/*
 * POSCO Group DX Growth Guide - 메인 스타일시트
 * 
 * 디자인 시스템 기반의 전역 스타일 정의
 */

/* ========================================
   CSS 변수 (컬러 시스템)
   ======================================== */
:root {
  /* Primary Colors */
  --color-primary: #1b2e50;
  --color-accent-cyan: #00a3c4;
  --color-background-light: #f8fafc;
  --color-white: #ffffff;
  
  /* Text Colors */
  --color-text-primary: #1b2e50;
  --color-text-secondary: #64748b;
  --color-text-muted: #94a3b8;
  --color-text-white: #ffffff;
  
  /* Border & Shadow */
  --border-color-default: rgba(203, 213, 225, 0.3);
  --border-color-light: rgba(255, 255, 255, 0.8);
  --border-color-accent: rgba(0, 163, 196, 0.3);
  --shadow-sm: 0 10px 30px -10px rgba(27, 46, 80, 0.05);
  --shadow-md: 0 20px 40px -15px rgba(27, 46, 80, 0.1);
  --shadow-lg: 0 30px 60px -20px rgba(27, 46, 80, 0.15);
  
  /* Glass Morphism */
  --glass-bg: rgba(255, 255, 255, 0.7);
  --glass-bg-hover: rgba(255, 255, 255, 0.95);
  --glass-blur: 12px;
  
  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
  
  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;
  --radius-2xl: 2rem;
  --radius-full: 9999px;
  
  /* Typography */
  --font-display: "Wanted Sans", "Pretendard", "Noto Sans KR", sans-serif;
  --font-body: "Wanted Sans", "Pretendard", "Noto Sans KR", "Apple SD Gothic Neo", sans-serif;
  
  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 300ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
}


/* ========================================
   CSS Reset
   ======================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  color: var(--color-text-primary);
  background-color: var(--color-background-light);
  min-height: 100vh;
  overflow-x: hidden;
}

/* 선택 영역 스타일 */
::selection {
  background-color: var(--color-accent-cyan);
  color: var(--color-white);
}

::-moz-selection {
  background-color: var(--color-accent-cyan);
  color: var(--color-white);
}


/* ========================================
   Typography
   ======================================== */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--spacing-sm);
}

h1 {
  font-size: 2.5rem;
  letter-spacing: -0.02em;
}

h2 {
  font-size: 2rem;
  letter-spacing: -0.01em;
}

h3 {
  font-size: 1.75rem;
}

h4 {
  font-size: 1.5rem;
}

h5 {
  font-size: 1.25rem;
}

h6 {
  font-size: 1rem;
}

p {
  margin-bottom: var(--spacing-sm);
  line-height: 1.7;
}

a {
  color: var(--color-accent-cyan);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-primary);
}


/* ========================================
   Utility Classes
   ======================================== */
.container {
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

@media (max-width: 768px) {
  .container {
    padding: 0 var(--spacing-md);
  }
}

.text-center {
  text-align: center;
}

.text-primary {
  color: var(--color-primary);
}

.text-accent {
  color: var(--color-accent-cyan);
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}


/* ========================================
   Button Styles
   ======================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-xs) var(--spacing-md);
  font-size: 0.9375rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
}

.btn-primary {
  background-color: var(--color-accent-cyan);
  color: var(--color-white);
}

.btn-primary:hover {
  background-color: var(--color-primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background-color: var(--color-white);
  color: var(--color-primary);
  border: 1px solid var(--border-color-default);
}

.btn-secondary:hover {
  border-color: var(--color-accent-cyan);
  color: var(--color-accent-cyan);
  transform: translateY(-2px);
}


/* ========================================
   Responsive Grid
   ======================================== */
.grid {
  display: grid;
  gap: var(--spacing-lg);
}

.grid-cols-1 {
  grid-template-columns: repeat(1, 1fr);
}

.grid-cols-2 {
  grid-template-columns: repeat(2, 1fr);
}

.grid-cols-3 {
  grid-template-columns: repeat(3, 1fr);
}

/* 반응형 브레이크포인트 */
@media (max-width: 1024px) {
  .grid-cols-3 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .grid-cols-2,
  .grid-cols-3 {
    grid-template-columns: repeat(1, 1fr);
  }
}


/* ========================================
   Animations
   ======================================== */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in {
  animation: fadeIn var(--transition-slow) ease-out;
}


/* ========================================
   Accessibility
   ======================================== */
/* 키보드 포커스 스타일 */
:focus-visible {
  outline: 2px solid var(--color-accent-cyan);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* 감소된 모션 선호 */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}