/* ============================================
   Design Tokens - Donghe Materials Website
   ============================================ */

:root {
  /* ========== Brand Colors ========== */
  --primary: #E31B23;
  --primary-dark: #B81820;
  --primary-light: #FF4D54;
  --primary-alpha-10: rgba(227, 27, 35, 0.1);
  --primary-alpha-20: rgba(227, 27, 35, 0.2);

  /* ========== Neutral Colors ========== */
  --black: #000000;
  --gray-900: #1A1A1A;
  --gray-800: #2D2D2D;
  --gray-700: #3D3D3D;
  --gray-600: #4A4A4A;
  --gray-500: #666666;
  --gray-400: #808080;
  --gray-300: #D4D4D4;
  --gray-200: #E5E5E5;
  --gray-100: #F5F5F5;
  --gray-50: #FAFAFA;
  --white: #FFFFFF;

  /* ========== Semantic Colors ========== */
  --success: #22C55E;
  --success-light: rgba(34, 197, 94, 0.1);
  --warning: #F59E0B;
  --error: #EF4444;

  /* ========== Gradients ========== */
  --gradient-dark: linear-gradient(135deg, #1A1A1A 0%, #2D2D2D 100%);
  --gradient-darker: linear-gradient(180deg, #0A0A0A 0%, #1A1A1A 100%);
  --gradient-hero: linear-gradient(180deg, rgba(0,0,0,0.85) 0%, rgba(0,0,0,0.65) 40%, rgba(0,0,0,0.8) 100%);
  --gradient-cta: linear-gradient(135deg, #E31B23 0%, #B81820 100%);
  --gradient-cta-hover: linear-gradient(135deg, #FF4D54 0%, #E31B23 100%);
  --gradient-glass: linear-gradient(135deg, rgba(255,255,255,0.12) 0%, rgba(255,255,255,0.05) 100%);
  --gradient-text: linear-gradient(135deg, #FFFFFF 0%, #D4D4D4 100%);

  /* ========== Glassmorphism ========== */
  --glass-bg: rgba(255, 255, 255, 0.08);
  --glass-bg-light: rgba(255, 255, 255, 0.12);
  --glass-border: rgba(255, 255, 255, 0.15);
  --glass-border-light: rgba(255, 255, 255, 0.25);
  --glass-blur: blur(20px);
  --glass-blur-light: blur(10px);

  /* ========== Typography ========== */
  --font-primary: "Inter", "Noto Sans SC", "Microsoft YaHei", -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: "JetBrains Mono", "SF Mono", "Monaco", "Consolas", monospace;

  /* 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: 1.875rem;    /* 30px */
  --text-4xl: 2.25rem;     /* 36px */
  --text-5xl: 3rem;        /* 48px */
  --text-6xl: 3.75rem;     /* 60px */
  --text-7xl: 4.5rem;      /* 72px */

  /* Font Weights */
  --font-normal: 400;
  --font-medium: 500;
  --font-semibold: 600;
  --font-bold: 700;

  /* Line Heights */
  --leading-none: 1;
  --leading-tight: 1.25;
  --leading-snug: 1.375;
  --leading-normal: 1.5;
  --leading-relaxed: 1.625;
  --leading-loose: 2;

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

  /* ========== Spacing Scale ========== */
  --space-0: 0;
  --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-14: 3.5rem;      /* 56px */
  --space-16: 4rem;        /* 64px */
  --space-20: 5rem;        /* 80px */
  --space-24: 6rem;        /* 96px */
  --space-32: 8rem;        /* 128px */

  /* ========== Border Radius ========== */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-2xl: 24px;
  --radius-3xl: 32px;
  --radius-full: 9999px;

  /* ========== Shadows ========== */
  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1), 0 1px 2px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
  --shadow-inner: inset 0 2px 4px rgba(0, 0, 0, 0.06);
  --shadow-glow: 0 0 40px rgba(227, 27, 35, 0.3);
  --shadow-glow-sm: 0 0 20px rgba(227, 27, 35, 0.2);

  /* ========== Transitions ========== */
  --transition-fast: 150ms ease;
  --transition-base: 300ms ease;
  --transition-slow: 500ms ease;
  --transition-slower: 700ms ease;
  --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in-out-expo: cubic-bezier(0.87, 0, 0.13, 1);

  /* ========== Z-Index Scale ========== */
  --z-negative: -1;
  --z-0: 0;
  --z-10: 10;
  --z-20: 20;
  --z-30: 30;
  --z-40: 40;
  --z-50: 50;
  --z-header: 100;
  --z-dropdown: 200;
  --z-modal: 300;
  --z-tooltip: 400;

  /* ========== Container ========== */
  --container-sm: 640px;
  --container-md: 768px;
  --container-lg: 1024px;
  --container-xl: 1280px;
  --container-2xl: 1536px;
  --container-padding: var(--space-5);

  /* ========== Header ========== */
  --header-height: 80px;
  --header-height-scrolled: 64px;

  /* ========== Section Spacing ========== */
  --section-padding-y: var(--space-20);
  --section-padding-y-mobile: var(--space-12);
}

/* Tablet adjustments */
@media (min-width: 768px) {
  :root {
    --container-padding: var(--space-8);
  }
}

/* Desktop adjustments */
@media (min-width: 1024px) {
  :root {
    --container-padding: var(--space-10);
    --section-padding-y: var(--space-24);
  }
}