/* 
 * DA.UM 통합 디자인 시스템
 * 짙은 녹색 & 차콜 그레이 전문 교육 플랫폼
 * Version 3.0 - Dark Green & Charcoal
 */

/* ============================================
   1. 브랜드 컬러 시스템 (Dark Green & Charcoal)
   ============================================ */
:root {
    /* Dark Forest Green Colors */
    --forest-50: #f0fdf4;
    --forest-100: #dcfce7;
    --forest-200: #bbf7d0;
    --forest-300: #86efac;
    --forest-400: #4ade80;
    --forest-500: #22c55e;
    --forest-600: #16a34a;
    --forest-700: #15803d;
    --forest-800: #166534;
    --forest-900: #14532d;
    --forest-950: #052e16;
    
    /* Deep Pine Green */
    --pine-600: #0f5132;
    --pine-700: #0a3622;
    --pine-800: #052e16;
    --pine-900: #031b0d;
    
    /* Charcoal Gray Colors */
    --charcoal-50: #f9fafb;
    --charcoal-100: #f3f4f6;
    --charcoal-200: #e5e7eb;
    --charcoal-300: #d1d5db;
    --charcoal-400: #9ca3af;
    --charcoal-500: #6b7280;
    --charcoal-600: #4b5563;
    --charcoal-700: #374151;
    --charcoal-800: #2d3748;
    --charcoal-900: #1a202c;
    --charcoal-950: #0f1419;
    
    /* Primary Brand Colors */
    --brand-dark-green: #0f5132;
    --brand-forest: #15803d;
    --brand-charcoal: #2d3748;
    --brand-slate: #475569;
    
    /* Semantic Colors */
    --success: #15803d;
    --warning: #d97706;
    --error: #dc2626;
    --info: #0f5132;
    
    /* Gradients - Dark Green & Charcoal */
    --gradient-primary: linear-gradient(135deg, #0f5132 0%, #15803d 50%, #16a34a 100%);
    --gradient-dark: linear-gradient(135deg, #0f1419 0%, #2d3748 50%, #4b5563 100%);
    --gradient-hero: linear-gradient(135deg, #052e16 0%, #0f5132 30%, #15803d 70%, #16a34a 100%);
    --gradient-subtle: linear-gradient(135deg, #f0fdf4 0%, #dcfce7 100%);
    --gradient-charcoal: linear-gradient(135deg, #1a202c 0%, #2d3748 100%);
    
    /* 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);
    --shadow-green: 0 10px 30px rgba(15, 81, 50, 0.4);
    --shadow-charcoal: 0 10px 30px rgba(26, 32, 44, 0.5);
    
    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 0.75rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 0.5rem;
    --radius-md: 0.75rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    --radius-2xl: 2rem;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 300ms ease;
    --transition-slow: 500ms ease;
}

/* ============================================
   2. 기본 리셋 & 타이포그래피
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Noto Sans KR', -apple-system, BlinkMacSystemFont, sans-serif;
    background: linear-gradient(135deg, #f9fafb 0%, #e5e7eb 50%, #d1d5db 100%);
    color: var(--charcoal-900);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
}

/* ============================================
   3. 통일된 헤더 스타일 (Dark Green Gradient)
   ============================================ */
.daum-header {
    background: var(--gradient-primary);
    padding: 1.5rem 2rem;
    box-shadow: var(--shadow-lg);
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
}

.daum-header-container {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.daum-logo-section {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.daum-logo {
    display: flex;
    align-items: center;
    gap: 1rem;
    color: white;
    text-decoration: none;
}

.daum-logo img {
    width: 50px;
    height: 50px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.daum-title h1 {
    font-size: 1.75rem;
    font-weight: 900;
    color: white;
    margin: 0;
    line-height: 1.2;
}

.daum-title p {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.9);
    margin: 0;
    margin-top: 0.25rem;
}

.daum-logo-text h1 {
    font-size: 1.75rem;
    font-weight: 900;
    color: white;
    margin: 0;
}

.daum-logo-text p {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.9);
    margin: 0;
}

.daum-nav {
    display: flex;
    gap: 0.5rem;
}

.daum-nav-link {
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition-base);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.daum-nav-link:hover {
    background: rgba(255, 255, 255, 0.15);
    transform: translateY(-2px);
}

.daum-nav-link.active {
    background: rgba(255, 255, 255, 0.25);
}

/* ============================================
   4. 카드 스타일 (Glass Effect + Dark Green Accent)
   ============================================ */
.daum-card {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-2xl);
    padding: 2rem;
    box-shadow: var(--shadow-xl);
    border: 1px solid rgba(15, 81, 50, 0.1);
    transition: var(--transition-base);
}

.daum-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-green);
}

.daum-card-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--forest-100);
}

.daum-card-icon {
    width: 60px;
    height: 60px;
    background: var(--gradient-primary);
    border-radius: var(--radius-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
    color: white;
    box-shadow: var(--shadow-green);
}

.daum-card-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--pine-800);
    margin: 0;
}

/* ============================================
   5. 버튼 스타일 (Dark Green Primary)
   ============================================ */
.daum-btn {
    padding: 0.875rem 2rem;
    border-radius: var(--radius-lg);
    font-weight: 600;
    font-size: 1rem;
    border: none;
    cursor: pointer;
    transition: var(--transition-base);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
}

.daum-btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-green);
}

.daum-btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-xl);
}

.daum-btn-secondary {
    background: var(--gradient-charcoal);
    color: white;
    box-shadow: var(--shadow-charcoal);
}

.daum-btn-secondary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-xl);
}

.daum-btn-outline {
    background: transparent;
    border: 2px solid var(--brand-dark-green);
    color: var(--brand-dark-green);
}

.daum-btn-outline:hover {
    background: var(--brand-dark-green);
    color: white;
}

/* ============================================
   6. 폼 요소 스타일
   ============================================ */
.daum-input,
.daum-select,
.daum-textarea {
    width: 100%;
    padding: 0.875rem 1rem;
    border: 2px solid var(--charcoal-200);
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-family: inherit;
    transition: var(--transition-base);
    background: white;
}

.daum-input:focus,
.daum-select:focus,
.daum-textarea:focus {
    outline: none;
    border-color: var(--brand-dark-green);
    box-shadow: 0 0 0 3px rgba(15, 81, 50, 0.1);
}

/* ============================================
   7. 배지 스타일
   ============================================ */
.daum-badge {
    display: inline-flex;
    align-items: center;
    padding: 0.375rem 0.875rem;
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 600;
}

.daum-badge-success {
    background: var(--forest-100);
    color: var(--pine-800);
}

.daum-badge-warning {
    background: #fef3c7;
    color: #92400e;
}

.daum-badge-error {
    background: #fee2e2;
    color: #991b1b;
}

.daum-badge-info {
    background: var(--forest-100);
    color: var(--pine-700);
}

/* ============================================
   8. 애니메이션
   ============================================ */
@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.daum-animate-slide-up {
    animation: slideUp 0.6s ease-out;
}

.daum-animate-fade-in {
    animation: fadeIn 0.5s ease-out;
}

/* ============================================
   9. 유틸리티 클래스
   ============================================ */
.daum-text-primary {
    color: var(--brand-dark-green);
}

.daum-text-charcoal {
    color: var(--brand-charcoal);
}

.daum-bg-primary {
    background: var(--gradient-primary);
}

.daum-bg-charcoal {
    background: var(--gradient-charcoal);
}

.daum-shadow-green {
    box-shadow: var(--shadow-green);
}

.daum-shadow-charcoal {
    box-shadow: var(--shadow-charcoal);
}

/* ============================================
   10. 푸터 스타일 (Charcoal)
   ============================================ */
.daum-footer {
    background: var(--gradient-dark);
    color: var(--charcoal-100);
    padding: 3rem 2rem 2rem;
    margin-top: 4rem;
}

.daum-footer-container {
    max-width: 1400px;
    margin: 0 auto;
}

.daum-footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.daum-footer-section h4 {
    color: white;
    margin-bottom: 1rem;
    font-size: 1.125rem;
}

.daum-footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 2rem;
    text-align: center;
    color: var(--charcoal-300);
}

/* ============================================
   11. 반응형 디자인
   ============================================ */
@media (max-width: 768px) {
    .daum-header {
        padding: 1rem;
    }
    
    .daum-logo-text h1 {
        font-size: 1.25rem;
    }
    
    .daum-nav {
        display: none;
    }
    
    .daum-card {
        padding: 1.5rem;
    }
    
    .daum-card-icon {
        width: 50px;
        height: 50px;
        font-size: 1.5rem;
    }
    
    .daum-card-title {
        font-size: 1.25rem;
    }
    
    .daum-btn {
        padding: 0.75rem 1.5rem;
        font-size: 0.875rem;
    }
}

@media (max-width: 480px) {
    .daum-logo-text h1 {
        font-size: 1rem;
    }
    
    .daum-logo img {
        width: 40px;
        height: 40px;
    }
    
    .daum-card {
        padding: 1rem;
    }
    
    .daum-footer {
        padding: 2rem 1rem 1rem;
    }
}