/**
 * Nati News Theme - Design System Variables
 * Version: 2.0.0
 * 
 * Modern CSS custom properties (variables) for consistent design.
 * This file establishes a complete design token system.
 * 
 * Usage: var(--variable-name)
 * Example: background-color: var(--clr-brand-blue);
 */

:root {
    /* ========================================
     COLORS - Brand & Semantic
     ======================================== */

    /* Brand Colors */
    --clr-brand-blue: #0066cc;
    --clr-brand-blue-dark: #0052a3;
    --clr-brand-green: #5aad1e;

    /* Neutral Scale - Grayscale with consistent steps */
    --clr-white: #ffffff;
    --clr-neutral-50: #fafafa;
    --clr-neutral-100: #f5f5f5;
    --clr-neutral-200: #ebebeb;
    --clr-neutral-300: #d9d9d9;
    --clr-neutral-400: #9ca3af;
    --clr-neutral-500: #565661;
    --clr-neutral-600: #444444;
    --clr-neutral-700: #2d2c2c;
    --clr-neutral-800: #1a1a1a;
    --clr-neutral-900: #060e27;
    --clr-black: #000000;

    /* Semantic Color Assignments - Use these in components */
    --clr-text-primary: var(--clr-neutral-900);
    --clr-text-secondary: var(--clr-neutral-600);
    --clr-text-muted: var(--clr-neutral-400);
    --clr-text-inverse: var(--clr-white);

    --clr-link: var(--clr-brand-blue);
    --clr-link-hover: var(--clr-brand-blue-dark);

    --clr-bg-primary: var(--clr-white);
    --clr-bg-secondary: var(--clr-neutral-50);
    --clr-bg-tertiary: var(--clr-neutral-100);
    --clr-bg-overlay: rgba(0, 0, 0, 0.5);

    --clr-border-light: var(--clr-neutral-200);
    --clr-border-medium: var(--clr-neutral-300);
    --clr-border-dark: var(--clr-neutral-400);

    /* State Colors */
    --clr-success: #10b981;
    --clr-warning: #f59e0b;
    --clr-error: #ef4444;
    --clr-info: var(--clr-brand-blue);

    /* ========================================
     SPACING SCALE
     Base: 4px (0.25rem)
     ======================================== */

    --space-3xs: 0.25rem;
    /* 4px */
    --space-2xs: 0.5rem;
    /* 8px */
    --space-xs: 0.75rem;
    /* 12px */
    --space-sm: 1rem;
    /* 16px */
    --space-md: 1.5rem;
    /* 24px */
    --space-lg: 2rem;
    /* 32px */
    --space-xl: 3rem;
    /* 48px */
    --space-2xl: 4rem;
    /* 64px */
    --space-3xl: 6rem;
    /* 96px */
    --space-4xl: 8rem;
    /* 128px */

    /* ========================================
     TYPOGRAPHY
     ======================================== */

    /* Font Families */
    --font-family-base: 'Source Sans Pro', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-family-heading: var(--font-family-base);
    --font-family-mono: 'Courier New', Courier, monospace;

    /* Font Sizes - Fluid with clamp() */
    --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
    /* 12-14px */
    --text-sm: clamp(0.875rem, 0.8rem + 0.375vw, 1rem);
    /* 14-16px */
    --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
    /* 16-18px */
    --text-lg: clamp(1.125rem, 1rem + 0.625vw, 1.25rem);
    /* 18-20px */
    --text-xl: clamp(1.25rem, 1.1rem + 0.75vw, 1.5rem);
    /* 20-24px */
    --text-2xl: clamp(1.5rem, 1.3rem + 1vw, 2rem);
    /* 24-32px */
    --text-3xl: clamp(1.875rem, 1.6rem + 1.375vw, 2.5rem);
    /* 30-40px */
    --text-4xl: clamp(2.25rem, 1.9rem + 1.75vw, 3rem);
    /* 36-48px */
    --text-5xl: clamp(3rem, 2.5rem + 2.5vw, 4rem);
    /* 48-64px */

    /* Font Weights */
    --font-weight-light: 300;
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    --font-weight-black: 900;

    /* Line Heights */
    --leading-tight: 1.2;
    --leading-snug: 1.375;
    --leading-normal: 1.5;
    --leading-relaxed: 1.625;
    --leading-loose: 2;

    /* Letter Spacing */
    --tracking-tight: -0.025em;
    --tracking-normal: 0;
    --tracking-wide: 0.025em;
    --tracking-wider: 0.05em;

    /* ========================================
     SHADOWS - Elevation System
     ======================================== */

    --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.12);
    --shadow-lg: 0 6px 20px rgba(0, 0, 0, 0.15);
    --shadow-xl: 0 10px 30px rgba(0, 0, 0, 0.20);
    --shadow-2xl: 0 20px 50px rgba(0, 0, 0, 0.25);

    /* Focus Shadow */
    --shadow-focus: 0 0 0 3px rgba(0, 102, 204, 0.3);

    /* ========================================
     BORDER RADIUS
     ======================================== */

    --radius-none: 0;
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-2xl: 32px;
    --radius-full: 9999px;

    /* ========================================
     BORDERS
     ======================================== */

    --border-width-thin: 1px;
    --border-width-medium: 2px;
    --border-width-thick: 3px;

    --border-light: var(--border-width-thin) solid var(--clr-border-light);
    --border-medium: var(--border-width-thin) solid var(--clr-border-medium);
    --border-dark: var(--border-width-thin) solid var(--clr-border-dark);

    /* ========================================
     TRANSITIONS & ANIMATIONS
     ======================================== */

    /* Duration */
    --duration-instant: 100ms;
    --duration-fast: 150ms;
    --duration-base: 250ms;
    --duration-slow: 350ms;
    --duration-slower: 500ms;

    /* Easing Functions */
    --ease-in: cubic-bezier(0.4, 0, 1, 1);
    --ease-out: cubic-bezier(0, 0, 0.2, 1);
    --ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);
    --ease-bounce: cubic-bezier(0.68, -0.55, 0.265, 1.55);

    /* Combined Transitions */
    --transition-fast: var(--duration-fast) var(--ease-out);
    --transition-base: var(--duration-base) var(--ease-in-out);
    --transition-slow: var(--duration-slow) var(--ease-in-out);

    /* Common Transition Properties */
    --transition-colors: color var(--transition-base),
        background-color var(--transition-base),
        border-color var(--transition-base);
    --transition-transform: transform var(--transition-base);
    --transition-shadow: box-shadow var(--transition-base);
    --transition-opacity: opacity var(--transition-base);

    /* ========================================
     BREAKPOINTS
     (For reference - use in media queries)
     ======================================== */

    --breakpoint-sm: 640px;
    /* Small devices (large phones) */
    --breakpoint-md: 768px;
    /* Tablets */
    --breakpoint-lg: 1024px;
    /* Desktop */
    --breakpoint-xl: 1280px;
    /* Large desktop */
    --breakpoint-2xl: 1536px;
    /* Extra large desktop */

    /* ========================================
     Z-INDEX SCALE
     ======================================== */

    --z-base: 0;
    --z-dropdown: 10;
    --z-sticky: 20;
    --z-fixed: 30;
    --z-modal-backdrop: 40;
    --z-modal: 50;
    --z-popover: 60;
    --z-tooltip: 70;
    --z-notification: 80;

    /* ========================================
     LAYOUT
     ======================================== */

    /* Container Widths */
    --container-sm: 640px;
    --container-md: 768px;
    --container-lg: 1024px;
    --container-xl: 1280px;
    --container-2xl: 1536px;

    /* Content Width (readable line length) */
    --content-width: 65ch;

    /* ========================================
     COMPONENT-SPECIFIC TOKENS
     ======================================== */

    /* Buttons */
    --btn-padding-x: var(--space-md);
    --btn-padding-y: var(--space-xs);
    --btn-radius: var(--radius-md);
    --btn-font-weight: var(--font-weight-semibold);

    /* Cards */
    --card-padding: var(--space-lg);
    --card-radius: var(--radius-lg);
    --card-shadow: var(--shadow-sm);
    --card-shadow-hover: var(--shadow-md);

    /* Inputs */
    --input-padding-x: var(--space-sm);
    --input-padding-y: var(--space-xs);
    --input-radius: var(--radius-md);
    --input-border: var(--border-medium);
    --input-focus-ring: var(--shadow-focus);

    /* Header */
    --header-height: 80px;
    --header-height-mobile: 64px;

    /* Footer */
    --footer-padding: var(--space-3xl);

    /* ========================================
     UTILITIES
     ======================================== */

    /* Max widths for responsive images/media */
    --max-width-full: 100%;
    --max-width-screen: 100vw;

    /* Aspect Ratios */
    --aspect-square: 1 / 1;
    --aspect-video: 16 / 9;
    --aspect-wide: 21 / 9;
    --aspect-ultrawide: 32 / 9;
    --aspect-portrait: 3 / 4;
}

/* ========================================
   DARK MODE SUPPORT (Optional)
   Uncomment to enable dark mode
   ======================================== */

/*
@media (prefers-color-scheme: dark) {
  :root {
    --clr-text-primary: var(--clr-white);
    --clr-text-secondary: var(--clr-neutral-300);
    --clr-text-muted: var(--clr-neutral-400);
    --clr-text-inverse: var(--clr-neutral-900);
    
    --clr-bg-primary: var(--clr-neutral-900);
    --clr-bg-secondary: var(--clr-neutral-800);
    --clr-bg-tertiary: var(--clr-neutral-700);
    --clr-bg-overlay: rgba(255, 255, 255, 0.1);
    
    --clr-border-light: var(--clr-neutral-700);
    --clr-border-medium: var(--clr-neutral-600);
    --clr-border-dark: var(--clr-neutral-500);
  }
}
*/

/* ========================================
   ACCESSIBILITY - Respect User Preferences
   ======================================== */

/* Reduce motion for users who prefer it */
@media (prefers-reduced-motion: reduce) {

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* High contrast mode adjustments */
@media (prefers-contrast: high) {
    :root {
        --clr-border-light: var(--clr-neutral-800);
        --clr-border-medium: var(--clr-neutral-900);
    }
}