/* ================================================
   ROOT LLC - CSS Variables
   世界最高峰のブランドデザインシステム
   ================================================ */

:root {
  /* ===== Color Palette ===== */
  /* Primary Colors */
  --root-black: #0a0a0a;
  --root-white: #ffffff;
  
  /* Gray Scale */
  --root-gray-50: #fafafa;
  --root-gray-100: #f5f5f5;
  --root-gray-200: #e5e5e5;
  --root-gray-300: #d4d4d4;
  --root-gray-400: #a3a3a3;
  --root-gray-600: #757575;
  --root-gray-800: #262626;
  --root-gray-900: #171717;
  
  /* Accent Colors */
  --root-accent: #2563eb;
  --root-accent-hover: #1d4ed8;
  
  /* ===== Typography ===== */
  /* Font Families */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-sans-jp: 'Noto Sans JP', 'Hiragino Sans', 'Hiragino Kaku Gothic ProN', 'Yu Gothic', sans-serif;
  
  /* Font Sizes */
  --text-xs: 0.75rem;      /* 12px */
  --text-sm: 0.875rem;     /* 14px */
  --text-base: 1rem;       /* 16px */
  --text-lg: 1.125rem;     /* 18px */
  --text-xl: 1.25rem;      /* 20px */
  --text-2xl: 1.5rem;      /* 24px */
  --text-3xl: 2rem;        /* 32px */
  --text-4xl: 2.5rem;      /* 40px */
  --text-5xl: 3.5rem;      /* 56px */
  --text-6xl: 4rem;        /* 64px */
  
  /* Line Heights */
  --leading-tight: 1.25;
  --leading-snug: 1.375;
  --leading-normal: 1.5;
  --leading-relaxed: 1.625;
  --leading-loose: 2;
  
  /* Font Weights */
  --font-light: 300;
  --font-normal: 400;
  --font-medium: 500;
  --font-semibold: 600;
  --font-bold: 700;
  
  /* Letter Spacing */
  --tracking-tighter: -0.02em;
  --tracking-tight: -0.01em;
  --tracking-normal: 0;
  --tracking-wide: 0.01em;
  --tracking-wider: 0.02em;
  
  /* ===== Spacing System (8px base) ===== */
  --space-1: 0.5rem;    /* 8px */
  --space-2: 1rem;      /* 16px */
  --space-3: 1.5rem;    /* 24px */
  --space-4: 2rem;      /* 32px */
  --space-5: 2.5rem;    /* 40px */
  --space-6: 3rem;      /* 48px */
  --space-8: 4rem;      /* 64px */
  --space-10: 5rem;     /* 80px */
  --space-12: 6rem;     /* 96px */
  --space-16: 8rem;     /* 128px */
  --space-20: 10rem;    /* 160px */
  --space-24: 12rem;    /* 192px */
  
  /* ===== Layout ===== */
  --max-width-content: 1200px;
  --max-width-wide: 1400px;
  --max-width-narrow: 800px;
  
  /* ===== Border Radius ===== */
  --radius-sm: 0.25rem;   /* 4px */
  --radius-md: 0.5rem;    /* 8px */
  --radius-lg: 1rem;      /* 16px */
  --radius-xl: 1.5rem;    /* 24px */
  
  /* ===== Shadows ===== */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
  
  /* Card Hover Shadow */
  --shadow-card-hover: 0 12px 24px rgba(0, 0, 0, 0.08);
  
  /* ===== Transitions ===== */
  --transition-base: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-fast: all 0.15s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  
  /* Easing Functions */
  --ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);
  --ease-out: cubic-bezier(0, 0, 0.2, 1);
  --ease-in: cubic-bezier(0.4, 0, 1, 1);
  
  /* ===== Z-Index Scale ===== */
  --z-base: 1;
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-fixed: 300;
  --z-modal-backdrop: 400;
  --z-modal: 500;
  --z-popover: 600;
  --z-tooltip: 700;
}

/* ===== Dark Mode Variables (Future) ===== */
@media (prefers-color-scheme: dark) {
  :root {
    /* Currently maintaining light theme only */
    /* Dark mode can be implemented in future phases */
  }
}