/* ============================================================================
   ZENIKIT — Design Tokens
   Physics-Informed UI Kit for Flask Applications
   
   Based on:
   - Untitled UI React variant system (common/sizes/colors)
   - IlangKural "Light within Light" philosophy (inner glow > outer shadow)
   - Kernel 8 damped oscillator animation parameters
   - VASVELVOGVEG expansion/collapse utility scoring
   ============================================================================ */

:root {
  /* ─── Color: Brand (Zeni Blue — derived from divine blue) ─── */
  --zk-brand-25: #F0F5FF;
  --zk-brand-50: #EFF6FF;
  --zk-brand-100: #DBEAFE;
  --zk-brand-200: #BFDBFE;
  --zk-brand-300: #93C5FD;
  --zk-brand-400: #60A5FA;
  --zk-brand-500: #3B82F6;
  --zk-brand-600: #2563EB;
  --zk-brand-700: #1D4ED8;
  --zk-brand-800: #1E40AF;
  --zk-brand-900: #1E3A5F;

  /* ─── Color: Accent (Divine Gold — warm radiance) ─── */
  --zk-gold-50: #FFFBEB;
  --zk-gold-100: #FEF3C7;
  --zk-gold-200: #FDE68A;
  --zk-gold-300: #FCD34D;
  --zk-gold-400: #FBBF24;
  --zk-gold-500: #F59E0B;
  --zk-gold-600: #D97706;
  --zk-gold-700: #B45309;

  /* ─── Color: Neutral (Slate) ─── */
  --zk-gray-25: #FCFCFD;
  --zk-gray-50: #F8FAFC;
  --zk-gray-100: #F1F5F9;
  --zk-gray-200: #E2E8F0;
  --zk-gray-300: #CBD5E1;
  --zk-gray-400: #94A3B8;
  --zk-gray-500: #64748B;
  --zk-gray-600: #475569;
  --zk-gray-700: #334155;
  --zk-gray-800: #1E293B;
  --zk-gray-900: #0F172A;
  --zk-gray-950: #020617;

  /* ─── Color: Semantic ─── */
  --zk-success-50: #F0FDF4;
  --zk-success-100: #DCFCE7;
  --zk-success-500: #22C55E;
  --zk-success-600: #16A34A;
  --zk-success-700: #15803D;

  --zk-warning-50: #FFFBEB;
  --zk-warning-100: #FEF3C7;
  --zk-warning-500: #F59E0B;
  --zk-warning-600: #D97706;
  --zk-warning-700: #B45309;

  --zk-error-50: #FEF2F2;
  --zk-error-100: #FEE2E2;
  --zk-error-500: #EF4444;
  --zk-error-600: #DC2626;
  --zk-error-700: #B91C1C;

  --zk-info-50: #EFF6FF;
  --zk-info-100: #DBEAFE;
  --zk-info-500: #3B82F6;
  --zk-info-600: #2563EB;
  --zk-info-700: #1D4ED8;

  /* ─── Color: Surfaces (IlangKural "inner light") ─── */
  --zk-bg-primary: #FFFFFF;
  --zk-bg-secondary: var(--zk-gray-50);
  --zk-bg-tertiary: var(--zk-gray-100);
  --zk-bg-overlay: rgba(15, 23, 42, 0.6);
  --zk-bg-glass: rgba(255, 255, 255, 0.72);
  --zk-bg-glass-dark: rgba(15, 23, 42, 0.72);

  /* ─── Color: Foreground (High Contrast Enforced) ─── */
  --zk-fg-primary: var(--zk-gray-900);
  --zk-fg-secondary: var(--zk-gray-700);
  /* Was 600 */
  --zk-fg-tertiary: var(--zk-gray-600);
  /* Was 500 */
  --zk-fg-quaternary: var(--zk-gray-500);
  /* Was 400 */
  --zk-fg-disabled: var(--zk-gray-400);
  /* Was 300 */
  --zk-fg-on-brand: #FFFFFF;
  --zk-fg-brand: var(--zk-brand-600);

  /* ─── Color: Borders ─── */
  --zk-border-primary: var(--zk-gray-200);
  --zk-border-secondary: var(--zk-gray-100);
  --zk-border-brand: var(--zk-brand-300);
  --zk-border-error: var(--zk-error-500);
  --zk-border-focus: var(--zk-brand-400);

  /* ─── Typography ─── */
  --zk-font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --zk-font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;

  /* Fluid type scale (mobile-first) - Dense Enterprise Standard */
  --zk-text-xs: 0.75rem;
  /* 12px - auxiliary */
  --zk-text-sm: 0.875rem;
  /* 14px - DEFAULT FOR UI (Buttons, Inputs, Cards) */
  --zk-text-md: 1rem;
  /* 16px - Base body text only */
  --zk-text-lg: 1.125rem;
  /* 18px */
  --zk-text-xl: 1.25rem;
  /* 20px */
  --zk-text-2xl: 1.5rem;
  /* 24px */
  --zk-text-3xl: 1.875rem;
  /* 30px */
  --zk-text-4xl: 2.25rem;
  /* 36px */
  --zk-text-5xl: 3rem;
  /* 48px */

  --zk-leading-tight: 1.25;
  --zk-leading-normal: 1.5;
  --zk-leading-relaxed: 1.75;

  --zk-weight-regular: 400;
  --zk-weight-medium: 500;
  --zk-weight-semibold: 600;
  --zk-weight-bold: 700;

  /* ─── Spacing (4px base unit) - Tighter arrays ─── */
  --zk-space-0: 0;
  --zk-space-0_5: 0.125rem;
  /* 2px */
  --zk-space-1: 0.25rem;
  /* 4px */
  --zk-space-1_5: 0.375rem;
  /* 6px */
  --zk-space-2: 0.5rem;
  /* 8px */
  --zk-space-2_5: 0.625rem;
  /* 10px */
  --zk-space-3: 0.75rem;
  /* 12px */
  --zk-space-3_5: 0.875rem;
  /* 14px */
  --zk-space-4: 1rem;
  /* 16px */
  --zk-space-5: 1.25rem;
  /* 20px */
  --zk-space-6: 1.5rem;
  /* 24px */
  --zk-space-8: 2rem;
  /* 32px */
  --zk-space-10: 2.5rem;
  /* 40px */
  --zk-space-12: 3rem;
  /* 48px */
  --zk-space-16: 4rem;
  /* 64px */
  --zk-space-20: 5rem;
  /* 80px */
  --zk-space-24: 6rem;
  /* 96px */

  /* ─── Border Radius ─── */
  --zk-radius-sm: 0.375rem;
  /* 6px */
  --zk-radius-md: 0.5rem;
  /* 8px */
  --zk-radius-lg: 0.75rem;
  /* 12px */
  --zk-radius-xl: 1rem;
  /* 16px */
  --zk-radius-2xl: 1.25rem;
  /* 20px */
  --zk-radius-full: 9999px;

  /* ─── Shadows (IlangKural: inner glow philosophy)
       Depth created by subtle inset glow + minimal outer shadow ─── */
  --zk-shadow-xs: 0 1px 2px 0 rgba(15, 23, 42, 0.05);
  --zk-shadow-sm: 0 1px 3px 0 rgba(15, 23, 42, 0.06),
    0 1px 2px -1px rgba(15, 23, 42, 0.06);
  --zk-shadow-md: 0 4px 6px -1px rgba(15, 23, 42, 0.07),
    0 2px 4px -2px rgba(15, 23, 42, 0.05);
  --zk-shadow-lg: 0 10px 15px -3px rgba(15, 23, 42, 0.08),
    0 4px 6px -4px rgba(15, 23, 42, 0.04);
  --zk-shadow-xl: 0 20px 25px -5px rgba(15, 23, 42, 0.08),
    0 8px 10px -6px rgba(15, 23, 42, 0.04);

  /* Inner glow for glassmorphism components (the "light within") */
  --zk-glow-sm: inset 0 1px 0 0 rgba(255, 255, 255, 0.08);
  --zk-glow-md: inset 0 1px 2px 0 rgba(255, 255, 255, 0.12);
  --zk-glow-brand: inset 0 1px 2px 0 rgba(124, 58, 237, 0.15);

  /* Skeumorphic shadow (from Untitled UI pattern) */
  --zk-shadow-skeumorphic: 0 1px 2px 0 rgba(15, 23, 42, 0.06),
    0 1px 3px 0 rgba(15, 23, 42, 0.1),
    inset 0 -1px 0 0 rgba(15, 23, 42, 0.04),
    inset 0 1px 0 0 rgba(255, 255, 255, 0.12);

  /* ─── Animation Physics (Kernel 8 Damped Oscillator)
       Ë + ζĖ + ω²(E - E_eq) = F_ext + B(u)
       
       ζ (zeta)  = damping ratio
       ω (omega) = natural frequency (rad/s)
       
       CSS spring approximations via cubic-bezier:
       - underdamped (ζ < 1): slight overshoot, feels alive
       - critically damped (ζ = 1): fastest without overshoot
       - overdamped (ζ > 1): slow, feels heavy ─── */

  /* Spring presets */
  --zk-spring-snappy: cubic-bezier(0.22, 1, 0.36, 1);
  /* ζ≈0.7, ω≈18 */
  --zk-spring-gentle: cubic-bezier(0.16, 1, 0.3, 1);
  /* ζ≈0.8, ω≈10 */
  --zk-spring-bouncy: cubic-bezier(0.34, 1.56, 0.64, 1);
  /* ζ≈0.4, ω≈14 */

  /* Duration presets (from ω: T ≈ 2π/ω) */
  --zk-duration-instant: 100ms;
  --zk-duration-fast: 150ms;
  --zk-duration-normal: 200ms;
  --zk-duration-slow: 300ms;
  --zk-duration-slower: 500ms;

  /* Transition shorthands */
  --zk-transition-fast: all 150ms var(--zk-spring-snappy);
  --zk-transition-normal: all 200ms var(--zk-spring-gentle);
  --zk-transition-slow: all 300ms var(--zk-spring-gentle);
  --zk-transition-transform: transform 200ms var(--zk-spring-snappy);

  /* ─── Z-Index Scale ─── */
  --zk-z-base: 0;
  --zk-z-dropdown: 100;
  --zk-z-sticky: 200;
  --zk-z-overlay: 300;
  --zk-z-modal: 400;
  --zk-z-toast: 500;
  --zk-z-dock: 600;
  --zk-z-tooltip: 700;

  /* ─── Breakpoints (for reference, used in media queries) ─── */
  --zk-bp-sm: 640px;
  --zk-bp-md: 768px;
  --zk-bp-lg: 1024px;
  --zk-bp-xl: 1280px;
  --zk-bp-2xl: 1440px;

  /* ─── Container ─── */
  --zk-container-sm: 640px;
  --zk-container-md: 768px;
  --zk-container-lg: 1024px;
  --zk-container-xl: 1280px;

  /* ─── Dock Specific ─── */
  --zk-dock-height: 4.5rem;
  /* 72px */
  --zk-dock-max-width: 28rem;
  /* 448px / max-w-md */
  --zk-dock-icon-size: 2.75rem;
  /* 44px — Apple HIG min tap target */
  --zk-dock-icon-gap: 0.5rem;
  --zk-dock-padding-x: 0.75rem;
  --zk-dock-padding-y: 0.5rem;
  --zk-dock-radius: var(--zk-radius-2xl);
  --zk-dock-blur: 12px;
  --zk-dock-safe-area: env(safe-area-inset-bottom, 0px);

  /* Dock magnification physics */
  --zk-dock-scale-hover: 1.15;
  /* Desktop hover scale */
  --zk-dock-scale-neighbor: 1.06;
  /* Adjacent icon scale on hover */
  --zk-dock-scale-active: 0.92;
  /* Tap press scale */
  --zk-dock-zeta: 0.6;
  /* Underdamped for slight bounce */
  --zk-dock-omega: 12;
  /* Snappy natural frequency */

  /* ─── Focus Ring ─── */
  --zk-focus-ring: 0 0 0 2px var(--zk-bg-primary), 0 0 0 4px var(--zk-brand-400);

  /* ─── Backdrop Blur (Glassmorphism) ─── */
  --zk-blur-sm: 4px;
  --zk-blur-md: 8px;
  --zk-blur-lg: 12px;
  --zk-blur-xl: 24px;
}

/* ─── Dark Mode ─── */
[data-theme="dark"] {
  --zk-bg-primary: var(--zk-gray-900);
  --zk-bg-secondary: var(--zk-gray-800);
  --zk-bg-tertiary: var(--zk-gray-700);
  --zk-bg-glass: rgba(15, 23, 42, 0.72);

  --zk-fg-primary: var(--zk-gray-50);
  --zk-fg-secondary: var(--zk-gray-300);
  --zk-fg-tertiary: var(--zk-gray-400);
  --zk-fg-quaternary: var(--zk-gray-500);
  --zk-fg-disabled: var(--zk-gray-600);
  --zk-fg-brand: var(--zk-brand-400);

  --zk-border-primary: var(--zk-gray-700);
  --zk-border-secondary: var(--zk-gray-800);
  --zk-border-focus: var(--zk-brand-500);

  --zk-shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.2);
  --zk-shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.25),
    0 1px 2px -1px rgba(0, 0, 0, 0.2);
  --zk-shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3),
    0 2px 4px -2px rgba(0, 0, 0, 0.2);

  --zk-glow-sm: inset 0 1px 0 0 rgba(255, 255, 255, 0.04);
  --zk-glow-md: inset 0 1px 2px 0 rgba(255, 255, 255, 0.06);
  --zk-glow-brand: inset 0 1px 2px 0 rgba(139, 92, 246, 0.2);

  --zk-shadow-skeumorphic: 0 1px 2px 0 rgba(0, 0, 0, 0.3),
    0 1px 3px 0 rgba(0, 0, 0, 0.4),
    inset 0 -1px 0 0 rgba(0, 0, 0, 0.2),
    inset 0 1px 0 0 rgba(255, 255, 255, 0.04);

  --zk-focus-ring: 0 0 0 2px var(--zk-gray-900), 0 0 0 4px var(--zk-brand-500);
}