 600;
-    color: var(--text-color);
+    color: #374151;
+    border-bottom: 2px solid #e5e7eb;
+}
+
+/* Dark mode table headers */
+body.dark-mode .fill-targets-table th {
+    background-color: #374151;
+    color: #f3f4f6;
+    border-bottom: 2px solid #4b5563;
 }
 
 .fill-targets-table tr:last-child td {
@@ -704,7 +1013,18 @@ body {
 }
 
 .fill-targets-table tr:hover {
-    background-color: rgba(52, 152, 219, 0.05);
+    background-color: rgba(59, 130, 246, 0.05);
+}
+
+/* Dark mode table row hover */
+body.dark-mode .fill-targets-table tr:hover {
+    background-color: rgba(59, 130, 246, 0.1);
+}
+
+/* Dark mode table cells */
+body.dark-mode .fill-targets-table td {
+    color: #f3f4f6;
+    border-bottom: 1px solid #4b5563;
 }
 
 .fill-target-checkbox {
@@ -712,6 +1032,61 @@ body {
     border-color: var(--primary-hover);
 }
 
+/* Modern Action Button Base Styling */
+.action-button {
+    padding: 12px 24px;
+    border-radius: 8px;
+    font-size: 0.9rem;
+    font-weight: 500;
+    cursor: pointer;
+    transition: all 0.2s ease;
+    border: none;
+    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
+    display: inline-flex;
+    align-items: center;
+    justify-content: center;
+    gap: 8px;
+}
+
+.action-button:hover {
+    transform: translateY(-1px);
+    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
+}
+
+.action-button.primary {
+    background: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);
+    color: white;
+    border: 1px solid #2563eb;
+}
+
+.action-button.primary:hover {
+    background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
+    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
+}
+
+.action-button.secondary {
+    background: white;
+    color: #374151;
+    border: 1px solid #d1d5db;
+}
+
+.action-button.secondary:hover {
+    background: #f9fafb;
+    border-color: #9ca3af;
+}
+
+/* Dark mode action buttons */
+body.dark-mode .action-button.secondary {
+    background: #4b5563;
+    color: #f3f4f6;
+    border: 1px solid #6b7280;
+}
+
+body.dark-mode .action-button.secondary:hover {
+    background: #5b6572;
+    border-color: #9ca3af;
+}
+
 .fill-actions {
     display: flex;
     gap: 12px;
@@ -721,25 +1096,49 @@ body {
     margin-top: 20px;
 }
 
-.action-button.secondary {
-    background-color: var(--sidebar-bg);
-    color: var(--text-color);
-    border: 1px solid var(--border-color);
+/* Fill tab header with sticky blurred background */
+.fill-header {
+    position: sticky;
+    top: 0;
+    z-index: 10;
+    background: rgba(255, 255, 255, 0.9);
+    backdrop-filter: blur(10px);
+    -webkit-backdrop-filter: blur(10px);
+    border-bottom: 1px solid rgba(229, 231, 235, 0.5);
+    padding: 20px 25px;
+    margin: -25px -25px 20px -25px;
 }
 
-.action-button.secondary:hover {
-    background-color: var(--border-color);
+/* Dark mode sticky header */
+body.dark-mode .fill-header {
+    background: rgba(55, 65, 81, 0.9);
+    border-bottom: 1px solid rgba(75, 85, 99, 0.5);
 }
 
-.action-button.primary {
-    background-color: var(--primary-color);
-    color: white;
-    border: 1px solid var(--primary-color);
+.fill-header h3 {
+    margin: 0 0 8px 0;
+    font-size: 1.3rem;
+    font-weight: 600;
+    color: #1f2937;
 }
 
-.action-button.primary:hover {
-    background-color: var(--primary-hover);
-    border-color: var(--primary-hover);
+body.dark-mode .fill-header h3 {
+    color: #f3f4f6;
+}
+
+.fill-header p {
+    margin: 0 0 16px 0;
+    color: #6b7280;
+    font-size: 0.95rem;
+}
+
+body.dark-mode .fill-header p {
+    color: #9ca3af;
+}
+
+.fill-header-actions {
+    display: flex;
+    gap: 12px;
 }
 
 #fill-progress-container {
@@ -808,15 +1207,31 @@ body {
     margin-top: 2px;
 }
 
+/* Dark mode warning message */
+body.dark-mode .warning-message {
+    background-color: rgba(245, 158, 11, 0.15);
+    border: 1px solid rgba(245, 158, 11, 0.4);
+}
+
 .warning-text {
     line-height: 1.5;
     color: #92400e;
 }
 
+/* Dark mode warning text */
+body.dark-mode .warning-text {
+    color: #fbbf24;
+}
+
 .warning-text strong {
     color: #78350f;
 }
 
+/* Dark mode warning text strong */
+body.dark-mode .warning-text strong {
+    color: #f59e0b;
+}
+
 /* Save Options Modal */
 .save-options {
     display: flex;
@@ -838,30 +1253,58 @@ body {
     text-align: left;
 }
 
+/* Dark mode save option buttons */
+body.dark-mode .save-option-btn {
+    background: #4b5563;
+    border-color: #6b7280;
+}
+
 .save-option-btn:hover {
     border-color: var(--primary-color);
     background-color: rgba(52, 152, 219, 0.05);
 }
 
+/* Dark mode save option buttons hover */
+body.dark-mode .save-option-btn:hover {
+    border-color: var(--primary-color);
+    background-color: rgba(59, 130, 246, 0.15);
+}
+
 .save-option-btn.primary {
     border-color: var(--primary-color);
 }
 
+body.dark-mode .save-option-btn.primary {
+    border-color: var(--primary-color);
+}
+
 .save-option-btn.secondary {
     border-color: var(--text-light);
 }
 
+body.dark-mode .save-option-btn.secondary {
+    border-color: #9ca3af;
+}
+
 .save-option-btn strong {
     font-size: 16px;
     margin-bottom: 4px;
     color: var(--text-color);
 }
 
+body.dark-mode .save-option-btn strong {
+    color: #f3f4f6;
+}
+
 .save-option-btn small {
     font-size: 14px;
     color: var(--text-light);
 }
 
+body.dark-mode .save-option-btn small {
+    color: #d1d5db;
+}
+
 .progress-indicator.spinner-icon {
     border: 2px solid var(--text-color-light);
     border-top: 2px solid var(--primary-color);
@@ -933,6 +1376,12 @@ body {
   background-color: #f8f9fa;
 }
 
+/* Dark mode info tab nav */
+body.dark-mode .info-tab-nav {
+  background-color: #374151;
+  border-bottom: 1px solid #4b5563;
+}
+
 .info-tab-link {
   flex: 1;
   padding: 12px 16px;
@@ -945,21 +1394,45 @@ body {
   border-bottom: 2px solid transparent;
 }
 
+/* Dark mode info tab links */
+body.dark-mode .info-tab-link {
+  color: #9ca3af;
+}
+
 .info-tab-link:hover {
   background-color: #e5e7eb;
   color: #374151;
 }
 
+body.dark-mode .info-tab-link:hover {
+  background-color: #4b5563;
+  color: #f3f4f6;
+}
+
 .info-tab-link.active {
   color: #3b82f6;
   border-bottom-color: #3b82f6;
   background-color: white;
 }
 
+body.dark-mode .info-tab-link.active {
+  color: #3b82f6;
+  border-bottom-color: #3b82f6;
+  background-color: #4b5563;
+}
+
 .info-tab-content {
   padding: 24px;
   max-height: 400px;
   overflow-y: auto;
+  background-color: white;
+  color: #1f2937;
+}
+
+/* Dark mode info tab content */
+body.dark-mode .info-tab-content {
+  background-color: #374151;
+  color: #f3f4f6;
 }
 
 .info-tab-pane {
@@ -977,6 +1450,10 @@ body {
   font-size: 1.25rem;
 }
 
+body.dark-mode .info-tab-pane h4 {
+  color: #f3f4f6;
+}
+
 .info-tab-pane h5 {
   margin-top: 20px;
   margin-bottom: 12px;
@@ -984,6 +1461,32 @@ body {
   font-size: 1rem;
 }
 
+body.dark-mode .info-tab-pane h5 {
+  color: #d1d5db;
+}
+
+.info-tab-pane p {
+  color: #6b7280;
+  line-height: 1.6;
+}
+
+body.dark-mode .info-tab-pane p {
+  color: #9ca3af;
+}
+
+.info-tab-pane a {
+  color: #3b82f6;
+  text-decoration: none;
+}
+
+.info-tab-pane a:hover {
+  text-decoration: underline;
+}
+
+body.dark-mode .info-tab-pane a {
+  color: #60a5fa;
+}
+
 .info-tab-pane p {
   margin-bottom: 12px;
   line-height: 1.6;