diff --git a/src/components/AppHeader.tsx b/src/components/AppHeader.tsx
index fc63d5c..be05d94 100644
--- a/src/components/AppHeader.tsx
+++ b/src/components/AppHeader.tsx
@@ -1,66 +1,7 @@
 import React from 'react';
-import { Link, useLocation, useParams } from 'react-router-dom';
+import { Link } from 'react-router-dom';
 
 export const AppHeader: React.FC = () => {
-  const location = useLocation();
-  const params = useParams();
-  
-  const getPageTitle = () => {
-    const { pathname } = location;
-
-    // Route patterns with titles (cleaner than manual parsing)
-    const routes = [
-      { pattern: /^\/$/,                                                      title: 'Welcome to Slideshare' },
-      { pattern: /^\/presentations$/,                                         title: 'My Presentations' },
-      { pattern: /^\/presentations\/new$/,                                    title: 'Create New Presentation' },
-      { pattern: /^\/presentations\/[^/]+\/edit\/slides\/(\d+)$/,            title: () => `Editing Slide ${params.slideNumber}` },
-      { pattern: /^\/presentations\/[^/]+\/view\/slides\/(\d+)$/,            title: () => `Viewing Slide ${params.slideNumber}` },
-      { pattern: /^\/presentations\/[^/]+\/present\/(\d+)$/,                 title: () => `Presenting Slide ${params.slideNumber}` },
-      { pattern: /^\/presentations\/[^/]+\/slide\/new\/edit$/,               title: 'Add New Slide' },
-      { pattern: /^\/presentations\/[^/]+\/slide\/[^/]+\/edit$/,             title: 'Edit Slide' },
-      { pattern: /^\/themes$/,                                               title: 'Theme Browser' },
-      { pattern: /^\/themes\/([^/]+)$/,                                      title: () => `Theme: ${params.themeId}` },
-      { pattern: /^\/themes\/[^/]+\/layouts\/([^/]+)$/,                      title: () => `Layout: ${params.layoutId}` },
-      { pattern: /^\/themes\/[^/]+\/layouts\/[^/]+\/preview$/,               title: () => `Preview Layout` },
-    ];
-
-    for (const route of routes) {
-      if (route.pattern.test(pathname)) {
-        return typeof route.title === 'function' ? route.title() : route.title;
-      }
-    }
-
-    return 'Slideshare';
-  };
-
-  const getPageDescription = () => {
-    const { pathname } = location;
-
-    // Route patterns with descriptions
-    const routes = [
-      { pattern: /^\/$/,                                                      description: 'Create beautiful presentations with customizable themes' },
-      { pattern: /^\/presentations$/,                                         description: 'View and manage all your presentations' },
-      { pattern: /^\/presentations\/new$/,                                    description: 'Enter details for your new presentation' },
-      { pattern: /^\/presentations\/[^/]+\/edit\/slides\/(\d+)$/,            description: 'Edit slide content, add notes, and manage your presentation' },
-      { pattern: /^\/presentations\/[^/]+\/view\/slides\/(\d+)$/,            description: 'View your presentation slides in read-only mode' },
-      { pattern: /^\/presentations\/[^/]+\/present\/(\d+)$/,                 description: 'Present your slides in full screen mode' },
-      { pattern: /^\/presentations\/[^/]+\/slide\/new\/edit$/,               description: 'Choose a layout and add content for your new slide' },
-      { pattern: /^\/presentations\/[^/]+\/slide\/[^/]+\/edit$/,             description: 'Edit slide content and layout' },
-      { pattern: /^\/themes$/,                                               description: 'Browse and select themes for your presentations' },
-      { pattern: /^\/themes\/([^/]+)$/,                                      description: 'View theme details, layouts, and color palette' },
-      { pattern: /^\/themes\/[^/]+\/layouts\/([^/]+)$/,                      description: 'View layout template, slots, and configuration' },
-      { pattern: /^\/themes\/[^/]+\/layouts\/[^/]+\/preview$/,               description: 'Preview layout with sample content' },
-    ];
-
-    for (const route of routes) {
-      if (route.pattern.test(pathname)) {
-        return route.description;
-      }
-    }
-
-    return 'Slide authoring and presentation tool';
-  };
-
   return (
     <header className="app-header">
       <nav className="app-nav">
@@ -82,10 +23,6 @@ export const AppHeader: React.FC = () => {
           </div>
         </div>
       </nav>
-      <div className="page-title-section">
-        <h1 className="page-title">{getPageTitle()}</h1>
-        <p className="page-description">{getPageDescription()}</p>
-      </div>
     </header>
   );
 };
\ No newline at end of file
diff --git a/src/components/presentations/NewPresentationPage.css b/src/components/presentations/NewPresentationPage.css
index b659458..2692e33 100644
--- a/src/components/presentations/NewPresentationPage.css
+++ b/src/components/presentations/NewPresentationPage.css
@@ -1,154 +1,21 @@
-.new-presentation-page {
-  min-height: 100vh;
-  background: #f8fafc;
-}
-
-.page-header {
-  background: white;
-  border-bottom: 1px solid #e2e8f0;
-  padding: 1.5rem 2rem;
-  display: flex;
-  align-items: center;
-  gap: 1.5rem;
-}
-
-.back-button {
-  background: none;
-  border: none;
-  color: #64748b;
-  font-size: 0.875rem;
-  font-weight: 500;
-  cursor: pointer;
-  padding: 0.5rem 0.75rem;
-  border-radius: 0.375rem;
-  transition: all 0.2s ease;
-}
-
-.back-button:hover {
-  background: #f1f5f9;
-  color: #334155;
-}
+/* Component uses utility classes: .page-container, .page-header, .page-content */
 
+/* Component-specific styles only */
 .header-content h1 {
-  margin: 0;
   font-size: 1.875rem;
   font-weight: 700;
-  color: #1e293b;
 }
 
-.header-content p {
-  margin: 0.25rem 0 0 0;
-  color: #64748b;
-  font-size: 0.875rem;
-}
-
-.page-content {
-  padding: 2rem;
-  max-width: 1200px;
-  margin: 0 auto;
-}
+/* Uses utility classes: .flex .flex-col .gap-8 for creation-form */
+/* Uses .card class for presentation-details, theme-selection, creation-actions */
+/* Uses .form-group, .form-label, .form-input classes from application.css */
 
 .creation-form {
-  display: flex;
-  flex-direction: column;
-  gap: 3rem;
-}
-
-/* Presentation Details Section */
-.presentation-details {
-  background: white;
-  border-radius: 0.75rem;
-  padding: 2rem;
-  border: 1px solid #e2e8f0;
-}
-
-.presentation-details h2 {
-  margin: 0 0 1.5rem 0;
-  font-size: 1.25rem;
-  font-weight: 600;
-  color: #1e293b;
-}
-
-.form-group {
-  margin-bottom: 1.5rem;
-}
-
-.form-group:last-child {
-  margin-bottom: 0;
-}
-
-.form-group label {
-  display: block;
-  margin-bottom: 0.5rem;
-  font-weight: 500;
-  color: #374151;
-  font-size: 0.875rem;
-}
-
-.form-input,
-.form-textarea {
-  width: 100%;
-  padding: 0.75rem;
-  border: 1px solid #d1d5db;
-  border-radius: 0.5rem;
-  font-size: 0.875rem;
-  transition: border-color 0.2s ease, box-shadow 0.2s ease;
-  background: white;
-  color: #374151;
-  box-sizing: border-box;
-}
-
-.form-input:focus,
-.form-textarea:focus {
-  outline: none;
-  border-color: #3b82f6;
-  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
-}
-
-.form-textarea {
-  resize: vertical;
-  min-height: 80px;
-  font-family: inherit;
-}
-
-/* Theme Selection Section */
-.theme-selection {
-  background: white;
-  border-radius: 0.75rem;
-  padding: 2rem;
-  border: 1px solid #e2e8f0;
-}
-
-.theme-selection h2 {
-  margin: 0 0 0.5rem 0;
-  font-size: 1.25rem;
-  font-weight: 600;
-  color: #1e293b;
+  gap: 3rem; /* Override default gap */
 }
 
 .section-description {
   margin: 0 0 2rem 0;
-  color: #64748b;
-  font-size: 0.875rem;
-}
-
-.no-themes {
-  text-align: center;
-  padding: 3rem;
-  color: #64748b;
-}
-
-/* Creation Actions Section */
-.creation-actions {
-  background: white;
-  border-radius: 0.75rem;
-  padding: 2rem;
-  border: 1px solid #e2e8f0;
-  display: flex;
-  justify-content: space-between;
-  align-items: center;
-  gap: 2rem;
-  flex-wrap: wrap;
 }
 
 .selected-theme-info {
@@ -160,223 +27,54 @@
   margin: 0 0 0.5rem 0;
   font-size: 1.125rem;
   font-weight: 600;
-  color: #1e293b;
+  color: var(--text-primary);
 }
 
 .theme-preview-info p {
   margin: 0 0 0.75rem 0;
-  color: #64748b;
+  color: var(--text-secondary);
   font-size: 0.875rem;
 }
 
-.theme-stats {
-  display: flex;
-  gap: 1rem;
-  font-size: 0.75rem;
-  color: #6b7280;
-}
+/* Uses .flex .gap-4 .text-xs utility classes for theme-stats */
+/* Uses .badge-secondary class for theme-stats span */
+/* Uses .alert-error class for creation-error */
 
-.theme-stats span {
-  background: #f1f5f9;
-  padding: 0.25rem 0.5rem;
-  border-radius: 0.25rem;
-}
-
-.creation-error {
-  margin-top: 1rem;
-  padding: 0.75rem;
-  background: #fef2f2;
-  border: 1px solid #fecaca;
-  border-radius: 0.375rem;
-  color: #dc2626;
-}
-
-.creation-error p {
-  margin: 0;
-  font-size: 0.875rem;
-  font-weight: 500;
-}
-
-/* Aspect Ratio Selection */
+/* Aspect Ratio Selection - uses .grid-auto-fill-250 .gap-4 */
 .aspect-ratio-selection {
   margin-bottom: 2rem;
 }
 
-.aspect-ratio-grid {
-  display: grid;
-  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
-  gap: 1rem;
-}
-
+/* Aspect ratio cards extend .card base class */
 .aspect-ratio-card {
-  border: 2px solid #e2e8f0;
-  border-radius: 0.75rem;
-  padding: 1.5rem;
+  border: 2px solid var(--border-primary);
   cursor: pointer;
-  transition: all 0.2s ease;
-  background: white;
-}
-
-.aspect-ratio-card:hover {
-  border-color: #cbd5e1;
-  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
 }
 
 .aspect-ratio-card.selected {
-  border-color: #3b82f6;
-  box-shadow: 0 4px 6px -1px rgba(59, 130, 246, 0.2);
-  background: #eff6ff;
+  border-color: var(--border-accent);
+  box-shadow: 0 4px 6px -1px var(--bg-accent);
+  background: var(--bg-accent);
 }
 
+/* Preview content - component specific */
 .aspect-ratio-preview {
-  display: flex;
-  align-items: center;
-  justify-content: center;
   height: 80px;
-  margin-bottom: 1rem;
-  background: #f8fafc;
-  border-radius: 0.5rem;
-  border: 1px dashed #cbd5e1;
+  background: var(--bg-primary);
+  border: 1px dashed var(--border-secondary);
 }
 
 .preview-box {
-  background: #3b82f6;
-  border-radius: 0.25rem;
+  background: var(--text-accent);
 }
 
-.preview-box.aspect-16-9 {
-  width: 64px;
-  height: 36px;
-}
+.preview-box.aspect-16-9 { width: 64px; height: 36px; }
+.preview-box.aspect-4-3 { width: 60px; height: 45px; }
+.preview-box.aspect-16-10 { width: 64px; height: 40px; }
 
-.preview-box.aspect-4-3 {
-  width: 60px;
-  height: 45px;
-}
+/* Uses .badge-secondary for ratio-dimensions */
+/* Uses .flex .gap-4 .flex-shrink-0 for action-buttons */
 
-.preview-box.aspect-16-10 {
-  width: 64px;
-  height: 40px;
-}
-
-.aspect-ratio-info h3 {
-  margin: 0 0 0.5rem 0;
-  font-size: 1rem;
-  font-weight: 600;
-  color: #1e293b;
-}
-
-.ratio-description {
-  margin: 0 0 0.75rem 0;
-  font-size: 0.875rem;
-  color: #64748b;
-  line-height: 1.4;
-}
-
-.ratio-dimensions {
-  font-size: 0.75rem;
-  color: #6b7280;
-  background: #f1f5f9;
-  padding: 0.25rem 0.5rem;
-  border-radius: 0.25rem;
-  display: inline-block;
-}
-
-.action-buttons {
-  display: flex;
-  gap: 1rem;
-  flex-shrink: 0;
-}
-
-.button {
-  padding: 0.75rem 1.5rem;
-  border-radius: 0.5rem;
-  font-weight: 500;
-  font-size: 0.875rem;
-  cursor: pointer;
-  transition: all 0.2s ease;
-  border: none;
-  text-decoration: none;
-  display: inline-flex;
-  align-items: center;
-  justify-content: center;
-}
-
-.button.primary {
-  background: #3b82f6;
-  color: white;
-}
-
-.button.primary:hover:not(:disabled) {
-  background: #2563eb;
-}
-
-.button.primary:disabled {
-  background: #9ca3af;
-  cursor: not-allowed;
-}
-
-.button.secondary {
-  background: #f8fafc;
-  color: #64748b;
-  border: 1px solid #e2e8f0;
-}
-
-.button.secondary:hover {
-  background: #f1f5f9;
-  color: #475569;
-}
-
-/* Loading and Error States */
-.loading-content,
-.error-content {
-  display: flex;
-  flex-direction: column;
-  align-items: center;
-  justify-content: center;
-  min-height: 50vh;
-  text-align: center;
-  gap: 1rem;
-}
-
-.loading-spinner {
-  color: #64748b;
-  font-size: 1.125rem;
-}
-
-.error-content h2 {
-  color: #dc2626;
-  margin: 0;
-}
-
-.error-content p {
-  color: #64748b;
-  margin: 0.5rem 0 1.5rem 0;
-}
-
-/* Responsive Design */
-@media (max-width: 768px) {
-  .page-header {
-    padding: 1rem;
-    flex-direction: column;
-    align-items: flex-start;
-    gap: 1rem;
-  }
-  
-  .page-content {
-    padding: 1rem;
-  }
-  
-  .creation-actions {
-    flex-direction: column;
-    align-items: stretch;
-  }
-  
-  .action-buttons {
-    justify-content: stretch;
-  }
-  
-  .button {
-    flex: 1;
-  }
-}
\ No newline at end of file
+/* Uses .btn, .btn-primary, .btn-secondary classes from application.css */
+/* Uses .loading-content, .error-content, .loading-spinner classes from application.css */
+/* Responsive design handled by utility classes in application.css */
\ No newline at end of file
diff --git a/src/components/slide-editor/SlideEditor.css b/src/components/slide-editor/SlideEditor.css
index 4b6ede5..ee6b968 100644
--- a/src/components/slide-editor/SlideEditor.css
+++ b/src/components/slide-editor/SlideEditor.css
@@ -638,7 +638,7 @@
 }
 
 .preview-info span {
-  background: rgba(0, 0, 0, 0.5);
+  background: var(--bg-overlay);
   padding: var(--space-sm) var(--space-lg);
   border-radius: var(--radius-sm);
   backdrop-filter: blur(8px);
diff --git a/src/components/ui/Modal.css b/src/components/ui/Modal.css
index d29bd40..de041ec 100644
--- a/src/components/ui/Modal.css
+++ b/src/components/ui/Modal.css
@@ -5,7 +5,7 @@
   left: 0;
   right: 0;
   bottom: 0;
-  background-color: rgba(0, 0, 0, 0.5);
+  background-color: var(--bg-overlay);
   display: flex;
   align-items: center;
   justify-content: center;
@@ -16,7 +16,7 @@
 
 /* Modal Content */
 .modal-content {
-  background: white;
+  background: var(--bg-primary);
   border-radius: 0.75rem;
   box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
   max-width: 100%;
@@ -25,6 +25,7 @@
   display: flex;
   flex-direction: column;
   animation: modalSlideIn 0.2s ease-out;
+  border: 1px solid var(--border-primary);
 }
 
 @keyframes modalSlideIn {
diff --git a/src/index.css b/src/index.css
index b9baad7..be1a9ff 100644
--- a/src/index.css
+++ b/src/index.css
@@ -1,5 +1,7 @@
 /* Import global color system */
 @import './styles/colors.css';
+/* Import consolidated application styles */
+@import './styles/application.css';
 
 :root {
   font-family: system-ui, Avenir, Helvetica, Arial, sans-serif;
diff --git a/src/styles/application.css b/src/styles/application.css
new file mode 100644
index 0000000..4a656e2
--- /dev/null
+++ b/src/styles/application.css
@@ -0,0 +1,631 @@
+/* Application CSS - Consolidated Styles */
+/* Import color system first */
+@import './colors.css';
+
+/* =================================================================
+   UTILITY CLASSES - Layout
+   ================================================================= */
+
+/* Display */
+.flex { display: flex; }
+.grid { display: grid; }
+.block { display: block; }
+.inline-block { display: inline-block; }
+.hidden { display: none; }
+
+/* Flex Direction */
+.flex-col { flex-direction: column; }
+.flex-row { flex-direction: row; }
+
+/* Flex Alignment */
+.items-start { align-items: flex-start; }
+.items-center { align-items: center; }
+.items-end { align-items: flex-end; }
+.items-stretch { align-items: stretch; }
+
+.justify-start { justify-content: flex-start; }
+.justify-center { justify-content: center; }
+.justify-end { justify-content: flex-end; }
+.justify-between { justify-content: space-between; }
+
+/* Flex Properties */
+.flex-1 { flex: 1; }
+.flex-shrink-0 { flex-shrink: 0; }
+.flex-wrap { flex-wrap: wrap; }
+
+/* Grid Templates */
+.grid-auto-fill-200 { grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); }
+.grid-auto-fill-250 { grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); }
+.grid-auto-fill-300 { grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); }
+.grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
+.grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
+
+/* Gap */
+.gap-1 { gap: 0.25rem; }
+.gap-2 { gap: 0.5rem; }
+.gap-3 { gap: 0.75rem; }
+.gap-4 { gap: 1rem; }
+.gap-6 { gap: 1.5rem; }
+.gap-8 { gap: 2rem; }
+
+/* Position */
+.relative { position: relative; }
+.absolute { position: absolute; }
+.fixed { position: fixed; }
+.sticky { position: sticky; }
+
+/* =================================================================
+   UTILITY CLASSES - Spacing
+   ================================================================= */
+
+/* Margin */
+.m-0 { margin: 0; }
+.m-auto { margin: auto; }
+.mx-auto { margin-left: auto; margin-right: auto; }
+
+.mt-1 { margin-top: 0.25rem; }
+.mt-2 { margin-top: 0.5rem; }
+.mt-4 { margin-top: 1rem; }
+.mt-6 { margin-top: 1.5rem; }
+.mt-8 { margin-top: 2rem; }
+
+.mb-1 { margin-bottom: 0.25rem; }
+.mb-2 { margin-bottom: 0.5rem; }
+.mb-4 { margin-bottom: 1rem; }
+.mb-6 { margin-bottom: 1.5rem; }
+.mb-8 { margin-bottom: 2rem; }
+
+.ml-2 { margin-left: 0.5rem; }
+.ml-4 { margin-left: 1rem; }
+.mr-2 { margin-right: 0.5rem; }
+.mr-4 { margin-right: 1rem; }
+
+/* Padding */
+.p-1 { padding: 0.25rem; }
+.p-2 { padding: 0.5rem; }
+.p-3 { padding: 0.75rem; }
+.p-4 { padding: 1rem; }
+.p-6 { padding: 1.5rem; }
+.p-8 { padding: 2rem; }
+
+.px-2 { padding-left: 0.5rem; padding-right: 0.5rem; }
+.px-3 { padding-left: 0.75rem; padding-right: 0.75rem; }
+.px-4 { padding-left: 1rem; padding-right: 1rem; }
+.px-6 { padding-left: 1.5rem; padding-right: 1.5rem; }
+.px-8 { padding-left: 2rem; padding-right: 2rem; }
+
+.py-1 { padding-top: 0.25rem; padding-bottom: 0.25rem; }
+.py-2 { padding-top: 0.5rem; padding-bottom: 0.5rem; }
+.py-3 { padding-top: 0.75rem; padding-bottom: 0.75rem; }
+.py-4 { padding-top: 1rem; padding-bottom: 1rem; }
+.py-6 { padding-top: 1.5rem; padding-bottom: 1.5rem; }
+.py-8 { padding-top: 2rem; padding-bottom: 2rem; }
+
+/* =================================================================
+   UTILITY CLASSES - Sizing
+   ================================================================= */
+
+/* Width */
+.w-full { width: 100%; }
+.w-auto { width: auto; }
+.w-8 { width: 2rem; }
+.w-12 { width: 3rem; }
+.w-16 { width: 4rem; }
+.w-32 { width: 8rem; }
+
+/* Height */
+.h-full { height: 100%; }
+.h-auto { height: auto; }
+.h-8 { height: 2rem; }
+.h-12 { height: 3rem; }
+.h-16 { height: 4rem; }
+.h-20 { height: 5rem; }
+.h-32 { height: 8rem; }
+
+/* Min/Max Width */
+.max-w-sm { max-width: 24rem; }
+.max-w-md { max-width: 28rem; }
+.max-w-lg { max-width: 32rem; }
+.max-w-xl { max-width: 36rem; }
+.max-w-2xl { max-width: 42rem; }
+.max-w-4xl { max-width: 56rem; }
+.max-w-6xl { max-width: 72rem; }
+.max-w-7xl { max-width: 80rem; }
+.max-w-full { max-width: 100%; }
+
+/* Min Height */
+.min-h-0 { min-height: 0; }
+.min-h-screen { min-height: 100vh; }
+.min-h-20 { min-height: 5rem; }
+.min-h-32 { min-height: 8rem; }
+
+/* =================================================================
+   UTILITY CLASSES - Typography
+   ================================================================= */
+
+/* Font Size */
+.text-xs { font-size: 0.75rem; line-height: 1rem; }
+.text-sm { font-size: 0.875rem; line-height: 1.25rem; }
+.text-base { font-size: 1rem; line-height: 1.5rem; }
+.text-lg { font-size: 1.125rem; line-height: 1.75rem; }
+.text-xl { font-size: 1.25rem; line-height: 1.75rem; }
+.text-2xl { font-size: 1.5rem; line-height: 2rem; }
+.text-3xl { font-size: 1.875rem; line-height: 2.25rem; }
+
+/* Font Weight */
+.font-normal { font-weight: 400; }
+.font-medium { font-weight: 500; }
+.font-semibold { font-weight: 600; }
+.font-bold { font-weight: 700; }
+
+/* Text Alignment */
+.text-left { text-align: left; }
+.text-center { text-align: center; }
+.text-right { text-align: right; }
+
+/* Line Height */
+.leading-none { line-height: 1; }
+.leading-tight { line-height: 1.25; }
+.leading-normal { line-height: 1.5; }
+.leading-relaxed { line-height: 1.625; }
+
+/* =================================================================
+   UTILITY CLASSES - Borders & Appearance
+   ================================================================= */
+
+/* Border Radius */
+.rounded { border-radius: 0.25rem; }
+.rounded-md { border-radius: 0.375rem; }
+.rounded-lg { border-radius: 0.5rem; }
+.rounded-xl { border-radius: 0.75rem; }
+.rounded-2xl { border-radius: 1rem; }
+.rounded-full { border-radius: 50%; }
+
+/* Borders */
+.border { border: 1px solid var(--border-primary); }
+.border-2 { border: 2px solid var(--border-primary); }
+.border-t { border-top: 1px solid var(--border-primary); }
+.border-b { border-bottom: 1px solid var(--border-primary); }
+.border-l { border-left: 1px solid var(--border-primary); }
+.border-r { border-right: 1px solid var(--border-primary); }
+
+.border-dashed { border-style: dashed; }
+
+/* Box Shadow */
+.shadow-none { box-shadow: none; }
+.shadow-sm { box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05); }
+.shadow { box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06); }
+.shadow-md { box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06); }
+.shadow-lg { box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05); }
+
+/* =================================================================
+   UTILITY CLASSES - Aspect Ratios
+   ================================================================= */
+
+.aspect-16-9 { aspect-ratio: 16 / 9; }
+.aspect-4-3 { aspect-ratio: 4 / 3; }
+.aspect-16-10 { aspect-ratio: 16 / 10; }
+.aspect-square { aspect-ratio: 1 / 1; }
+
+/* =================================================================
+   UTILITY CLASSES - Transitions & Animations
+   ================================================================= */
+
+.transition { transition: all 0.2s ease; }
+.transition-colors { 
+  transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease; 
+}
+.transition-opacity { transition: opacity 0.2s ease; }
+.transition-transform { transition: transform 0.2s ease; }
+
+/* Common Animation States */
+.hover\:shadow-md:hover { box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06); }
+.hover\:bg-hover:hover { background-color: var(--bg-hover); }
+
+/* =================================================================
+   UTILITY CLASSES - Interactions
+   ================================================================= */
+
+.cursor-pointer { cursor: pointer; }
+.cursor-not-allowed { cursor: not-allowed; }
+.select-none { user-select: none; }
+
+/* Opacity */
+.opacity-50 { opacity: 0.5; }
+.opacity-75 { opacity: 0.75; }
+
+/* Z-Index */
+.z-10 { z-index: 10; }
+.z-20 { z-index: 20; }
+.z-50 { z-index: 50; }
+.z-1000 { z-index: 1000; }
+
+/* =================================================================
+   COMPONENT BASE CLASSES
+   ================================================================= */
+
+/* Page Layout */
+.page-container {
+  min-height: 100vh;
+  background: var(--bg-primary);
+}
+
+.page-header {
+  background: var(--bg-secondary);
+  border-bottom: 1px solid var(--border-primary);
+  padding: 1.5rem 2rem;
+  display: flex;
+  align-items: center;
+  gap: 1.5rem;
+}
+
+.page-content {
+  padding: 2rem;
+  max-width: 1200px;
+  margin: 0 auto;
+}
+
+/* Cards */
+.card {
+  background: var(--bg-secondary);
+  border: 1px solid var(--border-primary);
+  border-radius: 0.75rem;
+  padding: 1.5rem;
+  transition: all 0.2s ease;
+}
+
+.card:hover {
+  border-color: var(--border-hover);
+  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
+}
+
+.card-compact {
+  padding: 1rem;
+}
+
+.card-header {
+  margin-bottom: 1.5rem;
+}
+
+.card-header h1,
+.card-header h2,
+.card-header h3 {
+  margin: 0 0 0.5rem 0;
+  color: var(--text-primary);
+}
+
+.card-header p {
+  margin: 0;
+  color: var(--text-secondary);
+  font-size: 0.875rem;
+}
+
+/* Grid Cards */
+.card-grid {
+  display: grid;
+  gap: 1.5rem;
+}
+
+.card-grid-auto-300 {
+  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
+}
+
+.card-grid-auto-250 {
+  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
+}
+
+/* Buttons */
+.btn {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  padding: 0.75rem 1.5rem;
+  border-radius: 0.5rem;
+  font-weight: 500;
+  font-size: 0.875rem;
+  cursor: pointer;
+  transition: all 0.2s ease;
+  text-decoration: none;
+  border: none;
+  box-sizing: border-box;
+}
+
+.btn:disabled {
+  cursor: not-allowed;
+  opacity: 0.5;
+}
+
+.btn-primary {
+  background: var(--text-accent);
+  color: white;
+}
+
+.btn-primary:hover:not(:disabled) {
+  background: var(--text-link-hover);
+}
+
+.btn-secondary {
+  background: var(--bg-primary);
+  color: var(--text-secondary);
+  border: 1px solid var(--border-primary);
+}
+
+.btn-secondary:hover:not(:disabled) {
+  background: var(--bg-hover);
+  color: var(--text-primary);
+}
+
+.btn-danger {
+  background: var(--text-error);
+  color: white;
+}
+
+.btn-danger:hover:not(:disabled) {
+  background: var(--text-error);
+  opacity: 0.9;
+}
+
+/* Button Sizes */
+.btn-sm {
+  padding: 0.5rem 1rem;
+  font-size: 0.75rem;
+}
+
+.btn-lg {
+  padding: 1rem 2rem;
+  font-size: 1rem;
+}
+
+/* Icon Buttons */
+.btn-icon {
+  padding: 0.5rem;
+  width: 2.5rem;
+  height: 2.5rem;
+  border-radius: 0.375rem;
+}
+
+.btn-icon-sm {
+  padding: 0.25rem;
+  width: 2rem;
+  height: 2rem;
+  border-radius: 0.25rem;
+}
+
+/* Form Elements */
+.form-group {
+  margin-bottom: 1.5rem;
+}
+
+.form-group:last-child {
+  margin-bottom: 0;
+}
+
+.form-label {
+  display: block;
+  margin-bottom: 0.5rem;
+  font-weight: 500;
+  color: var(--text-primary);
+  font-size: 0.875rem;
+}
+
+.form-input {
+  width: 100%;
+  padding: 0.75rem;
+  border: 1px solid var(--border-secondary);
+  border-radius: 0.5rem;
+  font-size: 0.875rem;
+  transition: border-color 0.2s ease, box-shadow 0.2s ease;
+  background: var(--bg-secondary);
+  color: var(--text-primary);
+  box-sizing: border-box;
+}
+
+.form-input:focus {
+  outline: none;
+  border-color: var(--border-accent);
+  box-shadow: 0 0 0 3px var(--bg-accent);
+}
+
+.form-textarea {
+  resize: vertical;
+  min-height: 80px;
+  font-family: inherit;
+}
+
+/* Error States */
+.form-input.error {
+  border-color: var(--border-error);
+}
+
+.form-error {
+  margin-top: 0.25rem;
+  color: var(--text-error);
+  font-size: 0.75rem;
+}
+
+/* Loading States */
+.loading-content,
+.error-content,
+.empty-content {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  min-height: 50vh;
+  text-align: center;
+  gap: 1rem;
+}
+
+.loading-spinner {
+  color: var(--text-secondary);
+  font-size: 1.125rem;
+}
+
+.error-content h2 {
+  color: var(--text-error);
+  margin: 0;
+}
+
+.error-content p {
+  color: var(--text-secondary);
+  margin: 0.5rem 0 1.5rem 0;
+}
+
+/* Alert/Notification Styles */
+.alert {
+  padding: 0.75rem;
+  border-radius: 0.375rem;
+  margin-bottom: 1rem;
+  border: 1px solid;
+}
+
+.alert-error {
+  background: var(--bg-error);
+  border-color: var(--border-error);
+  color: var(--text-error);
+}
+
+.alert-success {
+  background: var(--bg-success);
+  border-color: var(--border-success);
+  color: var(--text-success);
+}
+
+.alert-warning {
+  background: var(--bg-warning);
+  border-color: var(--border-warning);
+  color: var(--text-warning);
+}
+
+/* Modal Base */
+.modal-overlay {
+  position: fixed;
+  top: 0;
+  left: 0;
+  right: 0;
+  bottom: 0;
+  background-color: var(--bg-overlay);
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  z-index: 1000;
+  padding: 1rem;
+  box-sizing: border-box;
+}
+
+.modal-content {
+  background: var(--bg-primary);
+  border-radius: 0.75rem;
+  box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
+  max-width: 100%;
+  max-height: 90vh;
+  overflow: hidden;
+  display: flex;
+  flex-direction: column;
+  border: 1px solid var(--border-primary);
+}
+
+/* Navigation */
+.nav-link {
+  color: var(--text-secondary);
+  text-decoration: none;
+  font-weight: 500;
+  font-size: 0.875rem;
+  padding: 0.5rem 0.75rem;
+  border-radius: 0.375rem;
+  transition: all 0.2s ease;
+}
+
+.nav-link:hover {
+  background: var(--bg-hover);
+  color: var(--text-primary);
+}
+
+/* Stats/Badge Components */
+.badge {
+  padding: 0.25rem 0.75rem;
+  border-radius: 0.375rem;
+  font-size: 0.75rem;
+  font-weight: 500;
+}
+
+.badge-primary {
+  background: var(--bg-accent);
+  color: var(--text-accent);
+}
+
+.badge-secondary {
+  background: var(--bg-muted);
+  color: var(--text-tertiary);
+}
+
+/* =================================================================
+   RESPONSIVE UTILITIES
+   ================================================================= */
+
+@media (max-width: 768px) {
+  .page-header {
+    padding: 1rem;
+    flex-direction: column;
+    align-items: flex-start;
+    gap: 1rem;
+  }
+  
+  .page-content {
+    padding: 1rem;
+  }
+  
+  .card-grid-auto-300 {
+    grid-template-columns: 1fr;
+  }
+  
+  .card-grid-auto-250 {
+    grid-template-columns: 1fr;
+  }
+  
+  .flex-col-mobile {
+    flex-direction: column;
+  }
+  
+  .text-center-mobile {
+    text-align: center;
+  }
+}
+
+/* =================================================================
+   ANIMATION KEYFRAMES
+   ================================================================= */
+
+@keyframes slideIn {
+  from {
+    opacity: 0;
+    transform: scale(0.95) translateY(-10px);
+  }
+  to {
+    opacity: 1;
+    transform: scale(1) translateY(0);
+  }
+}
+
+@keyframes fadeIn {
+  from { opacity: 0; }
+  to { opacity: 1; }
+}
+
+@keyframes spin {
+  from { transform: rotate(0deg); }
+  to { transform: rotate(360deg); }
+}
+
+/* Animation utilities */
+.animate-slide-in {
+  animation: slideIn 0.2s ease-out;
+}
+
+.animate-fade-in {
+  animation: fadeIn 0.2s ease-out;
+}
+
+.animate-spin {
+  animation: spin 1s linear infinite;
+}
\ No newline at end of file
diff --git a/src/styles/colors.css b/src/styles/colors.css
index f7903a4..ee8e4c0 100644
--- a/src/styles/colors.css
+++ b/src/styles/colors.css
@@ -154,6 +154,7 @@
   --bg-muted: var(--color-gray-50);
   --bg-hover: var(--color-slate-100);
   --bg-active: var(--color-slate-200);
+  --bg-overlay: rgba(0, 0, 0, 0.5);
   
   /* Borders */
   --border-primary: var(--color-slate-200);
@@ -238,6 +239,7 @@
     --bg-muted: var(--color-gray-800);
     --bg-hover: var(--color-gray-700);
     --bg-active: var(--color-gray-600);
+    --bg-overlay: rgba(0, 0, 0, 0.7);
     
     --border-primary: var(--color-gray-600);
     --border-secondary: var(--color-gray-500);