:root {
  /* --- Primary palette (AI Studio blue) --- */
  --color-primary-50: #eff6ff;
  --color-primary-100: #dbeafe;
  --color-primary-300: #93c5fd;
  --color-primary-400: #60a5fa;
  --color-primary-500: #3b82f6;
  --color-primary-600: #2563eb;
  --color-primary-700: #1d4ed8;

  /* --- Accent (purple for brand gradient) --- */
  --color-accent-400: #a78bfa;
  --color-accent-500: #8b5cf6;
  --color-accent-600: #7c3aed;

  /* --- Brand gradient --- */
  --brand-gradient: linear-gradient(to bottom right, #3b82f6, #9333ea);

  /* --- Neutrals (slate-based, lighter) --- */
  --color-gray-0: #ffffff;
  --color-gray-50: #f8fafc;
  --color-gray-100: #f1f5f9;
  --color-gray-200: #e2e8f0;
  --color-gray-300: #cbd5e1;
  --color-gray-400: #94a3b8;
  --color-gray-500: #64748b;
  --color-gray-600: #475569;
  --color-gray-700: #334155;
  --color-gray-800: #1e293b;
  --color-gray-900: #0f172a;

  /* --- Semantic --- */
  --color-success: #34d399;
  --color-error: #f87171;
  --color-info: #60a5fa;

  /* --- Glass surfaces --- */
  --surface-page: #1f2b4e;
  --surface-page-light: #f8fafc;
  --surface-card: rgba(255, 255, 255, 0.6);
  --surface-elevated: var(--color-gray-0);
  --surface-overlay: rgba(15, 23, 42, 0.5);

  --surface-glass: rgba(255, 255, 255, 0.7);
  --surface-glass-strong: rgba(255, 255, 255, 0.82);
  --surface-glass-light: rgba(255, 255, 255, 0.92);
  --surface-glass-light-strong: rgba(255, 255, 255, 0.97);

  --glass-bg: rgba(255, 255, 255, 0.7);
  --glass-border: rgba(255, 255, 255, 0.4);
  --glass-card-bg: rgba(255, 255, 255, 0.6);
  --glass-card-border: rgba(255, 255, 255, 0.5);

  --border-glass: rgba(255, 255, 255, 0.4);
  --border-glass-light: rgba(255, 255, 255, 0.5);

  --glass-blur: blur(20px);
  --glass-blur-strong: blur(40px);
  --glass-blur-xl: blur(24px);

  --glass-panel-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.07);
  --glass-panel-inset: inset 0 0 0 1px rgba(255, 255, 255, 0.4);

  /* --- Text --- */
  --text-primary: var(--color-gray-900);
  --text-secondary: var(--color-gray-500);
  --text-tertiary: var(--color-gray-400);
  --text-inverse: var(--color-gray-0);
  --text-link: var(--color-primary-600);

  /* --- Spacing scale (4px base) --- */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;

  /* --- Typography --- */
  --font-sans: "Inter", ui-sans-serif, system-ui, -apple-system,
    BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-display: "Outfit", var(--font-sans);

  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  --leading-tight: 1.1;
  --leading-normal: 1.5;
  --leading-relaxed: 1.65;

  --font-medium: 500;
  --font-semibold: 600;
  --font-bold: 700;

  /* --- Border radius --- */
  --radius-sm: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-xl: 1.25rem;
  --radius-2xl: 1.5rem;
  --radius-3xl: 1.875rem;
  --radius-full: 9999px;

  /* --- Shadows (glass-friendly, softer and more spread) --- */
  --shadow-xs: 0 1px 3px rgba(14, 11, 30, 0.04);
  --shadow-md: 0 4px 16px rgba(14, 11, 30, 0.08);
  --shadow-lg: 0 8px 32px rgba(31, 38, 135, 0.07);
  --shadow-xl: 0 16px 48px rgba(14, 11, 30, 0.14);
  --shadow-glass-hover: 0 20px 40px rgba(31, 38, 135, 0.1);

  /* --- Transitions --- */
  --ease-default: cubic-bezier(0.4, 0, 0.2, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --duration-fast: 150ms;
  --duration-normal: 300ms;
  --duration-slow: 500ms;

  /* --- Layout --- */
  --container-xl: 1200px;
}