/* Design System Variables & Theme Tokens */
:root {
  --primary: #4f46e5;
  --primary-hover: #4338ca;
  --primary-light: #eef2ff;
  --primary-glow: rgba(79, 70, 229, 0.2);

  --success: #10b981;
  --danger: #ef4444;
  --warning: #f59e0b;
  --info: #06b6d4;

  --bg-app: #f4f6fb;
  --bg-card: #ffffff;
  --bg-sidebar: #ffffff;
  --bg-chat: #f8fafc;
  --bg-input: #ffffff;
  --bg-hover: #f1f5f9;
  --bg-active: #e2e8f0;
  --bg-modal: rgba(15, 23, 42, 0.55);

  --text-main: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --text-inverse: #ffffff;

  --border-color: #e2e8f0;
  --border-light: #f1f5f9;

  --chat-bubble-me: #4f46e5;
  --chat-bubble-me-text: #ffffff;
  --chat-bubble-other: #ffffff;
  --chat-bubble-other-text: #0f172a;
  --chat-bubble-system: #e2e8f0;
  --chat-bubble-system-text: #64748b;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.05);

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;

  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
  --transition-smooth: 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Dark Mode Tokens */
[data-theme="dark"] {
  --bg-app: #0b0f19;
  --bg-card: #111827;
  --bg-sidebar: #131b2e;
  --bg-chat: #0f172a;
  --bg-input: #1e293b;
  --bg-hover: #1e293b;
  --bg-active: #334155;
  --bg-modal: rgba(0, 0, 0, 0.75);

  --text-main: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-muted: #64748b;

  --border-color: #1e293b;
  --border-light: #182234;

  --chat-bubble-me: #6366f1;
  --chat-bubble-me-text: #ffffff;
  --chat-bubble-other: #1e293b;
  --chat-bubble-other-text: #f1f5f9;
  --chat-bubble-system: #1e293b;
  --chat-bubble-system-text: #94a3b8;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.6);
}

/* Base Styles & Reset */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html, body {
  height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--text-main);
  background-color: var(--bg-app);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 9999px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}