/* ==========================================================================
   CSS Variables - SI Company Design System
   신뢰감 있는 SI 회사 디자인 시스템
   ========================================================================== */

:root {
  /* ========== Colors ========== */
  /* Primary - Cyan Teal */
  --color-primary-900: #188191;
  --color-primary-800: #1B93A6;
  --color-primary-700: #1FA6BA;
  --color-primary-600: #22B8CF;
  --color-primary-500: #38BFD4;
  --color-primary-400: #4EC6D9;
  --color-primary-300: #64CDDD;
  --color-primary-200: #7AD4E2;
  --color-primary-100: #91DCE7;
  --color-primary-50: #A7E3EC;
  --color-primary-0: #ecfcff;

  /* Secondary - Gray (보수적/안정적) */
  --color-gray-900: #1a1a1a;
  --color-gray-800: #2d2d2d;
  --color-gray-700: #404040;
  --color-gray-600: #595959;
  --color-gray-500: #737373;
  --color-gray-400: #8c8c8c;
  --color-gray-300: #b3b3b3;
  --color-gray-200: #d9d9d9;
  --color-gray-100: #ededed;
  --color-gray-50: #f7f7f7;

  /* Accent - Subtle Blue for CTAs */
  --color-accent: #2563eb;
  --color-accent-hover: #1d4ed8;
  --color-accent-light: #dbeafe;
  --color-bg-theme-hover: var(--color-primary-700);

  /* Semantic Colors */
  --color-success: #059669;
  --color-warning: #d97706;
  --color-error: #dc2626;
  --color-info: #0284c7;

  /* Background & Surface */
  --color-bg-primary: #ffffff;
  --color-bg-secondary: #f8fafc;
  --color-bg-tertiary: #f1f5f9;
  --color-bg-dark: var(--color-primary-900);
  --color-bg-theme: var(--color-primary-600);

  /* Text */
  --color-text-primary: var(--color-gray-900);
  --color-text-secondary: var(--color-gray-600);
  --color-text-muted: var(--color-gray-500);
  --color-text-inverse: #ffffff;

  /* Border */
  --color-border: var(--color-gray-200);
  --color-border-light: var(--color-gray-100);
  --color-border-dark: var(--color-gray-300);

  /* ========== Typography ========== */
  --font-family-sans: 'Pretendard', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Noto Sans KR', sans-serif;
  --font-family-heading: 'Pretendard', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Noto Sans KR', sans-serif;

  /* Font Sizes */
  --font-size-xs: 0.8125rem;    /* 13px */
  --font-size-sm: 0.9375rem;    /* 15px */
  --font-size-base: 1.0625rem;  /* 17px */
  --font-size-lg: 1.1875rem;    /* 19px */
  --font-size-xl: 1.375rem;     /* 22px */
  --font-size-2xl: 1.625rem;    /* 26px */
  --font-size-3xl: 2rem;        /* 32px */
  --font-size-4xl: 2.5rem;      /* 40px */
  --font-size-5xl: 3.25rem;     /* 52px */
  --font-size-6xl: 4rem;        /* 64px */

  /* Font Weights */
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --font-weight-extrabold: 800;

  /* Line Heights (넉넉한 줄간격) */
  --line-height-tight: 1.25;
  --line-height-snug: 1.375;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;
  --line-height-loose: 2;

  /* Letter Spacing */
  --letter-spacing-tight: -0.02em;
  --letter-spacing-normal: 0;
  --letter-spacing-wide: 0.02em;

  /* ========== Spacing ========== */
  --spacing-1: 0.25rem;   /* 4px */
  --spacing-2: 0.5rem;    /* 8px */
  --spacing-3: 0.75rem;   /* 12px */
  --spacing-4: 1rem;      /* 16px */
  --spacing-5: 1.25rem;   /* 20px */
  --spacing-6: 1.5rem;    /* 24px */
  --spacing-8: 2rem;      /* 32px */
  --spacing-10: 2.5rem;   /* 40px */
  --spacing-12: 3rem;     /* 48px */
  --spacing-16: 4rem;     /* 64px */
  --spacing-20: 5rem;     /* 80px */
  --spacing-24: 6rem;     /* 96px */
  --spacing-28: 7rem;     /* 112px */
  --spacing-32: 8rem;     /* 128px */

  /* ========== Layout ========== */
  --container-max-width: 1440px;
  --container-padding: var(--spacing-6);

  /* ========== Border Radius ========== */
  --radius-sm: 0.25rem;   /* 4px */
  --radius-md: 0.5rem;    /* 8px */
  --radius-lg: 0.75rem;   /* 12px */
  --radius-xl: 1rem;      /* 16px */
  --radius-2xl: 1.5rem;   /* 24px */
  --radius-full: 9999px;

  /* ========== Shadows ========== */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);

  /* ========== Transitions ========== */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow: 350ms ease;
  --transition-slower: 550ms ease;
  --transition-slowest: 750ms ease;

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

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
  :root {
    --transition-fast: 0ms;
    --transition-normal: 0ms;
    --transition-slow: 0ms;
  }
}

/* Responsive Container Padding */
@media (max-width: 768px) {
  :root {
    --container-padding: var(--spacing-4);
  }
}