/* ==========================================
   NA.DERPNERD.COM - Minimal Clean Style
========================================== */

/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-card: #ffffff;
    --text-primary: #1a202c;
    --text-secondary: #718096;
    --accent: #2d3748;
    --accent-hover: #1a202c;
    --border: #e2e8f0;
    --mint: #0891b2;
    --mint-hover: #0e7490;
    --gradient-1: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-2: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
    --shadow-lg: 0 10px 20px rgba(0, 0, 0, 0.1);
    
    /* Typography */
    --font-main: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Malgun Gothic', sans-serif;
    --font-mono: 'SF Mono', Monaco, 'Cascadia Code', monospace;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 3rem;
    --spacing-xl: 4rem;
    
    /* Container */
    --container-max: 1000px;
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-main);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Container */
.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* Navigation */
nav {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    padding: var(--spacing-md) 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.nav-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
    letter-spacing: -0.02em;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.nav-logo:hover {
    color: var(--mint);
    transform: translateY(-1px);
}

.nav-links {
    display: flex;
    gap: 2rem;
    list-style: none;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.95rem;
    font-weight: 500;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    padding: 0.5rem 0;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--mint);
    transition: width 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--text-primary);
}

.nav-links a:hover::after,
.nav-links a.active::after {
    width: 100%;
}

/* Main Content */
main {
    min-height: calc(100vh - 200px);
    padding: var(--spacing-xl) 0;
}

/* Typography */
h1 {
    font-size: 3rem;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
    letter-spacing: -0.03em;
}

h2 {
    font-size: 2rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-sm);
    margin-top: var(--spacing-lg);
    color: var(--text-primary);
    letter-spacing: -0.02em;
}

h3 {
    font-size: 1.4rem;
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
    letter-spacing: -0.01em;
}

p {
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
    line-height: 1.8;
    font-size: 1.05rem;
}

/* Sections */
.section {
    margin-bottom: var(--spacing-xl);
}

.section-title {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-sm);
    border-bottom: 3px solid var(--border);
    color: var(--text-primary);
    position: relative;
    letter-spacing: -0.02em;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -3px;
    left: 0;
    width: 60px;
    height: 3px;
    background: var(--gradient-1);
}

/* Lists */
ul, ol {
    margin-left: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
}

li {
    margin-bottom: var(--spacing-xs);
    color: var(--text-secondary);
}

/* Links */
a {
    color: var(--mint);
    text-decoration: none;
}

a:hover {
    color: var(--mint-hover);
    text-decoration: underline;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    background: var(--accent);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    text-decoration: none;
    box-shadow: var(--shadow-md);
    letter-spacing: 0.01em;
}

.btn:hover {
    background: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-mint {
    background: var(--gradient-1);
}

.btn-mint:hover {
    background: linear-gradient(135deg, #764ba2 0%, #667eea 100%);
}

.btn-outline {
    background: transparent;
    color: var(--accent);
    border: 2px solid var(--accent);
    box-shadow: none;
}

.btn-outline:hover {
    background: var(--accent);
    color: white;
    box-shadow: var(--shadow-md);
}

/* Cards */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 2rem;
    margin-bottom: var(--spacing-md);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: var(--shadow-sm);
}

.card:hover {
    border-color: transparent;
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

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

.grid-2 {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

/* Tags */
.tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: var(--spacing-sm);
}

.tag {
    display: inline-block;
    padding: 0.375rem 1rem;
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    color: var(--text-secondary);
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
    border: 1px solid var(--border);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.tag:hover {
    background: linear-gradient(135deg, #e9ecef 0%, #dee2e6 100%);
    color: var(--text-primary);
    transform: translateY(-1px);
    box-shadow: var(--shadow-sm);
}

/* Footer */
footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    padding: var(--spacing-lg) 0;
    margin-top: var(--spacing-xl);
    text-align: center;
}

footer p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Utilities */
.text-center { text-align: center; }
.text-muted { color: var(--text-secondary); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mt-lg { margin-top: var(--spacing-lg); }

/* Responsive */
@media (max-width: 768px) {
    html {
        font-size: 14px;
    }
    
    h1 {
        font-size: 2.25rem;
    }
    
    h2 {
        font-size: 1.75rem;
    }
    
    .nav-container {
        flex-direction: column;
        gap: var(--spacing-sm);
    }
    
    .nav-links {
        flex-wrap: wrap;
        justify-content: center;
        gap: 1.5rem;
    }
    
    .grid-2 {
        grid-template-columns: 1fr;
    }
    
    .card {
        padding: 1.5rem;
    }
}

/* Print Styles */
@media print {
    nav, footer {
        display: none;
    }
    
    main {
        padding: 0;
    }
    
    .btn {
        display: none;
    }
}

/* Timeline Styles */
.timeline-section {
    margin: 4rem 0;
    padding: 3rem 0;
    background: linear-gradient(to bottom, transparent, var(--bg-secondary), transparent);
}

.timeline-container {
    position: relative;
    max-width: 100%;
    margin: 0 auto;
    padding: 2rem 0;
}

/* 가로 라인 */
.timeline-line {
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(to right, 
        transparent,
        var(--border) 10%,
        var(--border) 90%,
        transparent
    );
    transform: translateY(-50%);
}

/* 타임라인 아이템들 */
.timeline-items {
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
    gap: 2rem;
    overflow-x: auto;
    padding: 0 2rem;
    scroll-behavior: smooth;
}

.timeline-items::-webkit-scrollbar {
    height: 6px;
}

.timeline-items::-webkit-scrollbar-track {
    background: var(--bg-secondary);
    border-radius: 3px;
}

.timeline-items::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 3px;
}

.timeline-items::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}

/* 타임라인 아이템 */
.timeline-item {
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    min-width: 200px;
    flex-shrink: 0;
}

/* 아이콘 점 */
.timeline-dot {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--bg-card);
    border: 3px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    z-index: 2;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: var(--shadow-sm);
    cursor: pointer;
}

.timeline-item:hover .timeline-dot {
    transform: scale(1.2);
    border-color: var(--mint);
    box-shadow: var(--shadow-md);
}

/* 타입별 색상 */
.timeline-item[data-type="career"] .timeline-dot {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-color: #667eea;
    color: white;
}

.timeline-item[data-type="project"] .timeline-dot {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    border-color: #f093fb;
    color: white;
}

.timeline-item[data-type="education"] .timeline-dot {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    border-color: #4facfe;
    color: white;
}

/* 컨텐츠 카드 */
.timeline-content {
    position: absolute;
    top: 70px;
    min-width: 250px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    box-shadow: var(--shadow-md);
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 10;
}

.timeline-item:hover .timeline-content {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.timeline-date {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--mint);
    margin-bottom: 0.5rem;
    font-family: var(--font-mono);
}

.timeline-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    line-height: 1.3;
}

.timeline-description {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* 반응형 */
@media (max-width: 768px) {
    .timeline-items {
        justify-content: flex-start;
        padding: 0 1rem;
    }
    
    .timeline-item {
        min-width: 150px;
    }
    
    .timeline-dot {
        width: 40px;
        height: 40px;
        font-size: 1.25rem;
    }
    
    .timeline-content {
        min-width: 200px;
        padding: 1rem;
    }
}