/* ==========================================================================
   Playnexi Design System - CSS Custom Properties
   Apple-clean + Duolingo-friendly
   ========================================================================== */

:root {
    /* --- Primary Colors --- */
    --color-primary: #4F46E5;
    --color-primary-light: #6366F1;
    --color-primary-dark: #4338CA;
    --color-primary-50: #EEF2FF;
    --color-primary-100: #E0E7FF;
    --color-primary-200: #C7D2FE;

    /* --- Secondary / Accent (Warm, playful) --- */
    --color-secondary: #F59E0B;
    --color-secondary-light: #FBBF24;
    --color-secondary-dark: #D97706;
    --color-secondary-50: #FFFBEB;
    --color-secondary-100: #FEF3C7;

    /* --- Success --- */
    --color-success: #10B981;
    --color-success-light: #34D399;
    --color-success-dark: #059669;
    --color-success-50: #ECFDF5;

    /* --- Warning --- */
    --color-warning: #F59E0B;
    --color-warning-light: #FBBF24;
    --color-warning-dark: #D97706;
    --color-warning-50: #FFFBEB;

    /* --- Danger / Error --- */
    --color-danger: #EF4444;
    --color-danger-light: #F87171;
    --color-danger-dark: #DC2626;
    --color-danger-50: #FEF2F2;

    /* --- Info --- */
    --color-info: #06B6D4;
    --color-info-light: #22D3EE;
    --color-info-dark: #0891B2;
    --color-info-50: #ECFEFF;

    /* --- Accent Colors (for categories, badges, charts) --- */
    --color-accent-purple: #8B5CF6;
    --color-accent-pink: #EC4899;
    --color-accent-teal: #14B8A6;
    --color-accent-orange: #F97316;
    --color-accent-lime: #84CC16;
    --color-accent-sky: #0EA5E9;

    /* --- Neutral / Text --- */
    --color-text-primary: #111827;
    --color-text-secondary: #6B7280;
    --color-text-tertiary: #9CA3AF;
    --color-text-disabled: #D1D5DB;
    --color-text-inverse: #FFFFFF;
    --color-text-link: var(--color-primary);

    /* --- Backgrounds --- */
    --color-bg-primary: #FFFFFF;
    --color-bg-secondary: #F9FAFB;
    --color-bg-tertiary: #F3F4F6;
    --color-bg-dark: #111827;
    --color-bg-overlay: rgba(0, 0, 0, 0.5);

    /* --- Borders --- */
    --color-border-light: #F3F4F6;
    --color-border-default: #E5E7EB;
    --color-border-dark: #D1D5DB;
    --color-border-focus: var(--color-primary);

    /* --- Shadows --- */
    --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08), 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07), 0 2px 4px rgba(0, 0, 0, 0.04);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.08), 0 4px 6px rgba(0, 0, 0, 0.04);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.08), 0 10px 10px rgba(0, 0, 0, 0.03);
    --shadow-inner: inset 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-focus: 0 0 0 3px rgba(79, 70, 229, 0.15);

    /* --- Border Radius --- */
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-2xl: 24px;
    --radius-full: 9999px;

    /* --- Spacing --- */
    --space-1: 0.25rem;   /* 4px */
    --space-2: 0.5rem;    /* 8px */
    --space-3: 0.75rem;   /* 12px */
    --space-4: 1rem;      /* 16px */
    --space-5: 1.25rem;   /* 20px */
    --space-6: 1.5rem;    /* 24px */
    --space-8: 2rem;      /* 32px */
    --space-10: 2.5rem;   /* 40px */
    --space-12: 3rem;     /* 48px */
    --space-16: 4rem;     /* 64px */
    --space-20: 5rem;     /* 80px */
    --space-24: 6rem;     /* 96px */

    /* --- Typography --- */
    --font-family-base: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-family-heading: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-family-mono: 'SF Mono', 'Fira Code', 'Consolas', monospace;

    --font-size-xs: 0.75rem;    /* 12px */
    --font-size-sm: 0.875rem;   /* 14px */
    --font-size-base: 1rem;     /* 16px */
    --font-size-lg: 1.125rem;   /* 18px */
    --font-size-xl: 1.25rem;    /* 20px */
    --font-size-2xl: 1.5rem;    /* 24px */
    --font-size-3xl: 1.875rem;  /* 30px */
    --font-size-4xl: 2.25rem;   /* 36px */
    --font-size-5xl: 3rem;      /* 48px */

    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    --font-weight-extrabold: 800;

    --line-height-tight: 1.25;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.75;

    /* --- Transitions --- */
    --transition-fast: 150ms ease;
    --transition-base: 200ms ease;
    --transition-slow: 300ms ease;

    /* --- Z-Index --- */
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-fixed: 300;
    --z-modal-backdrop: 400;
    --z-modal: 500;
    --z-tooltip: 600;
    --z-toast: 700;

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

    /* --- Sidebar --- */
    --sidebar-width: 260px;
    --sidebar-collapsed-width: 72px;
    --navbar-height: 64px;
    --bottom-nav-height: 64px;
}