/* ==========================================================================
   AIRH Design System — CSS Custom Properties
   Version: 1.0.0
   Base unit: 4px
   ========================================================================== */

:root {
  /* ---------------------------------------------------------------------------
     Spacing Scale (4px base)
     --------------------------------------------------------------------------- */
  --space-0: 0;
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-7: 28px;
  --space-8: 32px;
  --space-9: 36px;
  --space-10: 40px;
  --space-11: 44px;
  --space-12: 48px;
  --space-14: 56px;
  --space-16: 64px;
  --space-20: 80px;
  --space-24: 96px;

  /* ---------------------------------------------------------------------------
     Typography — Inter
     --------------------------------------------------------------------------- */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI',
    Roboto, Oxygen, Ubuntu, Cantarell, 'Helvetica Neue', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', Consolas,
    monospace;

  /* Font sizes */
  --text-xs: 11px;
  --text-sm: 13px;
  --text-base: 14px;
  --text-md: 15px;
  --text-lg: 16px;
  --text-xl: 18px;
  --text-2xl: 24px;
  --text-3xl: 30px;

  /* Line heights */
  --leading-none: 1;
  --leading-tight: 1.25;
  --leading-snug: 1.375;
  --leading-normal: 1.5;
  --leading-relaxed: 1.625;

  /* Font weights */
  --weight-regular: 400;
  --weight-medium: 500;
  --weight-semibold: 600;
  --weight-bold: 700;

  /* Letter spacing */
  --tracking-tight: -0.02em;
  --tracking-normal: 0;
  --tracking-wide: 0.02em;
  --tracking-wider: 0.04em;

  /* ---------------------------------------------------------------------------
     Border Radius (Neumorphic — generous)
     --------------------------------------------------------------------------- */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-xl: 18px;
  --radius-2xl: 24px;
  --radius-full: 9999px;

  /* ---------------------------------------------------------------------------
     Shadows
     --------------------------------------------------------------------------- */
  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07),
    0 2px 4px -1px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08),
    0 4px 6px -2px rgba(0, 0, 0, 0.04);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1),
    0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --shadow-panel: 0 0 0 1px rgba(0, 0, 0, 0.04),
    0 16px 48px -8px rgba(0, 0, 0, 0.12);
  --shadow-focus: 0 0 0 2px var(--color-accent), 0 0 0 4px rgba(35, 131, 226, 0.2);

  /* ---------------------------------------------------------------------------
     Transitions
     --------------------------------------------------------------------------- */
  --transition-fast: 120ms ease;
  --transition-base: 200ms ease;
  --transition-slow: 300ms ease;
  --transition-panel: 350ms cubic-bezier(0.16, 1, 0.3, 1);
  --transition-sheet: 400ms cubic-bezier(0.32, 0.72, 0, 1);
  --transition-spring: 500ms cubic-bezier(0.34, 1.56, 0.64, 1);
  --transition-opacity: opacity var(--transition-base);
  --transition-transform: transform var(--transition-panel);
  --transition-colors: color var(--transition-fast),
    background-color var(--transition-fast),
    border-color var(--transition-fast);

  /* ---------------------------------------------------------------------------
     Z-Index Scale
     --------------------------------------------------------------------------- */
  --z-base: 0;
  --z-above: 1;
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-sidebar: 300;
  --z-overlay: 400;
  --z-modal: 500;
  --z-panel: 550;
  --z-sheet: 600;
  --z-toast: 700;
  --z-tooltip: 800;

  /* ---------------------------------------------------------------------------
     Layout
     --------------------------------------------------------------------------- */
  --sidebar-width: 260px;
  --sidebar-collapsed: 64px;
  --topbar-height: 56px;
  --bottom-nav-height: 64px;
  --panel-width: 80%;
  --content-max-width: 1200px;
  --form-max-width: 640px;

  /* ---------------------------------------------------------------------------
     Breakpoints (for reference — use in @media)
     --------------------------------------------------------------------------- */
  /* --bp-sm: 640px;   */
  /* --bp-md: 768px;   */
  /* --bp-lg: 1024px;  */
  /* --bp-xl: 1280px;  */
  /* --bp-2xl: 1536px; */
}