diff --git a/web/client/src/App.css b/web/client/src/App.css
new file mode 100644
index 0000000..f4673e4
--- /dev/null
+++ b/web/client/src/App.css
@@ -0,0 +1,369 @@
+/* ============================================
+   Minecraft-Themed Inventory Manager Dashboard
+   ============================================ */
+
+@import url('https://fonts.googleapis.com/css2?family=Silkscreen:wght@400;700&display=swap');
+
+:root {
+  --mc-dark: #1a1a1a;
+  --mc-darker: #0e0e0e;
+  --mc-stone: #7b7b7b;
+  --mc-stone-light: #9d9d9d;
+  --mc-stone-dark: #4b4b4b;
+  --mc-dirt: #6b5030;
+  --mc-dirt-dark: #4a3520;
+  --mc-oak: #8b6d3c;
+  --mc-oak-dark: #6b4e28;
+  --mc-oak-light: #b89b60;
+  --mc-grass: #5b8731;
+  --mc-grass-light: #80b94e;
+  --mc-grass-dark: #3d6b1a;
+  --mc-inv-bg: #c6c6c6;
+  --mc-inv-slot: #8b8b8b;
+  --mc-inv-slot-border: #373737;
+  --mc-inv-slot-light: #ffffff;
+  --mc-text-white: #e0e0e0;
+  --mc-text-gray: #a0a0a0;
+  --mc-text-dark: #404040;
+  --mc-text-yellow: #ffff55;
+  --mc-text-green: #55ff55;
+  --mc-text-red: #ff5555;
+  --mc-text-aqua: #55ffff;
+  --mc-text-gold: #ffaa00;
+  --mc-text-light-purple: #ff55ff;
+  --mc-text-blue: #5555ff;
+  --mc-diamond: #4aedd9;
+  --mc-emerald: #17dd62;
+  --mc-redstone: #ff0000;
+  --mc-lapis: #345ec3;
+  --mc-border-highlight: #ffffff55;
+  --mc-border-shadow: #00000088;
+}
+
+* {
+  margin: 0;
+  padding: 0;
+  box-sizing: border-box;
+}
+
+body {
+  font-family: 'Silkscreen', 'Courier New', monospace;
+  background: #2c2c2c;
+  color: var(--mc-text-white);
+  image-rendering: pixelated;
+  overflow: hidden;
+}
+
+.app {
+  width: 100vw;
+  height: 100vh;
+  display: flex;
+  flex-direction: column;
+  overflow: hidden;
+}
+
+/* === Header === */
+.app-header {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  padding: 0.75rem 1.25rem;
+  background: var(--mc-oak-dark);
+  border-bottom: 3px solid var(--mc-dark);
+  box-shadow:
+    inset 0 2px 0 var(--mc-oak-light),
+    inset 0 -2px 0 var(--mc-dirt-dark);
+  flex-shrink: 0;
+}
+
+.app-header h1 {
+  font-size: 1.1rem;
+  font-weight: 700;
+  color: var(--mc-text-yellow);
+  text-shadow: 2px 2px 0 var(--mc-dark);
+  letter-spacing: 0.05em;
+}
+
+/* === Connection Status === */
+.connection-status {
+  display: flex;
+  align-items: center;
+  gap: 0.5rem;
+  padding: 0.375rem 0.75rem;
+  border: 2px solid var(--mc-dark);
+  font-weight: 700;
+  font-size: 0.7rem;
+  text-shadow: 1px 1px 0 var(--mc-dark);
+}
+
+.connection-status.connected {
+  background: var(--mc-grass-dark);
+  color: var(--mc-text-green);
+  box-shadow: inset 0 1px 0 var(--mc-grass-light), inset 0 -1px 0 #2a5010;
+}
+
+.connection-status.disconnected {
+  background: #6b1a1a;
+  color: var(--mc-text-red);
+  box-shadow: inset 0 1px 0 #a03030, inset 0 -1px 0 #400e0e;
+}
+
+.status-dot {
+  width: 0.5rem;
+  height: 0.5rem;
+  border-radius: 0;
+  animation: mc-blink 1.5s steps(2) infinite;
+}
+
+.connected .status-dot {
+  background: var(--mc-text-green);
+  box-shadow: 0 0 4px var(--mc-text-green);
+}
+
+.disconnected .status-dot {
+  background: var(--mc-text-red);
+  box-shadow: 0 0 4px var(--mc-text-red);
+}
+
+@keyframes mc-blink {
+  0%, 100% { opacity: 1; }
+  50% { opacity: 0.3; }
+}
+
+/* === Command Toast === */
+.command-toast {
+  position: fixed;
+  top: 60px;
+  left: 50%;
+  transform: translateX(-50%);
+  padding: 0.5rem 1.5rem;
+  border: 2px solid var(--mc-dark);
+  font-size: 0.75rem;
+  font-weight: 700;
+  z-index: 1000;
+  text-shadow: 1px 1px 0 var(--mc-dark);
+  animation: toast-in 0.2s ease;
+}
+
+.command-toast.success {
+  background: var(--mc-grass-dark);
+  color: var(--mc-text-green);
+}
+
+.command-toast.error {
+  background: #6b1a1a;
+  color: var(--mc-text-red);
+}
+
+@keyframes toast-in {
+  from { opacity: 0; transform: translateX(-50%) translateY(-10px); }
+  to { opacity: 1; transform: translateX(-50%) translateY(0); }
+}
+
+/* === Main Content === */
+.app-content {
+  flex: 1;
+  display: flex;
+  overflow: hidden;
+}
+
+/* === Sidebar === */
+.sidebar {
+  width: 280px;
+  background: #333;
+  border-right: 3px solid var(--mc-dark);
+  overflow-y: auto;
+  flex-shrink: 0;
+}
+
+/* === Main Panel === */
+.main-panel {
+  flex: 1;
+  display: flex;
+  flex-direction: column;
+  overflow: hidden;
+}
+
+/* === Panel Tabs === */
+.panel-tabs {
+  display: flex;
+  gap: 0.25rem;
+  padding: 0.5rem;
+  background: #3b3b3b;
+  border-bottom: 3px solid var(--mc-dark);
+  overflow-x: auto;
+  flex-shrink: 0;
+}
+
+.panel-tabs button {
+  padding: 0.5rem 1rem;
+  border: 2px solid var(--mc-dark);
+  background: #5a5a5a;
+  color: var(--mc-text-gray);
+  border-radius: 0;
+  font-size: 0.875rem;
+  font-weight: 700;
+  cursor: pointer;
+  transition: all 0.1s;
+  white-space: nowrap;
+  font-family: 'Silkscreen', 'Courier New', monospace;
+  text-shadow: 1px 1px 0 var(--mc-dark);
+  box-shadow: inset 0 -2px 0 #444, inset 0 2px 0 #777;
+}
+
+.panel-tabs button:hover {
+  background: #6b6b6b;
+  color: var(--mc-text-white);
+}
+
+.panel-tabs button.active {
+  background: #4a8c2a;
+  color: white;
+  box-shadow: inset 0 2px 0 #6ab04c, inset 0 -2px 0 #2d6b1a;
+}
+
+.panel-content-wrapper {
+  flex: 1;
+  overflow: hidden;
+  display: flex;
+  flex-direction: column;
+}
+
+/* === Scrollbar === */
+::-webkit-scrollbar {
+  width: 8px;
+  height: 8px;
+}
+
+::-webkit-scrollbar-track {
+  background: #2c2c2c;
+}
+
+::-webkit-scrollbar-thumb {
+  background: #5a5a5a;
+  border: 1px solid var(--mc-dark);
+}
+
+::-webkit-scrollbar-thumb:hover {
+  background: #6b6b6b;
+}
+
+/* === Section styling === */
+.detail-section {
+  margin-bottom: 1rem;
+  padding: 0.875rem;
+  background: #3b3b3b;
+  border: 3px solid var(--mc-dark);
+  border-radius: 0;
+  box-shadow:
+    inset 0 2px 0 #555,
+    inset 0 -2px 0 #2a2a2a;
+}
+
+.detail-section h3 {
+  font-size: 0.8rem;
+  margin-bottom: 0.75rem;
+  color: var(--mc-text-gold);
+  font-weight: 700;
+  display: flex;
+  align-items: center;
+  gap: 0.5rem;
+  text-shadow: 1px 1px 0 var(--mc-dark);
+  text-transform: uppercase;
+  letter-spacing: 0.05em;
+}
+
+/* === MC Button === */
+.mc-btn {
+  padding: 0.5rem 0.75rem;
+  border: 2px solid var(--mc-dark);
+  border-radius: 0;
+  font-size: 0.7rem;
+  font-weight: 700;
+  cursor: pointer;
+  transition: all 0.05s;
+  color: white;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  gap: 0.25rem;
+  white-space: nowrap;
+  font-family: 'Silkscreen', 'Courier New', monospace;
+  text-shadow: 1px 1px 0 var(--mc-dark);
+  background: #6b6b6b;
+  box-shadow: inset 0 2px 0 #999, inset 0 -2px 0 #444;
+}
+
+.mc-btn:hover {
+  background: #7b7b7b;
+  box-shadow: inset 0 2px 0 #aaa, inset 0 -2px 0 #555;
+}
+
+.mc-btn:active {
+  background: #555;
+  box-shadow: inset 0 2px 0 #333, inset 0 -2px 0 #777;
+}
+
+.mc-btn.green {
+  background: var(--mc-grass-dark);
+  box-shadow: inset 0 2px 0 var(--mc-grass-light), inset 0 -2px 0 #2a5010;
+}
+.mc-btn.green:hover { background: var(--mc-grass); }
+
+.mc-btn.red {
+  background: #8b2e2e;
+  box-shadow: inset 0 2px 0 #bb4444, inset 0 -2px 0 #661a1a;
+}
+.mc-btn.red:hover { background: #a03e3e; }
+
+.mc-btn.blue {
+  background: #2e4a8b;
+  box-shadow: inset 0 2px 0 #4466bb, inset 0 -2px 0 #1a2a66;
+}
+.mc-btn.blue:hover { background: #3e5a9b; }
+
+.mc-btn.gold {
+  background: #8b6b2e;
+  box-shadow: inset 0 2px 0 #bb9944, inset 0 -2px 0 #664a1a;
+}
+.mc-btn.gold:hover { background: #9b7b3e; }
+
+/* === Responsive === */
+@media (max-width: 1024px) {
+  .sidebar {
+    width: 220px;
+  }
+}
+
+@media (max-width: 768px) {
+  .app-content {
+    flex-direction: column;
+  }
+
+  .sidebar {
+    width: 100%;
+    max-height: 200px;
+    border-right: none;
+    border-bottom: 3px solid var(--mc-dark);
+  }
+}
+
+@media (max-width: 480px) {
+  .app-header h1 {
+    font-size: 0.85rem;
+  }
+
+  .panel-tabs button {
+    font-size: 0.7rem;
+    padding: 0.4rem 0.6rem;
+  }
+}
+
+/* Reduced motion */
+@media (prefers-reduced-motion: reduce) {
+  * {
+    animation-duration: 0.01ms !important;
+    animation-iteration-count: 1 !important;
+    transition-duration: 0.01ms !important;
+  }
+}