feat: overhaul design tokens — charcoal palette + amber accent

src/styles/main.css

@@ -1,57 +1,158 @@
 @import "tailwindcss";
 
 @theme {
-  --color-background: #0F0F0F;
-  --color-surface: #1A1A1A;
-  --color-surface-elevated: #242424;
-  --color-border: #2E2E2E;
-  --color-text-primary: #FFFFFF;
-  --color-text-secondary: #A0A0A0;
-  --color-amber: #F59E0B;
-  --color-amber-hover: #D97706;
-  --color-amber-light: #FCD34D;
-  --color-success: #22C55E;
-  --color-warning: #F59E0B;
-  --color-error: #EF4444;
-  --font-sans: 'IBM Plex Sans', system-ui, sans-serif;
+  /* Background layers */
+  --color-bg-base: #1A1A18;
+  --color-bg-surface: #222220;
+  --color-bg-elevated: #2C2C28;
+  --color-bg-inset: #141413;
+
+  /* Text hierarchy (warm whites) */
+  --color-text-primary: #F5F5F0;
+  --color-text-secondary: #8A8A82;
+  --color-text-tertiary: #5A5A54;
+
+  /* Borders */
+  --color-border-subtle: #2E2E2A;
+  --color-border-visible: #3D3D38;
+
+  /* Accent (amber) */
+  --color-accent: #D97706;
+  --color-accent-hover: #B45309;
+  --color-accent-muted: rgba(217, 119, 6, 0.12);
+  --color-accent-text: #FBBF24;
+
+  /* Status colors (semantic only) */
+  --color-status-running: #34D399;
+  --color-status-warning: #EAB308;
+  --color-status-error: #EF4444;
+  --color-status-info: #3B82F6;
+
+  /* Fonts */
+  --font-sans: 'Inter', system-ui, sans-serif;
   --font-mono: 'IBM Plex Mono', monospace;
 }
 
-* {
+@layer base {
+  * {
     margin: 0;
     padding: 0;
     box-sizing: border-box;
-}
+  }
 
-html, body, #app {
+  html, body, #app {
     height: 100%;
     width: 100%;
     overflow: hidden;
-}
+  }
 
-body {
+  body {
     font-family: var(--font-sans);
-  background-color: var(--color-background);
+    font-size: 0.8125rem;
+    line-height: 1.5;
+    background-color: var(--color-bg-base);
     color: var(--color-text-primary);
     -webkit-font-smoothing: antialiased;
     -moz-osx-font-smoothing: grayscale;
+  }
+
+  input:focus, select:focus, textarea:focus {
+    border-color: var(--color-accent) !important;
+    outline: none;
+    box-shadow: 0 0 0 2px var(--color-accent-muted);
+  }
 }
 
-/* Custom scrollbar styles */
+/* Scrollbar */
 ::-webkit-scrollbar {
-  width: 8px;
-  height: 8px;
+  width: 6px;
+  height: 6px;
 }
 
 ::-webkit-scrollbar-track {
-  background: var(--color-surface);
+  background: transparent;
 }
 
 ::-webkit-scrollbar-thumb {
-  background: var(--color-border);
-  border-radius: 4px;
+  background: var(--color-border-subtle);
+  border-radius: 3px;
 }
 
 ::-webkit-scrollbar-thumb:hover {
-  background: var(--color-text-secondary);
+  background: var(--color-text-tertiary);
+}
+
+/* Pulse animation for running timer dot */
+@keyframes pulse-dot {
+  0%, 100% { opacity: 0.6; }
+  50% { opacity: 1; }
+}
+
+.animate-pulse-dot {
+  animation: pulse-dot 2s ease-in-out infinite;
+}
+
+/* Pulse animation for timer seconds */
+@keyframes pulse-seconds {
+  0%, 100% { opacity: 0.85; }
+  50% { opacity: 1; }
+}
+
+.animate-pulse-seconds {
+  animation: pulse-seconds 1s ease-in-out infinite;
+}
+
+/* Modal animations */
+@keyframes modal-enter {
+  from {
+    opacity: 0;
+    transform: translateY(-8px);
+  }
+  to {
+    opacity: 1;
+    transform: translateY(0);
+  }
+}
+
+.animate-modal-enter {
+  animation: modal-enter 200ms ease-out;
+}
+
+/* Toast animations */
+@keyframes toast-enter {
+  from {
+    opacity: 0;
+    transform: translateY(-20px);
+  }
+  to {
+    opacity: 1;
+    transform: translateY(0);
+  }
+}
+
+.animate-toast-enter {
+  animation: toast-enter 200ms ease-out;
+}
+
+@keyframes toast-exit {
+  from {
+    opacity: 1;
+  }
+  to {
+    opacity: 0;
+  }
+}
+
+.animate-toast-exit {
+  animation: toast-exit 150ms ease-in forwards;
+}
+
+/* Pulse animation for timer colon */
+@keyframes pulse-colon {
+  0%, 100% { opacity: 0.4; }
+  50% { opacity: 1; }
+}
+
+.animate-pulse-colon {
+  animation: pulse-colon 1s ease-in-out infinite;
 }