/* CSS Custom Properties - Design System Tokens */
/* Production-ready design system variables for FitTrack Landing Page */

:root {
  /* ============================================
     BRAND COLORS - Primary Palette
     ============================================ */
  
  /* Primary Orange - Main brand color */
  --color-primary-50: hsl(14 100% 97%);
  --color-primary-100: hsl(14 100% 92%);
  --color-primary-200: hsl(14 100% 84%);
  --color-primary-300: hsl(14 100% 76%);
  --color-primary-400: hsl(14 100% 68%);
  --color-primary-500: hsl(14 100% 60%); /* #FF6B35 */
  --color-primary-600: hsl(14 100% 52%);
  --color-primary-700: hsl(14 100% 44%);
  --color-primary-800: hsl(14 100% 36%);
  --color-primary-900: hsl(14 100% 28%);
  --color-primary-950: hsl(14 100% 14%);
  
  /* Secondary Blue - Supporting brand color */
  --color-secondary-50: hsl(204 100% 97%);
  --color-secondary-100: hsl(204 100% 92%);
  --color-secondary-200: hsl(204 100% 84%);
  --color-secondary-300: hsl(204 100% 72%);
  --color-secondary-400: hsl(204 100% 60%);
  --color-secondary-500: hsl(204 100% 48%);
  --color-secondary-600: hsl(204 100% 40%);
  --color-secondary-700: hsl(204 100% 32%);
  --color-secondary-800: hsl(204 100% 27%); /* #004E89 */
  --color-secondary-900: hsl(204 100% 20%);
  --color-secondary-950: hsl(204 100% 10%);
  
  /* Accent Green - Success and energy color */
  --color-accent-50: hsl(164 100% 97%);
  --color-accent-100: hsl(164 100% 92%);
  --color-accent-200: hsl(164 100% 84%);
  --color-accent-300: hsl(164 100% 72%);
  --color-accent-400: hsl(164 100% 60%);
  --color-accent-500: hsl(164 100% 47%);
  --color-accent-600: hsl(164 100% 40%);
  --color-accent-700: hsl(164 100% 33%); /* #00A878 */
  --color-accent-800: hsl(164 100% 26%);
  --color-accent-900: hsl(164 100% 19%);
  --color-accent-950: hsl(164 100% 10%);
  
  /* ============================================
     NEUTRAL COLORS - Grays
     ============================================ */
  
  --color-neutral-0: hsl(0 0% 100%);
  --color-neutral-50: hsl(210 20% 98%);
  --color-neutral-100: hsl(210 20% 95%);
  --color-neutral-200: hsl(210 16% 90%);
  --color-neutral-300: hsl(210 14% 83%);
  --color-neutral-400: hsl(210 12% 71%);
  --color-neutral-500: hsl(210 10% 55%);
  --color-neutral-600: hsl(210 12% 43%);
  --color-neutral-700: hsl(210 14% 33%);
  --color-neutral-800: hsl(210 16% 23%);
  --color-neutral-900: hsl(210 18% 15%);
  --color-neutral-950: hsl(210 20% 8%);
  --color-neutral-1000: hsl(0 0% 0%);
  
  /* ============================================
     SEMANTIC COLORS
     ============================================ */
  
  /* Success */
  --color-success-light: var(--color-accent-300);
  --color-success: var(--color-accent-700);
  --color-success-dark: var(--color-accent-900);
  
  /* Warning */
  --color-warning-light: hsl(45 100% 85%);
  --color-warning: hsl(45 100% 51%);
  --color-warning-dark: hsl(45 100% 35%);
  
  /* Error */
  --color-error-light: hsl(0 84% 85%);
  --color-error: hsl(0 84% 60%);
  --color-error-dark: hsl(0 84% 40%);
  
  /* Info */
  --color-info-light: var(--color-secondary-300);
  --color-info: var(--color-secondary-600);
  --color-info-dark: var(--color-secondary-900);
  
  /* ============================================
     SURFACE COLORS - Light Mode
     ============================================ */
  
  --color-background: var(--color-neutral-0);
  --color-surface: var(--color-neutral-50);
  --color-surface-elevated: var(--color-neutral-0);
  --color-surface-overlay: var(--color-neutral-0);
  
  /* Text colors */
  --color-text-primary: var(--color-neutral-900);
  --color-text-secondary: var(--color-neutral-700);
  --color-text-tertiary: var(--color-neutral-500);
  --color-text-disabled: var(--color-neutral-400);
  --color-text-inverse: var(--color-neutral-0);
  
  /* Border colors */
  --color-border-light: var(--color-neutral-200);
  --color-border: var(--color-neutral-300);
  --color-border-strong: var(--color-neutral-400);
  
  /* ============================================
     TYPOGRAPHY SCALE
     ============================================ */
  
  /* Font families */
  --font-family-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
  --font-family-serif: Georgia, Cambria, "Times New Roman", Times, serif;
  --font-family-mono: ui-monospace, "Cascadia Code", "Source Code Pro", Menlo, Consolas, "DejaVu Sans Mono", monospace;
  --font-family-display: var(--font-family-sans);
  --font-family-body: var(--font-family-sans);
  
  /* Font sizes - Fluid typography with clamp() */
  --font-size-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --font-size-sm: clamp(0.875rem, 0.8rem + 0.375vw, 1rem);
  --font-size-base: clamp(1rem, 0.9rem + 0.5vw, 1.125rem);
  --font-size-md: clamp(1.125rem, 1rem + 0.625vw, 1.25rem);
  --font-size-lg: clamp(1.25rem, 1.1rem + 0.75vw, 1.5rem);
  --font-size-xl: clamp(1.5rem, 1.3rem + 1vw, 1.875rem);
  --font-size-2xl: clamp(1.875rem, 1.6rem + 1.375vw, 2.25rem);
  --font-size-3xl: clamp(2.25rem, 1.9rem + 1.75vw, 3rem);
  --font-size-4xl: clamp(3rem, 2.5rem + 2.5vw, 3.75rem);
  --font-size-5xl: clamp(3.75rem, 3rem + 3.75vw, 4.5rem);
  
  /* Line heights */
  --line-height-none: 1;
  --line-height-tight: 1.2;
  --line-height-snug: 1.375;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.625;
  --line-height-loose: 2;
  
  /* Font weights */
  --font-weight-thin: 100;
  --font-weight-extralight: 200;
  --font-weight-light: 300;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --font-weight-extrabold: 800;
  --font-weight-black: 900;
  
  /* Letter spacing */
  --letter-spacing-tighter: -0.05em;
  --letter-spacing-tight: -0.025em;
  --letter-spacing-normal: 0;
  --letter-spacing-wide: 0.025em;
  --letter-spacing-wider: 0.05em;
  --letter-spacing-widest: 0.1em;
  
  /* ============================================
     SPACING SCALE - 4px base unit
     ============================================ */
  
  --space-0: 0;
  --space-px: 1px;
  --space-0-5: 0.125rem; /* 2px */
  --space-1: 0.25rem; /* 4px */
  --space-1-5: 0.375rem; /* 6px */
  --space-2: 0.5rem; /* 8px */
  --space-2-5: 0.625rem; /* 10px */
  --space-3: 0.75rem; /* 12px */
  --space-3-5: 0.875rem; /* 14px */
  --space-4: 1rem; /* 16px */
  --space-5: 1.25rem; /* 20px */
  --space-6: 1.5rem; /* 24px */
  --space-7: 1.75rem; /* 28px */
  --space-8: 2rem; /* 32px */
  --space-9: 2.25rem; /* 36px */
  --space-10: 2.5rem; /* 40px */
  --space-11: 2.75rem; /* 44px */
  --space-12: 3rem; /* 48px */
  --space-14: 3.5rem; /* 56px */
  --space-16: 4rem; /* 64px */
  --space-20: 5rem; /* 80px */
  --space-24: 6rem; /* 96px */
  --space-28: 7rem; /* 112px */
  --space-32: 8rem; /* 128px */
  --space-36: 9rem; /* 144px */
  --space-40: 10rem; /* 160px */
  --space-44: 11rem; /* 176px */
  --space-48: 12rem; /* 192px */
  --space-52: 13rem; /* 208px */
  --space-56: 14rem; /* 224px */
  --space-60: 15rem; /* 240px */
  --space-64: 16rem; /* 256px */
  --space-72: 18rem; /* 288px */
  --space-80: 20rem; /* 320px */
  --space-96: 24rem; /* 384px */
  
  /* Fluid spacing using max() for responsive scaling */
  --space-fluid-xs: max(0.25rem, 1vw);
  --space-fluid-sm: max(0.5rem, 2vw);
  --space-fluid-md: max(1rem, 3vw);
  --space-fluid-lg: max(1.5rem, 4vw);
  --space-fluid-xl: max(2rem, 5vw);
  --space-fluid-2xl: max(3rem, 6vw);
  --space-fluid-3xl: max(4rem, 8vw);
  
  /* ============================================
     BORDER RADIUS
     ============================================ */
  
  --radius-none: 0;
  --radius-sm: 0.125rem; /* 2px */
  --radius-base: 0.25rem; /* 4px */
  --radius-md: 0.375rem; /* 6px */
  --radius-lg: 0.5rem; /* 8px */
  --radius-xl: 0.75rem; /* 12px */
  --radius-2xl: 1rem; /* 16px */
  --radius-3xl: 1.5rem; /* 24px */
  --radius-full: 9999px;
  
  /* ============================================
     SHADOWS
     ============================================ */
  
  --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px -1px rgba(0, 0, 0, 0.1);
  --shadow-base: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
  --shadow-2xl: 0 35px 60px -15px rgba(0, 0, 0, 0.3);
  --shadow-inner: inset 0 2px 4px 0 rgba(0, 0, 0, 0.05);
  --shadow-none: 0 0 #0000;
  
  /* Colored shadows for brand elements */
  --shadow-primary: 0 10px 25px -5px rgba(255, 107, 53, 0.3);
  --shadow-secondary: 0 10px 25px -5px rgba(0, 78, 137, 0.3);
  --shadow-accent: 0 10px 25px -5px rgba(0, 168, 120, 0.3);
  
  /* ============================================
     BREAKPOINTS - For reference in media queries
     ============================================ */
  
  --breakpoint-xs: 375px;
  --breakpoint-sm: 640px;
  --breakpoint-md: 768px;
  --breakpoint-lg: 1024px;
  --breakpoint-xl: 1280px;
  --breakpoint-2xl: 1536px;
  
  /* ============================================
     Z-INDEX SCALE
     ============================================ */
  
  --z-index-base: 0;
  --z-index-dropdown: 1000;
  --z-index-sticky: 1100;
  --z-index-fixed: 1200;
  --z-index-modal-backdrop: 1300;
  --z-index-modal: 1400;
  --z-index-popover: 1500;
  --z-index-tooltip: 1600;
  
  /* ============================================
     TRANSITIONS & ANIMATIONS
     ============================================ */
  
  --transition-duration-fast: 150ms;
  --transition-duration-base: 200ms;
  --transition-duration-slow: 300ms;
  --transition-duration-slower: 500ms;
  
  --transition-timing-ease: ease;
  --transition-timing-ease-in: ease-in;
  --transition-timing-ease-out: ease-out;
  --transition-timing-ease-in-out: ease-in-out;
  --transition-timing-linear: linear;
  
  /* Common transitions */
  --transition-all: all var(--transition-duration-base) var(--transition-timing-ease-in-out);
  --transition-colors: color var(--transition-duration-base) var(--transition-timing-ease-in-out),
                       background-color var(--transition-duration-base) var(--transition-timing-ease-in-out),
                       border-color var(--transition-duration-base) var(--transition-timing-ease-in-out);
  --transition-transform: transform var(--transition-duration-base) var(--transition-timing-ease-in-out);
  --transition-opacity: opacity var(--transition-duration-base) var(--transition-timing-ease-in-out);
  
  /* ============================================
     CONTAINER WIDTHS
     ============================================ */
  
  --container-xs: 20rem; /* 320px */
  --container-sm: 24rem; /* 384px */
  --container-md: 28rem; /* 448px */
  --container-lg: 32rem; /* 512px */
  --container-xl: 36rem; /* 576px */
  --container-2xl: 42rem; /* 672px */
  --container-3xl: 48rem; /* 768px */
  --container-4xl: 56rem; /* 896px */
  --container-5xl: 64rem; /* 1024px */
  --container-6xl: 72rem; /* 1152px */
  --container-7xl: 80rem; /* 1280px */
  --container-full: 100%;
  
  /* ============================================
     DYNAMIC VIEWPORT UNITS
     ============================================ */
  
  --vh: 1vh;
  --dvh: 1dvh;
  --svh: 1svh;
  --lvh: 1lvh;
}

/* ============================================
   DARK MODE - Automatic theme switching
   ============================================ */

@media (prefers-color-scheme: dark) {
  :root {
    /* Inverted surface colors for dark mode */
    --color-background: var(--color-neutral-950);
    --color-surface: var(--color-neutral-900);
    --color-surface-elevated: var(--color-neutral-800);
    --color-surface-overlay: var(--color-neutral-900);
    
    /* Adjusted text colors for dark mode */
    --color-text-primary: var(--color-neutral-50);
    --color-text-secondary: var(--color-neutral-300);
    --color-text-tertiary: var(--color-neutral-500);
    --color-text-disabled: var(--color-neutral-600);
    --color-text-inverse: var(--color-neutral-900);
    
    /* Adjusted border colors for dark mode */
    --color-border-light: var(--color-neutral-800);
    --color-border: var(--color-neutral-700);
    --color-border-strong: var(--color-neutral-600);
    
    /* Lighter brand colors for better contrast in dark mode */
    --color-primary-500: hsl(14 100% 65%);
    --color-secondary-500: hsl(204 100% 55%);
    --color-accent-500: hsl(164 100% 50%);
    
    /* Adjusted shadows for dark mode */
    --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.4), 0 1px 2px -1px rgba(0, 0, 0, 0.4);
    --shadow-base: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -2px rgba(0, 0, 0, 0.4);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -4px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.4), 0 8px 10px -6px rgba(0, 0, 0, 0.4);
    --shadow-xl: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    --shadow-2xl: 0 35px 60px -15px rgba(0, 0, 0, 0.6);
  }
}

/* ============================================
   HIGH CONTRAST MODE
   ============================================ */

@media (prefers-contrast: high) {
  :root {
    /* Increase contrast for better accessibility */
    --color-text-primary: var(--color-neutral-1000);
    --color-text-secondary: var(--color-neutral-800);
    --color-border: var(--color-neutral-500);
    --color-border-strong: var(--color-neutral-700);
  }
  
  @media (prefers-color-scheme: dark) {
    :root {
      --color-text-primary: var(--color-neutral-0);
      --color-text-secondary: var(--color-neutral-200);
      --color-border: var(--color-neutral-500);
      --color-border-strong: var(--color-neutral-300);
    }
  }
}