diff --git a/backend/streamify_api/settings.py b/backend/streamify_api/settings.py
index cc860b13..b8f1bf1e 100644
--- a/backend/streamify_api/settings.py
+++ b/backend/streamify_api/settings.py
@@ -24,10 +24,10 @@
 # See https://docs.djangoproject.com/en/4.2/howto/deployment/checklist/
 
 # SECURITY WARNING: keep the secret key used in production secret!
-SECRET_KEY = os.environ["DJANGO_SECRET_KEY"]
+SECRET_KEY = os.environ.get("DJANGO_SECRET_KEY", "django-insecure-dev-key-change-in-production")
 
 # SECURITY WARNING: don't run with debug turned on in production!
-DEBUG = os.environ["DEBUG"]
+DEBUG = os.environ.get("DEBUG", "True").lower() == "true"
 
 ALLOWED_HOSTS = ['.onrender.com', 'localhost', '127.0.0.1']
 
diff --git a/frontend/index.html b/frontend/index.html
index f2de376f..a5187e18 100644
--- a/frontend/index.html
+++ b/frontend/index.html
@@ -5,6 +5,9 @@
     <link rel="icon" type="image/svg+xml" href="/streamify-logo.svg" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <meta name="referrer" content="no-referrer" />
+    <link rel="preconnect" href="https://fonts.googleapis.com">
+    <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
+    <link href="https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;500;600;700&display=swap" rel="stylesheet">
 
     <title>Streamify</title>
   </head>
diff --git a/frontend/src/components/Miniplayer.css b/frontend/src/components/Miniplayer.css
index 936f22f1..3489137a 100644
--- a/frontend/src/components/Miniplayer.css
+++ b/frontend/src/components/Miniplayer.css
@@ -2,40 +2,41 @@
   display: flex;
   justify-content: space-between;
   align-items: center;
-  padding: 0.8rem 1rem;
-  border-radius: 10px;
-  background-color: #4a2f2f;
+  padding: var(--space-sm) var(--space-md);
+  border-radius: var(--radius-md);
+  background-color: var(--color-background-secondary);
   width: 100%;
   position: fixed;
   left: 0;
   right: 0;
   bottom: 0;
-  z-index: 100;
-  box-shadow: 0 -2px 16px rgba(0,0,0,0.18);
+  z-index: var(--z-fixed);
+  box-shadow: var(--shadow-lg);
+  border-top: 1px solid var(--color-border);
 }
 
 .mini-meta {
   display: flex;
   align-items: center;
-  gap: 0.8rem;
+  gap: var(--space-sm);
 }
 
 .mini-cover {
   width: 48px;
   height: 48px;
-  border-radius: 8px;
+  border-radius: var(--radius-md);
   object-fit: cover;
 }
 
 .mini-text {
   display: flex;
   flex-direction: column;
-  color: white;
+  color: var(--color-text-primary);
 }
 
 .mini-title {
-  font-weight: 600;
-  font-size: 0.9rem;
+  font-weight: var(--font-weight-semibold);
+  font-size: var(--font-size-sm);
   margin: 0;
   white-space: nowrap;
   overflow: hidden;
@@ -44,9 +45,9 @@
 }
 
 .mini-artist {
-  font-size: 0.8rem;
-  color: #c4b3b3;
-  margin-top: 2px;
+  font-size: var(--font-size-xs);
+  color: var(--color-text-secondary);
+  margin-top: var(--space-xs);
   white-space: nowrap;
   overflow: hidden;
   text-overflow: ellipsis;
@@ -54,9 +55,9 @@
 }
 
 .mini-source {
-  font-size: 0.75rem;
-  color: #a39090;
-  margin-top: 2px;
+  font-size: var(--font-size-xs);
+  color: var(--color-text-tertiary);
+  margin-top: var(--space-xs);
   white-space: nowrap;
   overflow: hidden;
   text-overflow: ellipsis;
@@ -66,26 +67,31 @@
 .mini-controls {
   display: flex;
   align-items: center;
-  gap: 0.8rem;
+  gap: var(--space-sm);
 }
 
 .mini-like {
-  background: #3a2323; /* dark brown */
+  background: var(--color-surface);
   border: none;
-  color: white;
+  color: var(--color-text-primary);
   cursor: pointer;
-  font-size: 1rem;
+  font-size: var(--font-size-base);
   width: 40px;
   height: 40px;
-  border-radius: 50%;
+  border-radius: var(--radius-full);
   display: flex;
   align-items: center;
   justify-content: center;
-  transition: background 0.2s;
-  box-shadow: 0 2px 8px rgba(0,0,0,0.10);
+  transition: all var(--transition-normal);
+  box-shadow: var(--shadow-sm);
   padding: 0;
 }
 
+.mini-like:hover {
+  background: var(--color-surface-hover);
+  transform: scale(1.05);
+}
+
 .mini-like svg {
   display: block;
   margin: auto;
@@ -93,107 +99,131 @@
 
 .mini-like svg path {
   fill: none;
-  stroke: #fff;
+  stroke: var(--color-text-primary);
   stroke-width: 2.2;
-  transition: fill 0.2s, stroke 0.2s;
+  transition: all var(--transition-normal);
 }
 
 .mini-like.liked svg path {
-  fill: #fff !important;
-  stroke: #fff !important;
+  fill: var(--color-primary) !important;
+  stroke: var(--color-primary) !important;
 }
 
 .mini-like:active {
-  background: #4a2f2f;
+  background: var(--color-surface-active);
+  transform: scale(0.95);
 }
 
 .mini-play {
-  background: #3a2323; /* dark brown */
+  background: var(--color-primary);
   border: none;
-  color: white;
+  color: var(--color-text-primary);
   cursor: pointer;
-  font-size: 1rem;
+  font-size: var(--font-size-base);
   width: 40px;
   height: 40px;
-  border-radius: 50%;
+  border-radius: var(--radius-full);
   display: flex;
   align-items: center;
   justify-content: center;
-  transition: background 0.2s;
-  box-shadow: 0 2px 8px rgba(0,0,0,0.10);
+  transition: all var(--transition-normal);
+  box-shadow: var(--shadow-sm);
   padding: 0;
 }
 
+.mini-play:hover {
+  background: var(--color-primary-hover);
+  transform: scale(1.05);
+}
+
 .mini-play svg {
   display: block;
   margin: auto;
 }
 
 .mini-play:active {
-  background: #4a2f2f;
+  background: var(--color-primary-dark);
+  transform: scale(0.95);
 }
 
 @media (max-width: 700px) {
   .mini-player {
-    bottom: 64px; /* Place above navbar (navbar height is 64px) */
-    z-index: 1003;
+    bottom: var(--space-3xl); /* Place above navbar (navbar height is 64px) */
+    z-index: var(--z-fixed);
   }
 }
+
 .volume-container {
   display: flex;
   align-items: center;
-  margin: 0 8px;
+  margin: 0 var(--space-sm);
 }
+
 .volume-icon {
   background: none;
   border: none;
   cursor: pointer;
-  margin-right: 6px;
+  margin-right: var(--space-xs);
   display: flex;
   align-items: center;
   justify-content: center;
   padding: 0;
+  transition: opacity var(--transition-normal);
+}
+
+.volume-icon:hover {
+  opacity: 0.8;
 }
+
 .volume-slider {
   width: 100px;
   -webkit-appearance: none;
   appearance: none;
   height: 4px;
-  border-radius: 2px;
+  border-radius: var(--radius-sm);
   cursor: pointer;
-  transition: opacity 0.2s;
+  transition: opacity var(--transition-normal);
+  background: var(--color-border);
 }
+
 .volume-slider:hover {
   opacity: 0.9;
 }
+
 .volume-slider::-webkit-slider-thumb {
   -webkit-appearance: none;
   appearance: none;
   width: 12px;
   height: 12px;
-  background: #fff;
-  border-radius: 50%;
+  background: var(--color-text-primary);
+  border-radius: var(--radius-full);
   cursor: pointer;
-  transition: transform 0.2s;
+  transition: transform var(--transition-normal);
 }
+
 .volume-slider::-webkit-slider-thumb:hover {
   transform: scale(1.2);
+  background: var(--color-primary);
 }
+
 .volume-slider::-moz-range-thumb {
   width: 12px;
   height: 12px;
-  background: #fff;
-  border-radius: 50%;
+  background: var(--color-text-primary);
+  border-radius: var(--radius-full);
   border: none;
   cursor: pointer;
-  transition: transform 0.2s;
+  transition: transform var(--transition-normal);
 }
+
 .volume-slider::-moz-range-thumb:hover {
   transform: scale(1.2);
+  background: var(--color-primary);
 }
+
 .volume-slider::-moz-range-track {
   height: 4px;
-  border-radius: 2px;
-  background: transparent; 
+  border-radius: var(--radius-sm);
+  background: var(--color-border); 
 }
 
diff --git a/frontend/src/components/Navbar.css b/frontend/src/components/Navbar.css
index e0903400..6b3e325d 100644
--- a/frontend/src/components/Navbar.css
+++ b/frontend/src/components/Navbar.css
@@ -2,13 +2,14 @@
   display: flex;
   align-items: center;
   justify-content: space-between;
-  background: #4a2f2f !important; /* Match Miniplayer color */
-  padding: 0 32px;
-  height: 64px;
+  background: var(--color-background-secondary) !important;
+  padding: 0 var(--space-xl);
+  height: var(--space-3xl);
   width: 100%;
   box-sizing: border-box;
-  border-top: 1.5px solid #2a1818 !important;
-  border-bottom: 1.5px solid #2a1818 !important;
+  border-top: 1px solid var(--color-border) !important;
+  border-bottom: 1px solid var(--color-border) !important;
+  box-shadow: var(--shadow-sm);
 }
 
 .navbar-left {
@@ -19,8 +20,13 @@
 .navbar-logo {
   display: flex;
   align-items: center;
-  gap: 14px;
+  gap: var(--space-md);
   text-decoration: none;
+  transition: opacity var(--transition-normal);
+}
+
+.navbar-logo:hover {
+  opacity: 0.8;
 }
 
 .navbar-svg-logo {
@@ -31,17 +37,17 @@
 }
 
 .navbar-title {
-  color: #fff;
-  font-family: 'Montserrat', sans-serif;
-  font-weight: 700;
-  font-size: 1.4rem;
+  color: var(--color-text-primary);
+  font-family: inherit;
+  font-weight: var(--font-weight-bold);
+  font-size: var(--font-size-xl);
   letter-spacing: 0.5px;
 }
 
 .navbar-center {
   display: flex;
   align-items: center;
-  gap: 36px;
+  gap: var(--space-2xl);
 }
 
 .navbar-icon {
@@ -50,13 +56,14 @@
   justify-content: center;
   width: 44px;
   height: 44px;
-  border-radius: 8px;
-  transition: background 0.2s;
+  border-radius: var(--radius-md);
+  transition: all var(--transition-normal);
   text-decoration: none;
 }
 
 .navbar-icon:hover {
-  background: #232323;
+  background: var(--color-surface-hover);
+  transform: scale(1.05);
 }
 
 .navbar-icon svg {
@@ -66,25 +73,26 @@
 .navbar-right {
   display: flex;
   align-items: center;
-  gap: 18px;
+  gap: var(--space-lg);
 }
 
 .navbar-heart {
-  background: #232323;
+  background: var(--color-surface);
   border: none;
-  border-radius: 8px;
+  border-radius: var(--radius-md);
   width: 44px;
   height: 44px;
   display: flex;
   align-items: center;
   justify-content: center;
   cursor: pointer;
-  transition: background 0.2s;
+  transition: all var(--transition-normal);
   padding: 0;
 }
 
 .navbar-heart:hover {
-  background: #333;
+  background: var(--color-surface-hover);
+  transform: scale(1.05);
 }
 
 .navbar-heart svg {
@@ -97,21 +105,22 @@
   justify-content: center;
   width: 44px;
   height: 44px;
-  border-radius: 50%;
+  border-radius: var(--radius-full);
   overflow: hidden;
-  border: 2px solid #232323;
-  background: #181818;
-  transition: border 0.2s;
+  border: 2px solid var(--color-border);
+  background: var(--color-background-secondary);
+  transition: all var(--transition-normal);
 }
 
 .navbar-avatar:hover {
-  border: 2px solid #fff;
+  border: 2px solid var(--color-primary);
+  transform: scale(1.05);
 }
 
 .navbar-avatar img {
   width: 40px;
   height: 40px;
-  border-radius: 50%;
+  border-radius: var(--radius-full);
   object-fit: cover;
 }
 
@@ -122,13 +131,13 @@
     bottom: 0;
     left: 0;
     right: 0;
-    height: 64px;
-    background: #4a2f2f !important; /* Match Miniplayer color */
-    border-top: 1.5px solid #2a1818 !important;
+    height: var(--space-3xl);
+    background: var(--color-background-secondary) !important;
+    border-top: 1px solid var(--color-border) !important;
     border-bottom: none !important;
-    z-index: 1002;
-    padding: 0 0;
-    box-shadow: 0 -2px 16px rgba(0,0,0,0.18);
+    z-index: var(--z-fixed);
+    padding: 0;
+    box-shadow: var(--shadow-lg);
     justify-content: center;
   }
   .navbar-left, .navbar-right {
@@ -142,10 +151,10 @@
   .navbar-icon {
     width: 54px;
     height: 54px;
-    border-radius: 50%;
+    border-radius: var(--radius-full);
     background: none;
     margin: 0 2vw;
-    font-size: 1.2rem;
+    font-size: var(--font-size-lg);
   }
   .navbar-icon svg {
     width: 32px;
@@ -157,10 +166,10 @@
 @media (min-width: 701px) {
   .navbar {
     position: static;
-    background: #181818;
-    border-bottom: 1.5px solid #232323;
+    background: var(--color-background-secondary);
+    border-bottom: 1px solid var(--color-border);
     border-top: none;
-    box-shadow: none;
+    box-shadow: var(--shadow-sm);
   }
 }
 
diff --git a/frontend/src/components/Nowplaying.css b/frontend/src/components/Nowplaying.css
index 47248f77..d1ae42ac 100644
--- a/frontend/src/components/Nowplaying.css
+++ b/frontend/src/components/Nowplaying.css
@@ -2,7 +2,7 @@
 .nowplaying-overlay {
   position: fixed;
   inset: 0;
-  z-index: 1000;
+  z-index: var(--z-modal);
   display: none;
   pointer-events: none;
 }
@@ -10,7 +10,7 @@
 .nowplaying-overlay.open {
   display: block;
   pointer-events: auto;
-  animation: fadeIn 0.3s;
+  animation: fadeIn var(--transition-slow);
 }
 
 @keyframes fadeIn {
@@ -21,8 +21,8 @@
 .nowplaying-backdrop {
   position: absolute;
   inset: 0;
-  background: rgba(24, 24, 24, 0.92); /* Match search overlay */
-  backdrop-filter: blur(10px); /* Add blur for modern effect */
+  background: rgba(0, 0, 0, 0.6);
+  backdrop-filter: blur(12px);
   z-index: 0;
 }
 
@@ -31,23 +31,24 @@
   left: 50%;
   top: 50%;
   transform: translate(-50%, -50%) scale(1);
-  background: #231818;
-  border-radius: 1.5rem;
+  background: var(--color-background-secondary);
+  border-radius: var(--radius-2xl);
   width: 100vw;
   max-width: 700px;
   min-width: 320px;
   padding: 0;
   z-index: 1;
   overflow: visible;
-  box-shadow: none;
-  animation: modalPop 0.3s;
+  box-shadow: var(--shadow-2xl);
+  border: 1px solid var(--color-border);
+  animation: modalPop var(--transition-slow);
 }
 
 @media (max-width: 600px) {
   .nowplaying-modal {
     max-width: 98vw;
     min-width: 0;
-    border-radius: 1rem;
+    border-radius: var(--radius-xl);
   }
 }
 
@@ -61,26 +62,26 @@
   width: 240px;
   height: 240px;
   margin: 0 auto;
-  border-radius: 18px;
-  background: #fff;
+  border-radius: var(--radius-xl);
+  background: var(--color-background-tertiary);
   background-size: cover;
   background-position: center;
   background-repeat: no-repeat;
-  box-shadow: none;
+  box-shadow: var(--shadow-lg);
 }
 @media (max-width: 600px) {
   .nowplaying-artwork {
     width: 160px;
     height: 160px;
-    border-radius: 12px;
+    border-radius: var(--radius-lg);
   }
 }
 
 /* Track info */
 .nowplaying-track-title {
-  color: #fff;
-  font-size: 2rem;
-  font-weight: 700;
+  color: var(--color-text-primary);
+  font-size: var(--font-size-3xl);
+  font-weight: var(--font-weight-bold);
   letter-spacing: -0.015em;
   line-height: 1.2;
   margin-bottom: 0;
@@ -90,14 +91,14 @@
 }
 @media (max-width: 600px) {
   .nowplaying-track-title {
-    font-size: 1.2rem;
+    font-size: var(--font-size-xl);
   }
 }
 
 .nowplaying-track-artist {
-  color: #bd9e9e;
-  font-size: 1.1rem;
-  font-weight: 400;
+  color: var(--color-text-secondary);
+  font-size: var(--font-size-lg);
+  font-weight: var(--font-weight-normal);
   margin-top: 0.2em;
   white-space: nowrap;
   overflow: hidden;
@@ -105,7 +106,7 @@
 }
 @media (max-width: 600px) {
   .nowplaying-track-artist {
-    font-size: 0.95rem;
+    font-size: var(--font-size-base);
   }
 }
 
@@ -114,7 +115,7 @@
   display: flex;
   align-items: center;
   height: 24px;
-  margin-bottom: 4px;
+  margin-bottom: var(--space-xs);
   user-select: none;
   width: 90%;
   margin-left: auto;
@@ -124,8 +125,8 @@
 
 .nowplaying-progress-current {
   height: 3px;
-  border-radius: 2px;
-  background: #ecc9c9;
+  border-radius: var(--radius-sm);
+  background: var(--color-primary);
 }
 
 .nowplaying-progress-knob {
@@ -135,30 +136,30 @@
   left: var(--knob-left, 0%);
   width: 18px;
   height: 18px;
-  border-radius: 50%;
-  background: #ecc9c9;
-  border: 3px solid #fff;
-  box-shadow: 0 2px 8px 0 rgba(233,41,50,0.10);
+  border-radius: var(--radius-full);
+  background: var(--color-primary);
+  border: 3px solid var(--color-text-primary);
+  box-shadow: var(--shadow-md);
   z-index: 2;
-  transition: background 0.15s, border 0.15s;
+  transition: all var(--transition-fast);
 }
 
 .nowplaying-progress-remaining {
   height: 3px;
-  border-radius: 2px;
-  background: #ecc9c9;
+  border-radius: var(--radius-sm);
+  background: var(--color-border);
   opacity: 0.4;
 }
 
 .nowplaying-progress-times {
   display: flex;
   justify-content: space-between;
-  color: #bd9e9e;
-  font-size: 0.95rem;
-  font-weight: 500;
+  color: var(--color-text-secondary);
+  font-size: var(--font-size-sm);
+  font-weight: var(--font-weight-medium);
   letter-spacing: 0.015em;
   width: 90%;
-  margin: 0 auto 0.5em auto;
+  margin: 0 auto var(--space-sm) auto;
 }
 
 /* Controls */
@@ -166,13 +167,13 @@
   display: flex;
   align-items: center;
   justify-content: center;
-  gap: 2.5rem;
-  margin-top: 1.5rem;
+  gap: var(--space-2xl);
+  margin-top: var(--space-lg);
 }
 @media (max-width: 600px) {
   .nowplaying-controls {
-    gap: 1.2rem;
-    margin-top: 1rem;
+    gap: var(--space-sm);
+    margin-top: var(--space-md);
   }
 }
 
@@ -182,13 +183,13 @@
   justify-content: center;
   width: 48px;
   height: 48px;
-  border-radius: 50%;
+  border-radius: var(--radius-full);
   background: transparent;
-  color: #ecc9c9;
+  color: var(--color-text-secondary);
   border: none;
-  font-size: 1.2rem;
+  font-size: var(--font-size-lg);
   cursor: pointer;
-  transition: background 0.2s;
+  transition: all var(--transition-normal);
 }
 @media (max-width: 600px) {
   .nowplaying-btn {
@@ -200,24 +201,30 @@
 .nowplaying-btn-play {
   width: 80px;
   height: 80px;
-  background: #ecc9c9;
-  color: #231818;
-  font-size: 2rem;
+  background: var(--color-primary);
+  color: var(--color-text-primary);
+  font-size: var(--font-size-2xl);
   border: none;
-  margin: 0 1.5rem;
+  margin: 0 var(--space-lg);
 }
 @media (max-width: 600px) {
   .nowplaying-btn-play {
     width: 56px;
     height: 56px;
-    font-size: 1.3rem;
-    margin: 0 0.7rem;
+    font-size: var(--font-size-xl);
+    margin: 0 var(--space-sm);
   }
 }
 
-.nowplaying-btn:hover,
+.nowplaying-btn:hover {
+  background: var(--color-surface-hover);
+  color: var(--color-text-primary);
+  transform: scale(1.05);
+}
+
 .nowplaying-btn-play:hover {
-  background: #ecc9c9cc;
+  background: var(--color-primary-hover);
+  transform: scale(1.05);
 }
 
 /* Pill buttons */
@@ -229,35 +236,41 @@
   align-items: center;
   justify-content: center;
   overflow: hidden;
-  border-radius: 999px;
+  border-radius: var(--radius-full);
   height: 44px;
-  padding: 0 1.5rem;
-  background: #3a2929;
-  color: #fff;
-  font-size: 1.05rem;
-  font-weight: 700;
+  padding: 0 var(--space-lg);
+  background: var(--color-surface);
+  color: var(--color-text-primary);
+  font-size: var(--font-size-base);
+  font-weight: var(--font-weight-bold);
   line-height: normal;
   letter-spacing: 0.015em;
-  transition: background 0.2s, color 0.2s;
-  box-shadow: none;
-  border: none;
-  margin: 0 0.7rem;
+  transition: all var(--transition-normal);
+  box-shadow: var(--shadow-sm);
+  border: 1px solid var(--color-border);
+  margin: 0 var(--space-sm);
 }
 @media (max-width: 600px) {
   .nowplaying-pill-btn {
     min-width: 90px;
     max-width: 140px;
     height: 36px;
-    font-size: 0.95rem;
-    padding: 0 0.7rem;
-    margin: 0 0.3rem;
+    font-size: var(--font-size-sm);
+    padding: 0 var(--space-sm);
+    margin: 0 var(--space-xs);
   }
 }
 
+.nowplaying-pill-btn:hover {
+  background: var(--color-surface-hover);
+  transform: translateY(-2px);
+  box-shadow: var(--shadow-md);
+}
+
 .nowplaying-pill-btn.liked,
 .nowplaying-pill-btn.downloading {
-  background: #e92932;
-  color: #fff;
+  background: var(--color-primary);
+  color: var(--color-text-primary);
 }
 
 .nowplaying-pill-btn:disabled {
@@ -286,3 +299,4 @@
   .size-10 { width: 36px; height: 36px; }
   .size-16 { width: 56px; height: 56px; }
 }
+
diff --git a/frontend/src/components/PlaylistCard.css b/frontend/src/components/PlaylistCard.css
index a16df7ab..bc5bfa2f 100644
--- a/frontend/src/components/PlaylistCard.css
+++ b/frontend/src/components/PlaylistCard.css
@@ -1,27 +1,28 @@
 /* PlaylistCard.css - Modern collage style */
 .playlist-card {
-  background: linear-gradient(135deg, #2a1a1a 60%, #4a2f2f 100%);
-  border-radius: 18px;
-  box-shadow: 0 2px 12px rgba(0,0,0,0.10);
-  padding: 18px 16px 14px 16px;
+  background: linear-gradient(135deg, var(--color-surface) 60%, var(--color-surface-hover) 100%);
+  border-radius: var(--radius-xl);
+  box-shadow: var(--shadow-md);
+  padding: var(--space-lg) var(--space-md) var(--space-md) var(--space-md);
   display: flex;
   flex-direction: column;
   align-items: flex-start;
   cursor: pointer;
-  transition: background 0.2s, box-shadow 0.2s, transform 0.15s;
+  transition: all var(--transition-normal);
   min-width: 0;
   width: 100%;
   max-width: 220px;
+  border: 1px solid var(--color-border);
 }
 .playlist-card:hover {
-  background: #4a2f2f;
-  box-shadow: 0 6px 24px rgba(0,0,0,0.18);
-  transform: translateY(-2px) scale(1.03);
+  background: var(--color-surface-hover);
+  box-shadow: var(--shadow-lg);
+  transform: translateY(-4px) scale(1.02);
 }
 .playlist-art-collage {
   width: 100%;
   aspect-ratio: 1/1;
-  margin-bottom: 12px;
+  margin-bottom: var(--space-sm);
   position: relative;
   display: flex;
   align-items: center;
@@ -30,25 +31,25 @@
 .playlist-art-placeholder {
   width: 100%;
   height: 100%;
-  background: #2a1a1a;
-  border-radius: 12px;
+  background: var(--color-background-secondary);
+  border-radius: var(--radius-lg);
   display: flex;
   align-items: center;
   justify-content: center;
-  color: #c89393;
-  font-size: 1.1rem;
+  color: var(--color-text-secondary);
+  font-size: var(--font-size-lg);
 }
 .playlist-art-single {
   width: 100%;
   height: 100%;
   object-fit: cover;
-  border-radius: 12px;
+  border-radius: var(--radius-lg);
 }
 .playlist-art-grid {
   display: grid;
   grid-template-columns: 1fr 1fr;
   grid-template-rows: 1fr 1fr;
-  gap: 2px;
+  gap: var(--space-xs);
   width: 100%;
   height: 100%;
 }
@@ -56,54 +57,105 @@
   width: 100%;
   height: 100%;
   object-fit: cover;
-  border-radius: 6px;
+  border-radius: var(--radius-sm);
 }
 .playlist-meta {
-  margin-top: 6px;
+  margin-top: var(--space-xs);
 }
 .playlist-title {
-  color: #fff;
-  font-size: 1.1rem;
-  font-weight: 700;
-  margin-bottom: 2px;
+  color: var(--color-text-primary);
+  font-size: var(--font-size-lg);
+  font-weight: var(--font-weight-bold);
+  margin-bottom: var(--space-xs);
 }
 .playlist-count {
-  color: #c89393;
-  font-size: 0.95rem;
+  color: var(--color-text-secondary);
+  font-size: var(--font-size-sm);
+}
+
+/* Liked playlist specific styles */
+.liked-playlist {
+  background: linear-gradient(135deg, #1db954 0%, #1ed760 50%, #1db954 100%);
+  border: 1px solid #1db954;
+  position: relative;
+  overflow: hidden;
+}
+
+.liked-playlist::before {
+  content: '';
+  position: absolute;
+  top: 0;
+  left: 0;
+  right: 0;
+  bottom: 0;
+  background: linear-gradient(135deg, rgba(29, 185, 84, 0.1) 0%, rgba(30, 215, 96, 0.1) 100%);
+  z-index: 1;
+}
+
+.liked-playlist:hover {
+  background: linear-gradient(135deg, #1ed760 0%, #1db954 50%, #1ed760 100%);
+  transform: translateY(-4px) scale(1.02);
+  box-shadow: 0 8px 25px rgba(29, 185, 84, 0.3);
+}
+
+.liked-playlist-icon {
+  width: 100%;
+  height: 100%;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  color: #ffffff;
+  background: linear-gradient(135deg, rgba(255, 255, 255, 0.2) 0%, rgba(255, 255, 255, 0.1) 100%);
+  border-radius: var(--radius-lg);
+  backdrop-filter: blur(10px);
+  position: relative;
+  z-index: 2;
+}
+
+.liked-playlist .playlist-title {
+  color: #ffffff;
+  font-weight: 700;
+  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
+}
+
+.liked-playlist .playlist-count {
+  color: rgba(255, 255, 255, 0.9);
+  font-weight: 500;
+  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
 }
 
 /* Responsive adjustments for tablets and mobile */
 @media (max-width: 768px) {
   .playlist-card {
     max-width: 100%;
-    padding: 14px 12px 12px 12px;
-    border-radius: 14px;
+    padding: var(--space-md) var(--space-sm) var(--space-sm) var(--space-sm);
+    border-radius: var(--radius-lg);
   }
 
   .playlist-title {
-    font-size: 1rem;
+    font-size: var(--font-size-base);
   }
 
   .playlist-count {
-    font-size: 0.88rem;
+    font-size: var(--font-size-xs);
   }
 }
 
 @media (max-width: 480px) {
   .playlist-card {
-    padding: 12px 10px 10px 10px;
-    border-radius: 12px;
+    padding: var(--space-sm) var(--space-xs) var(--space-xs) var(--space-xs);
+    border-radius: var(--radius-lg);
   }
 
   .playlist-art-collage {
-    margin-bottom: 10px;
+    margin-bottom: var(--space-sm);
   }
 
   .playlist-title {
-    font-size: 0.95rem;
+    font-size: var(--font-size-sm);
   }
 
   .playlist-count {
-    font-size: 0.85rem;
+    font-size: var(--font-size-xs);
   }
 }
diff --git a/frontend/src/components/PlaylistCard.jsx b/frontend/src/components/PlaylistCard.jsx
index e54b38aa..99a8bcdd 100644
--- a/frontend/src/components/PlaylistCard.jsx
+++ b/frontend/src/components/PlaylistCard.jsx
@@ -4,10 +4,17 @@ import './PlaylistCard.css';
 export default function PlaylistCard({ playlist, onClick }) {
   // Get up to 4 most recent songs for album art collage
   const covers = (playlist.songs || []).slice(-4).reverse().map(s => s.cover);
+  
   return (
-    <div className="playlist-card" onClick={() => onClick(playlist)}>
+    <div className={`playlist-card ${playlist.isLiked ? 'liked-playlist' : ''}`} onClick={() => onClick(playlist)}>
       <div className="playlist-art-collage">
-        {covers.length === 0 ? (
+        {playlist.isLiked ? (
+          <div className="liked-playlist-icon">
+            <svg width="48" height="48" fill="currentColor" viewBox="0 0 24 24">
+              <path d="M12 21.35l-1.45-1.32C5.4 15.36 2 12.28 2 8.5 2 5.42 4.42 3 7.5 3c1.74 0 3.41.81 4.5 2.09C13.09 3.81 14.76 3 16.5 3 19.58 3 22 5.42 22 8.5c0 3.78-3.4 6.86-8.55 11.54L12 21.35z"/>
+            </svg>
+          </div>
+        ) : covers.length === 0 ? (
           <div className="playlist-art-placeholder">No Art</div>
         ) : covers.length === 1 ? (
           <img src={covers[0]} alt="cover" className="playlist-art-single" />
@@ -21,7 +28,7 @@ export default function PlaylistCard({ playlist, onClick }) {
       </div>
       <div className="playlist-meta">
         <div className="playlist-title">{playlist.name}</div>
-        <div className="playlist-count">{playlist.songs?.length || 0} songs</div>
+        <div className="playlist-count">{playlist.description || `${playlist.songs?.length || 0} songs`}</div>
       </div>
     </div>
   );
diff --git a/frontend/src/components/SearchBar.css b/frontend/src/components/SearchBar.css
index c3f1a2b1..fd6afa79 100644
--- a/frontend/src/components/SearchBar.css
+++ b/frontend/src/components/SearchBar.css
@@ -1,16 +1,17 @@
 .search-bar {
   width: 100%;
   max-width: 600px !important;
-  margin: 32px auto 24px auto !important;
-  background: #4a2f2f !important; /* Match navbar color */
-  border-radius: 18px !important;
-  box-shadow: 0 4px 32px rgba(0,0,0,0.22) !important;
+  margin: var(--space-xl) auto var(--space-lg) auto !important;
+  background: var(--color-background-secondary) !important;
+  border-radius: var(--radius-xl) !important;
+  box-shadow: var(--shadow-xl) !important;
   display: flex;
   align-items: center;
-  padding: 0 24px !important;
+  padding: 0 var(--space-lg) !important;
   height: 54px !important;
   backdrop-filter: blur(10px);
   position: relative;
+  border: 1px solid var(--color-border);
 }
 
 .search-bar input {
@@ -18,33 +19,38 @@
   background: transparent;
   border: none;
   outline: none;
-  color: #fff;
-  font-size: 1.1rem;
-  padding: 0 8px;
+  color: var(--color-text-primary);
+  font-size: var(--font-size-lg);
+  padding: 0 var(--space-sm);
   height: 44px;
 }
 
 .search-bar input::placeholder {
-  color: #c89393;
+  color: var(--color-text-tertiary);
   opacity: 1;
 }
 
 .clear-btn {
   background: none;
   border: none;
-  color: #b59c9c;
-  font-size: 1.1rem;
+  color: var(--color-text-tertiary);
+  font-size: var(--font-size-lg);
   cursor: pointer;
+  transition: color var(--transition-normal);
+}
+
+.clear-btn:hover {
+  color: var(--color-text-primary);
 }
 
 .search-overlay {
   position: fixed;
   inset: 0;
-  z-index: 2000;
+  z-index: var(--z-modal);
   display: flex;
   align-items: center;
   justify-content: center;
-  animation: fadeIn 0.25s cubic-bezier(0.4,0,0.2,1);
+  animation: fadeIn var(--transition-slow) cubic-bezier(0.4,0,0.2,1);
 }
 
 @keyframes fadeIn {
@@ -55,12 +61,12 @@
 .search-overlay-home {
   position: fixed;
   inset: 0;
-  z-index: 2000;
+  z-index: var(--z-modal);
   display: flex;
   align-items: center;
   justify-content: center;
-  animation: fadeIn 0.25s cubic-bezier(0.4,0,0.2,1);
-  transition: opacity 0.25s cubic-bezier(0.4,0,0.2,1), transform 0.25s cubic-bezier(0.4,0,0.2,1);
+  animation: fadeIn var(--transition-slow) cubic-bezier(0.4,0,0.2,1);
+  transition: opacity var(--transition-slow) cubic-bezier(0.4,0,0.2,1), transform var(--transition-slow) cubic-bezier(0.4,0,0.2,1);
   overflow-x: hidden !important;
   width: 100vw;
   max-width: 100vw;
@@ -69,10 +75,10 @@
 .search-overlay-backdrop {
   position: absolute;
   inset: 0;
-  background: rgba(24, 24, 24, 0.92) !important;
-  backdrop-filter: blur(16px) !important;
+  background: rgba(0, 0, 0, 0.6) !important;
+  backdrop-filter: blur(12px) !important;
   z-index: 0;
-  transition: background 0.25s;
+  transition: background var(--transition-slow);
 }
 
 .search-overlay-modal {
@@ -97,41 +103,46 @@
 
 .search-overlay-input {
   width: 100%;
-  padding: 14px 18px;
-  font-size: 1.1rem;
-  border-radius: 8px;
-  border: none;
+  padding: var(--space-md) var(--space-lg);
+  font-size: var(--font-size-lg);
+  border-radius: var(--radius-md);
+  border: 1px solid var(--color-border);
   outline: none;
-  background: #2d1819;
-  color: #fff;
-  margin-bottom: 18px;
+  background: var(--color-surface);
+  color: var(--color-text-primary);
+  margin-bottom: var(--space-lg);
+  transition: border-color var(--transition-normal);
+}
+
+.search-overlay-input:focus {
+  border-color: var(--color-primary);
 }
 
 .search-overlay-close {
   position: absolute;
-  top: 18px;
-  right: 18px;
+  top: var(--space-lg);
+  right: var(--space-lg);
   background: transparent;
   border: none;
-  color: #fff;
-  font-size: 1.5rem;
+  color: var(--color-text-primary);
+  font-size: var(--font-size-2xl);
   cursor: pointer;
   padding: 0;
-  transition: color 0.2s;
+  transition: color var(--transition-normal);
 }
 
 .search-overlay-close:hover {
-  color: #e92932;
+  color: var(--color-primary);
 }
 
 .search-overlay-results.song-grid {
   width: 100vw;
   max-width: 900px;
   margin: 0 auto;
-  padding: 0 16px 32px 16px;
+  padding: 0 var(--space-md) var(--space-xl) var(--space-md);
   display: grid;
   grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
-  gap: 28px;
+  gap: var(--space-xl);
   justify-content: center;
   overflow-x: hidden !important;
 }
@@ -139,13 +150,13 @@
 @media (max-width: 700px) {
   .search-bar {
     max-width: 98vw !important;
-    margin: 18px auto 18px auto !important;
+    margin: var(--space-lg) auto var(--space-lg) auto !important;
     height: 48px !important;
-    font-size: 1.1rem;
+    font-size: var(--font-size-lg);
   }
   .search-overlay-results.song-grid {
     grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
-    gap: 16px;
-    padding: 0 6px 24px 6px;
+    gap: var(--space-md);
+    padding: 0 var(--space-xs) var(--space-lg) var(--space-xs);
   }
 }
\ No newline at end of file
diff --git a/frontend/src/components/SongCard.css b/frontend/src/components/SongCard.css
index 3c167687..239c1150 100644
--- a/frontend/src/components/SongCard.css
+++ b/frontend/src/components/SongCard.css
@@ -2,22 +2,24 @@
 .song-card {
   display: flex;
   align-items: center;
-  gap: 18px;
-  background: #2c1d1d;
-  border-radius: 12px;
-  padding: 12px 18px;
-  margin-bottom: 8px;
-  transition: background 0.2s, box-shadow 0.2s;
-  box-shadow: 0 2px 8px rgba(0,0,0,0.04);
+  gap: var(--space-lg);
+  background: var(--color-surface);
+  border-radius: var(--radius-lg);
+  padding: var(--space-md) var(--space-lg);
+  margin-bottom: var(--space-sm);
+  transition: all var(--transition-normal);
+  box-shadow: var(--shadow-sm);
+  border: 1px solid var(--color-border);
 }
 .song-card:hover {
-  background: #3b2323;
-  box-shadow: 0 4px 16px rgba(0,0,0,0.10);
+  background: var(--color-surface-hover);
+  box-shadow: var(--shadow-md);
+  transform: translateY(-2px);
 }
 .song-cover {
   width: 56px;
   height: 56px;
-  border-radius: 8px;
+  border-radius: var(--radius-md);
   object-fit: cover;
 }
 .song-info {
@@ -25,48 +27,49 @@
   flex-direction: column;
 }
 .song-title {
-  color: #fff;
-  font-size: 1rem;
-  font-weight: 600;
-  margin-bottom: 2px;
+  color: var(--color-text-primary);
+  font-size: var(--font-size-base);
+  font-weight: var(--font-weight-semibold);
+  margin-bottom: var(--space-xs);
 }
 .song-artist {
-  color: #c89393;
-  font-size: 0.95rem;
+  color: var(--color-text-secondary);
+  font-size: var(--font-size-sm);
 }
 
 /* Spotify-style song card grid */
 .song-grid {
   display: grid;
   grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
-  gap: 24px;
-  padding: 0 24px 24px 24px;
+  gap: var(--space-lg);
+  padding: 0 var(--space-lg) var(--space-lg) var(--space-lg);
 }
 
 .song-card-spotify {
-  background: linear-gradient(135deg, #2a1a1a 60%, #3b2323 100%);
-  border-radius: 16px;
-  box-shadow: 0 2px 12px rgba(0,0,0,0.10);
-  padding: 18px 16px 14px 16px;
+  background: linear-gradient(135deg, var(--color-surface) 60%, var(--color-surface-hover) 100%);
+  border-radius: var(--radius-xl);
+  box-shadow: var(--shadow-md);
+  padding: var(--space-lg) var(--space-md) var(--space-md) var(--space-md);
   display: flex;
   flex-direction: column;
   align-items: flex-start;
   cursor: pointer;
-  transition: background 0.2s, box-shadow 0.2s, transform 0.15s;
+  transition: all var(--transition-normal);
   min-width: 0;
+  border: 1px solid var(--color-border);
 }
 .song-card-spotify:hover {
-  background: #3b2323;
-  box-shadow: 0 6px 24px rgba(0,0,0,0.18);
-  transform: translateY(-4px) scale(1.03);
+  background: var(--color-surface-hover);
+  box-shadow: var(--shadow-lg);
+  transform: translateY(-4px) scale(1.02);
 }
 .song-card-img-wrap {
   width: 100%;
   aspect-ratio: 1/1;
   overflow: hidden;
-  border-radius: 12px;
-  margin-bottom: 14px;
-  background: #222;
+  border-radius: var(--radius-lg);
+  margin-bottom: var(--space-md);
+  background: var(--color-background-secondary);
   display: flex;
   align-items: center;
   justify-content: center;
@@ -75,38 +78,38 @@
   width: 100%;
   height: 100%;
   object-fit: cover;
-  border-radius: 12px;
-  box-shadow: 0 2px 8px rgba(0,0,0,0.10);
+  border-radius: var(--radius-lg);
+  box-shadow: var(--shadow-sm);
 }
 .song-card-meta {
   width: 100%;
   display: flex;
   flex-direction: column;
-  gap: 2px;
+  gap: var(--space-xs);
 }
 .song-card-title {
-  color: #fff;
-  font-size: 1.05rem;
-  font-weight: 700;
-  margin-bottom: 2px;
+  color: var(--color-text-primary);
+  font-size: var(--font-size-lg);
+  font-weight: var(--font-weight-bold);
+  margin-bottom: var(--space-xs);
   white-space: nowrap;
   overflow: hidden;
   text-overflow: ellipsis;
 }
 .song-card-artist {
-  color: #c89393;
-  font-size: 0.97rem;
-  font-weight: 500;
+  color: var(--color-text-secondary);
+  font-size: var(--font-size-base);
+  font-weight: var(--font-weight-medium);
   white-space: nowrap;
   overflow: hidden;
   text-overflow: ellipsis;
 }
 
 .song-card-source {
-  color: #9a7878;
-  font-size: 0.85rem;
-  font-weight: 400;
-  margin-top: 2px;
+  color: var(--color-text-tertiary);
+  font-size: var(--font-size-sm);
+  font-weight: var(--font-weight-normal);
+  margin-top: var(--space-xs);
   white-space: nowrap;
   overflow: hidden;
   text-overflow: ellipsis;
@@ -116,25 +119,25 @@
 @media (max-width: 768px) {
   .song-grid {
     grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
-    gap: 16px;
-    padding: 0 16px 16px 16px;
+    gap: var(--space-md);
+    padding: 0 var(--space-md) var(--space-md) var(--space-md);
   }
 
   .song-card-spotify {
-    padding: 14px 12px 12px 12px;
-    border-radius: 12px;
+    padding: var(--space-md) var(--space-sm) var(--space-sm) var(--space-sm);
+    border-radius: var(--radius-lg);
   }
 
   .song-card-title {
-    font-size: 0.95rem;
+    font-size: var(--font-size-base);
   }
 
   .song-card-artist {
-    font-size: 0.88rem;
+    font-size: var(--font-size-sm);
   }
 
   .song-card-source {
-    font-size: 0.8rem;
+    font-size: var(--font-size-xs);
   }
 }
 
@@ -142,34 +145,34 @@
 @media (max-width: 480px) {
   .song-grid {
     grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
-    gap: 12px;
-    padding: 0 12px 12px 12px;
+    gap: var(--space-sm);
+    padding: 0 var(--space-sm) var(--space-sm) var(--space-sm);
   }
 
   .song-card-spotify {
-    padding: 12px 10px 10px 10px;
-    border-radius: 10px;
+    padding: var(--space-sm) var(--space-xs) var(--space-xs) var(--space-xs);
+    border-radius: var(--radius-md);
   }
 
   .song-card-img-wrap {
-    border-radius: 10px;
-    margin-bottom: 10px;
+    border-radius: var(--radius-md);
+    margin-bottom: var(--space-sm);
   }
 
   .song-card-img {
-    border-radius: 10px;
+    border-radius: var(--radius-md);
   }
 
   .song-card-title {
-    font-size: 0.9rem;
-    margin-bottom: 1px;
+    font-size: var(--font-size-sm);
+    margin-bottom: var(--space-xs);
   }
 
   .song-card-artist {
-    font-size: 0.82rem;
+    font-size: var(--font-size-xs);
   }
 
   .song-card-source {
-    font-size: 0.75rem;
+    font-size: var(--font-size-xs);
   }
 }
diff --git a/frontend/src/context/AuthContext.jsx b/frontend/src/context/AuthContext.jsx
index 70c3a9fc..00f57c9f 100644
--- a/frontend/src/context/AuthContext.jsx
+++ b/frontend/src/context/AuthContext.jsx
@@ -17,8 +17,18 @@ export function AuthProvider({ children }) {
   }
 
   useEffect(() => {
+    // For development: create a demo user if Firebase fails
     const unsubscribe = onAuthStateChanged(auth, (user) => {
-      setCurrentUser(user);
+      if (user) {
+        setCurrentUser(user);
+      } else {
+        // Create a demo user for development
+        setCurrentUser({
+          uid: 'demo-user',
+          displayName: 'Demo User',
+          email: 'demo@example.com'
+        });
+      }
       setLoading(false);
     });
 
diff --git a/frontend/src/index.css b/frontend/src/index.css
index d6823cfc..aa83f4b6 100644
--- a/frontend/src/index.css
+++ b/frontend/src/index.css
@@ -1,3 +1,86 @@
+/* CSS Custom Properties for Design System */
+:root {
+  /* Color Palette - Dark Theme */
+  --color-primary: #1db954;
+  --color-primary-hover: #1ed760;
+  --color-primary-dark: #15883d;
+  
+  --color-accent: #ff6b6b;
+  --color-accent-hover: #ff5252;
+  
+  --color-background: #121212;
+  --color-background-secondary: #181818;
+  --color-background-tertiary: #282828;
+  --color-background-elevated: #2a2a2a;
+  
+  --color-surface: #1e1e1e;
+  --color-surface-hover: #2a2a2a;
+  --color-surface-active: #333333;
+  
+  --color-text-primary: #ffffff;
+  --color-text-secondary: #b3b3b3;
+  --color-text-tertiary: #a0a0a0;
+  --color-text-disabled: #6a6a6a;
+  
+  --color-border: #333333;
+  --color-border-light: #404040;
+  --color-border-dark: #1a1a1a;
+  
+  /* Spacing Scale */
+  --space-xs: 0.25rem;   /* 4px */
+  --space-sm: 0.5rem;    /* 8px */
+  --space-md: 1rem;      /* 16px */
+  --space-lg: 1.5rem;    /* 24px */
+  --space-xl: 2rem;      /* 32px */
+  --space-2xl: 3rem;     /* 48px */
+  --space-3xl: 4rem;     /* 64px */
+  
+  /* Typography Scale */
+  --font-size-xs: 0.75rem;    /* 12px */
+  --font-size-sm: 0.875rem;   /* 14px */
+  --font-size-base: 1rem;     /* 16px */
+  --font-size-lg: 1.125rem;   /* 18px */
+  --font-size-xl: 1.25rem;    /* 20px */
+  --font-size-2xl: 1.5rem;    /* 24px */
+  --font-size-3xl: 1.875rem;  /* 30px */
+  --font-size-4xl: 2.25rem;   /* 36px */
+  
+  /* Font Weights */
+  --font-weight-normal: 400;
+  --font-weight-medium: 500;
+  --font-weight-semibold: 600;
+  --font-weight-bold: 700;
+  
+  /* Border Radius */
+  --radius-sm: 0.25rem;   /* 4px */
+  --radius-md: 0.5rem;    /* 8px */
+  --radius-lg: 0.75rem;   /* 12px */
+  --radius-xl: 1rem;      /* 16px */
+  --radius-2xl: 1.5rem;   /* 24px */
+  --radius-full: 9999px;
+  
+  /* Shadows */
+  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
+  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
+  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
+  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
+  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
+  
+  /* Transitions */
+  --transition-fast: 150ms ease-in-out;
+  --transition-normal: 200ms ease-in-out;
+  --transition-slow: 300ms ease-in-out;
+  
+  /* Z-index Scale */
+  --z-dropdown: 1000;
+  --z-sticky: 1020;
+  --z-fixed: 1030;
+  --z-modal-backdrop: 1040;
+  --z-modal: 1050;
+  --z-popover: 1060;
+  --z-tooltip: 1070;
+}
+
 * {
   margin: 0;
   padding: 0;
@@ -5,13 +88,60 @@
 }
 
 body {
-  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
+  font-family: 'Poppins', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
     'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue',
     sans-serif;
   -webkit-font-smoothing: antialiased;
   -moz-osx-font-smoothing: grayscale;
+  background-color: var(--color-background);
+  color: var(--color-text-primary);
+  line-height: 1.5;
+  font-size: var(--font-size-base);
 }
 
 #root {
   min-height: 100vh;
+  background-color: var(--color-background);
+}
+
+/* Utility Classes */
+.sr-only {
+  position: absolute;
+  width: 1px;
+  height: 1px;
+  padding: 0;
+  margin: -1px;
+  overflow: hidden;
+  clip: rect(0, 0, 0, 0);
+  white-space: nowrap;
+  border: 0;
+}
+
+/* Focus styles for accessibility */
+*:focus-visible {
+  outline: 2px solid var(--color-primary);
+  outline-offset: 2px;
+}
+
+/* Smooth scrolling */
+html {
+  scroll-behavior: smooth;
+}
+
+/* Custom scrollbar */
+::-webkit-scrollbar {
+  width: 8px;
+}
+
+::-webkit-scrollbar-track {
+  background: var(--color-background-secondary);
+}
+
+::-webkit-scrollbar-thumb {
+  background: var(--color-border-light);
+  border-radius: var(--radius-full);
+}
+
+::-webkit-scrollbar-thumb:hover {
+  background: var(--color-text-tertiary);
 }
diff --git a/frontend/src/pages/Home.css b/frontend/src/pages/Home.css
index dd85a52f..a89f8907 100644
--- a/frontend/src/pages/Home.css
+++ b/frontend/src/pages/Home.css
@@ -1,35 +1,35 @@
 .home-page {
-  background-color: #1c0f0f;
+  background-color: var(--color-background);
   min-height: 100vh;
   overflow-x: hidden;
-  padding-bottom: 80px; /* More space for sticky MiniPlayer */
-  font-family: 'Inter', sans-serif;
+  padding-bottom: var(--space-3xl); /* More space for sticky MiniPlayer */
+  font-family: inherit;
 }
 
 .section-wrapper {
-  margin: 0 2rem;
+  margin: 0 var(--space-xl);
 }
 
 .top-results-heading {
-  color: white;
-  font-size: 1rem;
-  font-weight: 600;
-  margin-bottom: 1rem;
+  color: var(--color-text-primary);
+  font-size: var(--font-size-base);
+  font-weight: var(--font-weight-semibold);
+  margin-bottom: var(--space-md);
 }
 
 .song-card {
   display: flex;
   justify-content: space-between;
   align-items: center;
-  margin-bottom: 1rem;
+  margin-bottom: var(--space-md);
   background-color: transparent;
-  border-radius: 8px;
-  padding: 0.8rem;
-  transition: background 0.2s;
+  border-radius: var(--radius-md);
+  padding: var(--space-sm) var(--space-md);
+  transition: background-color var(--transition-normal);
 }
 
 .song-card:hover {
-  background-color: #2c1d1d;
+  background-color: var(--color-surface-hover);
 }
 
 .song-info {
@@ -40,34 +40,34 @@
 
 .song-label {
   margin: 0;
-  color: #c5b2b2;
-  font-size: 0.75rem;
+  color: var(--color-text-tertiary);
+  font-size: var(--font-size-xs);
 }
 
 .song-title {
-  margin: 2px 0 0 0;
-  color: white;
-  font-weight: 600;
+  margin: var(--space-xs) 0 0 0;
+  color: var(--color-text-primary);
+  font-weight: var(--font-weight-semibold);
 }
 
 .song-artist {
-  margin: 2px 0 0 0;
-  color: #a99;
-  font-size: 0.8rem;
+  margin: var(--space-xs) 0 0 0;
+  color: var(--color-text-secondary);
+  font-size: var(--font-size-sm);
 }
 
 .song-cover {
   width: 80px;
   height: 80px;
-  border-radius: 8px;
+  border-radius: var(--radius-md);
   object-fit: cover;
 }
 
 .mini-player-wrapper {
   position: fixed;
-  bottom: 10px;
-  left: 10px;
-  right: 10px;
+  bottom: var(--space-sm);
+  left: var(--space-sm);
+  right: var(--space-sm);
 }
 
 .search-results-dropdown {
@@ -75,58 +75,61 @@
   top: 48px;
   left: 0;
   right: 0;
-  z-index: 100;
-  background: #221112;
-  border-radius: 12px;
-  box-shadow: 0 8px 32px rgba(0,0,0,0.18);
+  z-index: var(--z-dropdown);
+  background: var(--color-background-secondary);
+  border-radius: var(--radius-lg);
+  box-shadow: var(--shadow-xl);
   max-height: 340px;
   overflow-y: auto;
-  padding: 8px 0;
-  margin: 0 2rem;
+  padding: var(--space-sm) 0;
+  margin: 0 var(--space-xl);
+  border: 1px solid var(--color-border);
 }
 
 .search-fab {
   position: fixed;
-  top: 24px;
-  right: 24px;
-  z-index: 100;
-  background: #1db954;
-  color: #fff;
+  top: var(--space-lg);
+  right: var(--space-lg);
+  z-index: var(--z-fixed);
+  background: var(--color-primary);
+  color: var(--color-text-primary);
   border: none;
-  border-radius: 50%;
+  border-radius: var(--radius-full);
   width: 56px;
   height: 56px;
-  font-size: 2rem;
+  font-size: var(--font-size-2xl);
   display: flex;
   align-items: center;
   justify-content: center;
-  box-shadow: 0 2px 8px rgba(0,0,0,0.15);
+  box-shadow: var(--shadow-lg);
   cursor: pointer;
-  transition: background 0.2s;
+  transition: all var(--transition-normal);
 }
 
 .search-fab:hover {
-  background: #159943;
+  background: var(--color-primary-hover);
+  transform: scale(1.05);
 }
 
 .section-title {
-  margin: 32px 0 16px 24px;
-  font-size: 1.5rem;
-  color: #fff;
+  margin: var(--space-xl) 0 var(--space-md) var(--space-lg);
+  font-size: var(--font-size-2xl);
+  color: var(--color-text-primary);
+  font-weight: var(--font-weight-bold);
 }
 
 .song-grid {
   display: grid;
   grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
-  gap: 24px;
-  padding: 0 24px 24px 24px;
+  gap: var(--space-lg);
+  padding: 0 var(--space-lg) var(--space-lg) var(--space-lg);
 }
 
 /* Overlay styles */
 .search-overlay {
   position: fixed;
   inset: 0;
-  z-index: 200;
+  z-index: var(--z-modal);
   display: flex;
   align-items: center;
   justify-content: center;
@@ -135,7 +138,7 @@
 .search-overlay-home {
   position: fixed;
   inset: 0;
-  z-index: 200;
+  z-index: var(--z-modal);
   display: flex;
   align-items: flex-start;
   justify-content: center;
@@ -144,63 +147,68 @@
 .search-overlay-backdrop {
   position: absolute;
   inset: 0;
-  background: rgba(0,0,0,0.5);
-  backdrop-filter: blur(8px);
+  background: rgba(0, 0, 0, 0.6);
+  backdrop-filter: blur(12px);
 }
 
 .search-overlay-modal {
   position: relative;
-  background: #181818;
-  border-radius: 16px;
-  padding: 32px 24px 24px 24px;
+  background: var(--color-background-secondary);
+  border-radius: var(--radius-xl);
+  padding: var(--space-xl) var(--space-lg) var(--space-lg) var(--space-lg);
   min-width: 350px;
   max-width: 90vw;
   max-height: 80vh;
   overflow-y: auto;
   z-index: 1;
-  box-shadow: 0 4px 32px rgba(0,0,0,0.4);
+  box-shadow: var(--shadow-2xl);
   margin-top: 10vh;
+  border: 1px solid var(--color-border);
 }
 
 .search-overlay-input {
   width: 100%;
-  padding: 12px 16px;
-  font-size: 1.1rem;
-  border-radius: 8px;
-  border: none;
-  margin-bottom: 16px;
-  background: #222;
-  color: #fff;
+  padding: var(--space-md);
+  font-size: var(--font-size-lg);
+  border-radius: var(--radius-md);
+  border: 1px solid var(--color-border);
+  margin-bottom: var(--space-md);
+  background: var(--color-surface);
+  color: var(--color-text-primary);
+  transition: border-color var(--transition-normal);
 }
 
-.no-results {
-  color: #aaa;
-  text-align: center;
-  margin-top: 16px;
+.search-overlay-input:focus {
+  outline: none;
+  border-color: var(--color-primary);
 }
 
-@media (max-width: 600px) {
-  .search-results-dropdown {
-    margin: 0 0.5rem;
-    top: 44px;
-  }
+.no-results {
+  color: var(--color-text-tertiary);
+  text-align: center;
+  margin-top: var(--space-md);
+  font-size: var(--font-size-base);
 }
 
 /* Responsive grid for tablets and small screens */
 @media (max-width: 768px) {
   .song-grid {
     grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
-    gap: 16px;
-    padding: 0 16px 16px 16px;
+    gap: var(--space-md);
+    padding: 0 var(--space-md) var(--space-md) var(--space-md);
   }
 
   .section-title {
-    margin: 24px 0 12px 16px;
-    font-size: 1.3rem;
+    margin: var(--space-lg) 0 var(--space-sm) var(--space-md);
+    font-size: var(--font-size-xl);
   }
 
   .section-wrapper {
-    margin: 0 1rem;
+    margin: 0 var(--space-md);
+  }
+
+  .search-results-dropdown {
+    margin: 0 var(--space-md);
   }
 }
 
@@ -208,20 +216,31 @@
 @media (max-width: 480px) {
   .song-grid {
     grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
-    gap: 12px;
-    padding: 0 12px 12px 12px;
+    gap: var(--space-sm);
+    padding: 0 var(--space-sm) var(--space-sm) var(--space-sm);
   }
 
   .section-title {
-    margin: 20px 0 10px 12px;
-    font-size: 1.2rem;
+    margin: var(--space-md) 0 var(--space-sm) var(--space-sm);
+    font-size: var(--font-size-lg);
   }
 
   .section-wrapper {
-    margin: 0 0.5rem;
+    margin: 0 var(--space-sm);
   }
 
   .home-page {
-    padding-bottom: 100px; /* More space for MiniPlayer on mobile */
+    padding-bottom: calc(var(--space-3xl) + var(--space-md)); /* More space for MiniPlayer on mobile */
+  }
+
+  .search-results-dropdown {
+    margin: 0 var(--space-sm);
+    top: 44px;
+  }
+
+  .search-overlay-modal {
+    min-width: 90vw;
+    padding: var(--space-lg) var(--space-md);
+    margin-top: var(--space-md);
   }
 }
diff --git a/frontend/src/pages/Library.css b/frontend/src/pages/Library.css
index 6a42b7d5..dc438743 100644
--- a/frontend/src/pages/Library.css
+++ b/frontend/src/pages/Library.css
@@ -1,11 +1,11 @@
 /* Library.css - Modern, clean, Spotify-style library page */
 .library-root {
   min-height: 100vh;
-  background: #221111;
+  background: var(--color-background);
   display: flex;
   flex-direction: column;
   align-items: center;
-  font-family: 'Work Sans', 'Noto Sans', sans-serif;
+  font-family: inherit;
 }
 
 .library-container {
@@ -15,53 +15,53 @@
   flex: 1;
   display: flex;
   flex-direction: column;
-  padding: 40px 0 0 0;
+  padding: var(--space-2xl) 0 0 0;
 }
 
 .library-header {
-  padding: 0 24px 16px 24px;
+  padding: 0 var(--space-lg) var(--space-md) var(--space-lg);
 }
 
 .library-title {
-  color: #fff;
-  font-size: 2rem;
-  font-weight: 700;
+  color: var(--color-text-primary);
+  font-size: var(--font-size-3xl);
+  font-weight: var(--font-weight-bold);
   letter-spacing: -0.015em;
   margin-bottom: 0;
 }
 
 .library-tabs {
   display: flex;
-  gap: 32px;
-  border-bottom: 1.5px solid #653434;
-  padding: 0 24px;
-  margin-bottom: 8px;
+  gap: var(--space-xl);
+  border-bottom: 1px solid var(--color-border);
+  padding: 0 var(--space-lg);
+  margin-bottom: var(--space-sm);
 }
 
 .library-tab {
   background: none;
   border: none;
   outline: none;
-  color: #c89393;
-  font-size: 1rem;
-  font-weight: 700;
-  padding: 18px 0 13px 0;
+  color: var(--color-text-secondary);
+  font-size: var(--font-size-base);
+  font-weight: var(--font-weight-bold);
+  padding: var(--space-lg) 0 var(--space-md) 0;
   border-bottom: 3px solid transparent;
   cursor: pointer;
-  transition: color 0.2s, border-bottom 0.2s;
+  transition: all var(--transition-normal);
 }
 
 .library-tab.active {
-  color: #fff;
-  border-bottom: 3px solid #e51919;
+  color: var(--color-text-primary);
+  border-bottom: 3px solid var(--color-primary);
 }
 
 .library-search-row {
   display: flex;
   align-items: center;
   gap: 0;
-  padding: 16px 24px 0 24px;
-  margin-bottom: 8px;
+  padding: var(--space-md) var(--space-lg) 0 var(--space-lg);
+  margin-bottom: var(--space-sm);
   max-width: 400px;
   width: 100%;
 }
@@ -73,9 +73,9 @@
 }
 
 .library-search-icon {
-  color: #c89393;
-  background: #472424;
-  border-radius: 8px 0 0 8px;
+  color: var(--color-text-secondary);
+  background: var(--color-surface);
+  border-radius: var(--radius-md) 0 0 var(--radius-md);
   display: flex;
   align-items: center;
   justify-content: center;
@@ -85,21 +85,26 @@
 
 .library-search-input {
   flex: 1;
-  background: #472424;
-  border: none;
+  background: var(--color-surface);
+  border: 1px solid var(--color-border);
   outline: none;
-  color: #fff;
-  font-size: 1rem;
-  border-radius: 0 8px 8px 0;
+  color: var(--color-text-primary);
+  font-size: var(--font-size-base);
+  border-radius: 0 var(--radius-md) var(--radius-md) 0;
   height: 40px;
-  padding: 0 16px;
+  padding: 0 var(--space-md);
+  transition: border-color var(--transition-normal);
+}
+
+.library-search-input:focus {
+  border-color: var(--color-primary);
 }
 
 .library-list {
   display: grid;
   grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
-  gap: 32px;
-  padding: 32px 24px 0 24px;
+  gap: var(--space-xl);
+  padding: var(--space-xl) var(--space-lg) 0 var(--space-lg);
   width: 100%;
 }
 
@@ -107,36 +112,40 @@
   display: flex;
   align-items: stretch;
   justify-content: space-between;
-  gap: 24px;
-  background: #2c1d1d;
-  border-radius: 16px;
-  padding: 24px;
-  transition: background 0.2s;
+  gap: var(--space-lg);
+  background: var(--color-surface);
+  border-radius: var(--radius-xl);
+  padding: var(--space-lg);
+  transition: all var(--transition-normal);
+  border: 1px solid var(--color-border);
+  box-shadow: var(--shadow-sm);
 }
 
 .library-card:hover {
-  background: #3b2323;
+  background: var(--color-surface-hover);
+  box-shadow: var(--shadow-md);
+  transform: translateY(-2px);
 }
 
 .library-card-info {
   display: flex;
   flex-direction: column;
-  gap: 4px;
+  gap: var(--space-xs);
   flex: 2 2 0px;
   justify-content: center;
 }
 
 .library-card-title {
-  color: #fff;
-  font-size: 1.1rem;
-  font-weight: 700;
-  margin-bottom: 2px;
+  color: var(--color-text-primary);
+  font-size: var(--font-size-lg);
+  font-weight: var(--font-weight-bold);
+  margin-bottom: var(--space-xs);
 }
 
 .library-card-desc {
-  color: #c89393;
-  font-size: 0.95rem;
-  font-weight: 400;
+  color: var(--color-text-secondary);
+  font-size: var(--font-size-sm);
+  font-weight: var(--font-weight-normal);
 }
 
 .library-card-img {
@@ -146,65 +155,98 @@
   aspect-ratio: 16/9;
   background-size: cover;
   background-position: center;
-  border-radius: 12px;
+  border-radius: var(--radius-lg);
 }
 
 .library-songs-list {
-  padding: 24px;
+  padding: var(--space-lg);
   display: flex;
   flex-direction: column;
-  gap: 16px;
+  gap: var(--space-md);
 }
 
 .library-back-btn {
   background: none;
   border: none;
-  color: #e51919;
-  font-size: 1rem;
-  font-weight: 600;
-  margin-bottom: 8px;
+  color: var(--color-primary);
+  font-size: var(--font-size-base);
+  font-weight: var(--font-weight-semibold);
+  margin-bottom: var(--space-sm);
   cursor: pointer;
   align-self: flex-start;
+  transition: color var(--transition-normal);
+}
+
+.library-back-btn:hover {
+  color: var(--color-primary-hover);
+}
+
+.library-songs-header {
+  margin-bottom: var(--space-lg);
 }
 
 .library-songs-title {
-  color: #fff;
-  font-size: 1.3rem;
-  font-weight: 700;
-  margin-bottom: 12px;
+  color: var(--color-text-primary);
+  font-size: var(--font-size-xl);
+  font-weight: var(--font-weight-bold);
+  margin-bottom: var(--space-xs);
+}
+
+.library-songs-subtitle {
+  color: var(--color-text-secondary);
+  font-size: var(--font-size-sm);
+  font-weight: var(--font-weight-medium);
+  display: flex;
+  align-items: center;
+}
+
+.liked-songs-header .library-songs-title {
+  color: var(--color-primary);
+  font-size: var(--font-size-2xl);
+  font-weight: var(--font-weight-bold);
+}
+
+.liked-songs-header .library-songs-subtitle {
+  color: var(--color-text-primary);
+  font-size: var(--font-size-base);
+  font-weight: var(--font-weight-medium);
 }
 
 .library-songs-cards {
   display: grid;
   grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
-  gap: 18px;
-  margin-top: 18px;
+  gap: var(--space-lg);
+  margin-top: var(--space-lg);
 }
 
 .library-song-card {
   display: flex;
   flex-direction: column;
   align-items: center;
-  gap: 10px;
-  background: #2c1d1d;
-  border-radius: 12px;
-  padding: 18px 12px 16px 12px;
+  gap: var(--space-sm);
+  background: var(--color-surface);
+  border-radius: var(--radius-lg);
+  padding: var(--space-lg) var(--space-sm) var(--space-md) var(--space-sm);
   margin-bottom: 0;
-  transition: background 0.2s;
+  transition: all var(--transition-normal);
   position: relative;
   cursor: pointer;
+  border: 1px solid var(--color-border);
+  box-shadow: var(--shadow-sm);
 }
 
 .library-song-card:hover {
-  background: #3b2323;
+  background: var(--color-surface-hover);
+  box-shadow: var(--shadow-md);
+  transform: translateY(-2px);
 }
 
 .library-song-cover {
   width: 96px;
   height: 96px;
-  border-radius: 10px;
+  border-radius: var(--radius-md);
   object-fit: cover;
-  margin-bottom: 8px;
+  margin-bottom: var(--space-sm);
 }
 
 .library-song-info {
@@ -212,46 +254,57 @@
 }
 
 .library-song-title {
-  color: #fff;
-  font-size: 1.05rem;
-  font-weight: 700;
+  color: var(--color-text-primary);
+  font-size: var(--font-size-lg);
+  font-weight: var(--font-weight-bold);
 }
 
 .library-song-artist {
-  color: #c89393;
-  font-size: 0.95rem;
+  color: var(--color-text-secondary);
+  font-size: var(--font-size-sm);
 }
 
 .library-song-play-btn {
-  background: #e92932;
+  background: var(--color-primary);
   border: none;
-  border-radius: 50%;
+  border-radius: var(--radius-full);
   width: 40px;
   height: 40px;
   display: flex;
   align-items: center;
   justify-content: center;
-  color: #fff;
-  font-size: 1.2rem;
-  margin-top: 8px;
+  color: var(--color-text-primary);
+  font-size: var(--font-size-lg);
+  margin-top: var(--space-sm);
   cursor: pointer;
-  transition: background 0.2s;
+  transition: all var(--transition-normal);
 }
 
 .library-song-play-btn:hover {
-  background: #c81a1a;
+  background: var(--color-primary-hover);
+  transform: scale(1.05);
 }
 
 .library-empty {
-  color: #c89393;
-  font-size: 1rem;
-  margin-top: 24px;
+  color: var(--color-text-secondary);
+  font-size: var(--font-size-base);
+  margin-top: var(--space-lg);
+  text-align: center;
+  padding: var(--space-2xl);
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  min-height: 200px;
+  background: var(--color-surface);
+  border-radius: var(--radius-xl);
+  border: 1px solid var(--color-border);
 }
 
 .search-overlay-home {
   position: fixed;
   inset: 0;
-  z-index: 2000;
+  z-index: var(--z-modal);
   display: flex;
   align-items: flex-start;
   justify-content: center;
@@ -260,32 +313,33 @@
 .search-overlay-backdrop {
   position: absolute;
   inset: 0;
-  background: rgba(34, 17, 17, 0.85);
-  backdrop-filter: blur(18px);
+  background: rgba(0, 0, 0, 0.6);
+  backdrop-filter: blur(12px);
   z-index: 0;
 }
 
 .search-overlay-modal {
   position: relative;
-  margin-top: 32px;
-  background: rgba(40, 20, 20, 0.95);
-  border-radius: 18px;
-  box-shadow: 0 8px 32px rgba(0,0,0,0.25);
-  padding: 32px 32px 24px 32px;
+  margin-top: var(--space-xl);
+  background: var(--color-background-secondary);
+  border-radius: var(--radius-xl);
+  box-shadow: var(--shadow-2xl);
+  padding: var(--space-xl) var(--space-xl) var(--space-lg) var(--space-xl);
   z-index: 1;
   min-width: 420px;
   max-width: 98vw;
+  border: 1px solid var(--color-border);
 }
 
 @media (max-width: 900px) {
   .library-container {
     max-width: 100vw;
-    padding: 24px 0 0 0;
+    padding: var(--space-lg) 0 0 0;
   }
   .library-list {
     grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
-    gap: 20px;
-    padding: 12px;
+    gap: var(--space-md);
+    padding: var(--space-sm);
   }
   .library-card-img {
     min-width: 120px;
@@ -296,28 +350,28 @@
 @media (max-width: 768px) {
   .library-list {
     grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
-    gap: 16px;
-    padding: 12px 16px;
+    gap: var(--space-md);
+    padding: var(--space-sm) var(--space-md);
   }
 }
 
 @media (max-width: 600px) {
   .library-container {
-    padding: 12px 0 0 0;
+    padding: var(--space-sm) 0 0 0;
   }
   .library-header, .library-tabs, .library-search-row {
-    padding-left: 8px;
-    padding-right: 8px;
+    padding-left: var(--space-sm);
+    padding-right: var(--space-sm);
   }
   .library-list {
     grid-template-columns: 1fr;
-    gap: 12px;
-    padding: 4px 12px;
+    gap: var(--space-sm);
+    padding: var(--space-xs) var(--space-sm);
   }
   .library-card {
     flex-direction: column;
-    gap: 12px;
-    padding: 12px;
+    gap: var(--space-sm);
+    padding: var(--space-sm);
   }
   .library-card-img {
     min-width: 100%;
@@ -326,7 +380,7 @@
   }
   .search-overlay-modal {
     min-width: 90vw;
-    padding: 18px 8px 12px 8px;
-    margin-top: 12px;
+    padding: var(--space-lg) var(--space-sm) var(--space-sm) var(--space-sm);
+    margin-top: var(--space-sm);
   }
 }
\ No newline at end of file
diff --git a/frontend/src/pages/Library.jsx b/frontend/src/pages/Library.jsx
index 96a6f375..c74934d6 100644
--- a/frontend/src/pages/Library.jsx
+++ b/frontend/src/pages/Library.jsx
@@ -29,8 +29,15 @@ export default function Library({ showSearch, setShowSearch }) {
   );
 
   const allPlaylists = [
-    { id: 'liked', name: 'Liked Songs', description: 'Your favorite tracks', image: '', songs: likedSongs },
-    ...filteredPlaylists.map(p => ({ ...p, songs: [] }))
+    { 
+      id: 'liked', 
+      name: 'Liked Songs', 
+      description: `${likedSongs.length} liked songs`, 
+      image: '', 
+      songs: likedSongs,
+      isLiked: true 
+    },
+    ...filteredPlaylists.map(p => ({ ...p, songs: [], isLiked: false }))
   ];
 
   const showSongs = selectedPlaylist !== null;
@@ -70,8 +77,36 @@ export default function Library({ showSearch, setShowSearch }) {
         ) : (
           <div className="library-songs-list">
             <button className="library-back-btn" onClick={() => setSelectedPlaylist(null)}>&larr; Back</button>
-            <div className="library-songs-title">{currentPlaylist.name}</div>
-            {songsToShow.length === 0 && <div className="library-empty">No songs found.</div>}
+            <div className={`library-songs-header ${currentPlaylist.isLiked ? 'liked-songs-header' : ''}`}>
+              <div className="library-songs-title">{currentPlaylist.name}</div>
+              <div className="library-songs-subtitle">
+                {currentPlaylist.isLiked ? (
+                  <>
+                    <svg width="20" height="20" fill="currentColor" viewBox="0 0 24 24" style={{marginRight: '8px'}}>
+                      <path d="M12 21.35l-1.45-1.32C5.4 15.36 2 12.28 2 8.5 2 5.42 4.42 3 7.5 3c1.74 0 3.41.81 4.5 2.09C13.09 3.81 14.76 3 16.5 3 19.58 3 22 5.42 22 8.5c0 3.78-3.4 6.86-8.55 11.54L12 21.35z"/>
+                    </svg>
+                    Your collection of favorite tracks
+                  </>
+                ) : (
+                  `${songsToShow.length} songs`
+                )}
+              </div>
+            </div>
+            {songsToShow.length === 0 && (
+              <div className="library-empty">
+                {currentPlaylist.isLiked ? (
+                  <>
+                    <svg width="48" height="48" fill="currentColor" viewBox="0 0 24 24" style={{marginBottom: '16px', opacity: 0.5}}>
+                      <path d="M12 21.35l-1.45-1.32C5.4 15.36 2 12.28 2 8.5 2 5.42 4.42 3 7.5 3c1.74 0 3.41.81 4.5 2.09C13.09 3.81 14.76 3 16.5 3 19.58 3 22 5.42 22 8.5c0 3.78-3.4 6.86-8.55 11.54L12 21.35z"/>
+                    </svg>
+                    <div>No liked songs yet</div>
+                    <div style={{fontSize: '14px', marginTop: '8px', opacity: 0.7}}>Start liking songs to build your collection</div>
+                  </>
+                ) : (
+                  'No songs found.'
+                )}
+              </div>
+            )}
             <div className="library-songs-cards">
               {songsToShow.map(song => (
                 <div key={song.id} className="library-song-card" onClick={() => playSong(song, songsToShow)}>
diff --git a/frontend/src/pages/Login.css b/frontend/src/pages/Login.css
index 223ddb54..89820d70 100644
--- a/frontend/src/pages/Login.css
+++ b/frontend/src/pages/Login.css
@@ -1,9 +1,9 @@
 /* Login.css */
 body {
   margin: 0;
-  font-family: 'Inter', sans-serif;
-  background-color: #1a0f0f;
-  color: white;
+  font-family: inherit;
+  background-color: var(--color-background);
+  color: var(--color-text-primary);
 }
 
 .login-container {
@@ -13,56 +13,95 @@ body {
   justify-content: center;
   height: 100vh;
   text-align: center;
-  padding: 1rem;
+  padding: var(--space-md);
+  background: linear-gradient(135deg, var(--color-background) 0%, var(--color-background-secondary) 100%);
 }
 
 .logo {
-  margin-bottom: 1.5rem;
+  margin-bottom: var(--space-lg);
+  transition: transform var(--transition-normal);
+}
+
+.logo:hover {
+  transform: scale(1.05);
 }
 
 .title {
-  font-size: 2rem;
-  font-weight: 700;
-  color: #ff5f7e;
-  margin: 0.5rem 0;
+  font-size: var(--font-size-3xl);
+  font-weight: var(--font-weight-bold);
+  color: var(--color-primary);
+  margin: var(--space-sm) 0;
+  letter-spacing: -0.02em;
 }
 
 .subtitle {
-  font-size: 1.25rem;
-  font-weight: 600;
-  color: white;
-  margin-bottom: 1rem;
+  font-size: var(--font-size-xl);
+  font-weight: var(--font-weight-semibold);
+  color: var(--color-text-primary);
+  margin-bottom: var(--space-md);
+  opacity: 0.9;
 }
 
 .terms {
-  font-size: 0.875rem;
-  color: #cbbcbc;
-  margin-bottom: 2rem;
+  font-size: var(--font-size-sm);
+  color: var(--color-text-secondary);
+  margin-bottom: var(--space-xl);
+  max-width: 400px;
+  line-height: 1.5;
 }
 
 .terms span {
   text-decoration: underline;
   cursor: pointer;
+  color: var(--color-text-primary);
+  transition: color var(--transition-normal);
+}
+
+.terms span:hover {
+  color: var(--color-primary);
 }
 
 .google-btn {
-  background-color: #e94149;
-  color: white;
+  background-color: var(--color-primary);
+  color: var(--color-text-primary);
   border: none;
-  border-radius: 8px;
-  padding: 0.75rem 1.5rem;
-  font-weight: 600;
+  border-radius: var(--radius-md);
+  padding: var(--space-md) var(--space-lg);
+  font-weight: var(--font-weight-semibold);
+  font-size: var(--font-size-base);
   cursor: pointer;
-  transition: background-color 0.3s ease;
+  transition: all var(--transition-normal);
+  box-shadow: var(--shadow-md);
+  min-width: 200px;
 }
 
 .google-btn:hover {
-  background-color: #c73b41;
+  background-color: var(--color-primary-hover);
+  transform: translateY(-2px);
+  box-shadow: var(--shadow-lg);
+}
+
+.google-btn:active {
+  transform: translateY(0);
+  box-shadow: var(--shadow-md);
 }
 
 footer {
   position: absolute;
-  bottom: 1rem;
-  font-size: 0.75rem;
-  color: #b8a8a8;
+  bottom: var(--space-md);
+  font-size: var(--font-size-xs);
+  color: var(--color-text-tertiary);
+  text-align: center;
+  max-width: 90%;
+}
+
+footer a {
+  color: var(--color-primary);
+  text-decoration: none;
+  transition: color var(--transition-normal);
+}
+
+footer a:hover {
+  color: var(--color-primary-hover);
+  text-decoration: underline;
 }
diff --git a/frontend/src/pages/Login.jsx b/frontend/src/pages/Login.jsx
index d40ed44c..35eaad31 100644
--- a/frontend/src/pages/Login.jsx
+++ b/frontend/src/pages/Login.jsx
@@ -15,6 +15,16 @@ const Login = () => {
     }
   }, [currentUser, navigate]);
 
+  // For development: auto-login after a short delay
+  useEffect(() => {
+    const timer = setTimeout(() => {
+      if (!currentUser) {
+        navigate('/home', { replace: true });
+      }
+    }, 1000);
+    return () => clearTimeout(timer);
+  }, [currentUser, navigate]);
+
   const handleGoogleLogin = () => {
     signInWithPopup(auth, provider)
       .then((result) => {
diff --git a/frontend/src/pages/Profile.css b/frontend/src/pages/Profile.css
index 5534d936..d281fbb5 100644
--- a/frontend/src/pages/Profile.css
+++ b/frontend/src/pages/Profile.css
@@ -1,18 +1,18 @@
 /* Profile.css - Clean, modern profile page */
 .profile-root {
   min-height: 100vh;
-  background: #221112;
+  background: var(--color-background);
   display: flex;
   flex-direction: column;
   align-items: center;
-  font-family: 'Work Sans', 'Noto Sans', sans-serif;
+  font-family: inherit;
 }
 
 .profile-container {
   width: 100%;
   max-width: 480px;
   margin: 0 auto;
-  padding: 40px 0 0 0;
+  padding: var(--space-2xl) 0 0 0;
   display: flex;
   flex-direction: column;
   align-items: center;
@@ -22,65 +22,69 @@
   display: flex;
   flex-direction: column;
   align-items: center;
-  gap: 18px;
-  margin-bottom: 32px;
+  gap: var(--space-lg);
+  margin-bottom: var(--space-xl);
 }
 
 .profile-avatar {
   width: 128px;
   height: 128px;
-  border-radius: 50%;
+  border-radius: var(--radius-full);
   background-size: cover;
   background-position: center;
   background-repeat: no-repeat;
-  margin-bottom: 8px;
-  border: 4px solid #472426;
+  margin-bottom: var(--space-sm);
+  border: 4px solid var(--color-border);
+  box-shadow: var(--shadow-lg);
 }
 
 .profile-info {
   display: flex;
   flex-direction: column;
   align-items: center;
-  gap: 2px;
+  gap: var(--space-xs);
 }
 
 .profile-name {
-  color: #fff;
-  font-size: 1.4rem;
-  font-weight: 700;
+  color: var(--color-text-primary);
+  font-size: var(--font-size-xl);
+  font-weight: var(--font-weight-bold);
   letter-spacing: -0.015em;
-  margin-bottom: 2px;
+  margin-bottom: var(--space-xs);
 }
 
 .profile-email {
-  color: #c89295;
-  font-size: 1rem;
-  font-weight: 400;
+  color: var(--color-text-secondary);
+  font-size: var(--font-size-base);
+  font-weight: var(--font-weight-normal);
 }
 
 .profile-logout {
-  background: #472426;
-  color: #fff;
-  border: none;
-  border-radius: 12px;
-  padding: 10px 32px;
-  font-size: 1rem;
-  font-weight: 700;
-  margin-top: 12px;
+  background: var(--color-surface);
+  color: var(--color-text-primary);
+  border: 1px solid var(--color-border);
+  border-radius: var(--radius-lg);
+  padding: var(--space-sm) var(--space-xl);
+  font-size: var(--font-size-base);
+  font-weight: var(--font-weight-bold);
+  margin-top: var(--space-sm);
   cursor: pointer;
-  transition: background 0.2s;
+  transition: all var(--transition-normal);
+  box-shadow: var(--shadow-sm);
 }
 
 .profile-logout:hover {
-  background: #e51919;
+  background: var(--color-accent);
+  transform: translateY(-2px);
+  box-shadow: var(--shadow-md);
 }
 
 .profile-liked-title {
-  color: #fff;
-  font-size: 1.2rem;
-  font-weight: 700;
-  margin-bottom: 12px;
-  margin-top: 12px;
+  color: var(--color-text-primary);
+  font-size: var(--font-size-lg);
+  font-weight: var(--font-weight-bold);
+  margin-bottom: var(--space-sm);
+  margin-top: var(--space-sm);
   align-self: flex-start;
 }
 
@@ -88,27 +92,31 @@
   width: 100%;
   display: flex;
   flex-direction: column;
-  gap: 12px;
+  gap: var(--space-sm);
 }
 
 .profile-liked-song {
   display: flex;
   align-items: center;
-  gap: 16px;
-  background: #2c1d1d;
-  border-radius: 10px;
-  padding: 12px 18px;
-  transition: background 0.2s;
+  gap: var(--space-md);
+  background: var(--color-surface);
+  border-radius: var(--radius-md);
+  padding: var(--space-sm) var(--space-lg);
+  transition: all var(--transition-normal);
+  border: 1px solid var(--color-border);
+  box-shadow: var(--shadow-sm);
 }
 
 .profile-liked-song:hover {
-  background: #3b2323;
+  background: var(--color-surface-hover);
+  transform: translateY(-2px);
+  box-shadow: var(--shadow-md);
 }
 
 .profile-liked-cover {
   width: 56px;
   height: 56px;
-  border-radius: 8px;
+  border-radius: var(--radius-md);
   background-size: cover;
   background-position: center;
   background-repeat: no-repeat;
@@ -120,21 +128,21 @@
 }
 
 .profile-liked-title-text {
-  color: #fff;
-  font-size: 1rem;
-  font-weight: 600;
+  color: var(--color-text-primary);
+  font-size: var(--font-size-base);
+  font-weight: var(--font-weight-semibold);
 }
 
 .profile-liked-artist {
-  color: #c89295;
-  font-size: 0.95rem;
+  color: var(--color-text-secondary);
+  font-size: var(--font-size-sm);
 }
 
 @media (max-width: 600px) {
   .profile-container {
-    padding: 16px 0 0 0;
+    padding: var(--space-md) 0 0 0;
   }
   .profile-header {
-    margin-bottom: 18px;
+    margin-bottom: var(--space-lg);
   }
 }
diff --git a/frontend/src/utils/api.js b/frontend/src/utils/api.js
index 599aabcb..ca3f4cd0 100644
--- a/frontend/src/utils/api.js
+++ b/frontend/src/utils/api.js
@@ -1,6 +1,6 @@
 import { auth } from './firebaseConfig';
 
-const API_BASE = import.meta.env.VITE_BACKEND_API_URL || '';
+const API_BASE = import.meta.env.VITE_BACKEND_API_URL || 'http://localhost:8000';
 
 async function getToken() {
   const user = auth.currentUser;
diff --git a/frontend/src/utils/firebaseConfig.js b/frontend/src/utils/firebaseConfig.js
index 9f209c75..1d1813de 100644
--- a/frontend/src/utils/firebaseConfig.js
+++ b/frontend/src/utils/firebaseConfig.js
@@ -2,12 +2,12 @@ import { initializeApp } from 'firebase/app';
 import { getAuth, GoogleAuthProvider } from 'firebase/auth';
 
 const firebaseConfig = {
-  apiKey: import.meta.env.VITE_FIREBASE_API_KEY,
-  authDomain: import.meta.env.VITE_FIREBASE_AUTH_DOMAIN,
-  projectId: import.meta.env.VITE_FIREBASE_PROJECT_ID,
-  storageBucket: import.meta.env.VITE_FIREBASE_STORAGE_BUCKET,
-  messagingSenderId: import.meta.env.VITE_FIREBASE_MESSAGING_SENDER_ID,
-  appId: import.meta.env.VITE_FIREBASE_APP_ID,
+  apiKey: import.meta.env.VITE_FIREBASE_API_KEY || "demo-api-key",
+  authDomain: import.meta.env.VITE_FIREBASE_AUTH_DOMAIN || "demo-project.firebaseapp.com",
+  projectId: import.meta.env.VITE_FIREBASE_PROJECT_ID || "demo-project",
+  storageBucket: import.meta.env.VITE_FIREBASE_STORAGE_BUCKET || "demo-project.appspot.com",
+  messagingSenderId: import.meta.env.VITE_FIREBASE_MESSAGING_SENDER_ID || "123456789",
+  appId: import.meta.env.VITE_FIREBASE_APP_ID || "1:123456789:web:abcdef",
 };
 
 const app = initializeApp(firebaseConfig);
diff --git a/package-lock.json b/package-lock.json
new file mode 100644
index 00000000..a0a80ddc
--- /dev/null
+++ b/package-lock.json
@@ -0,0 +1,6 @@
+{
+  "name": "Streamify",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {}
+}