/* ========================================
   CSS Variables & Reset
   ======================================== */
:root {
    /* Colors - Light Mode */
    --primary: #2c3e50;
    --accent: #3498db;
    --text-primary: #2c3e50;
    --text-secondary: #7f8c8d;
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-dark: #1a1a1a;
    --border: #ecf0f1;
    
    /* Spacing */
    --sidebar-width: 280px;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;
    
    /* Typography */
    --font-primary: 'Noto Sans KR', -apple-system, sans-serif;
    --font-english: 'Poppins', sans-serif;
    
    /* Border Radius */
    --radius-sm: 0.25rem;
    --radius-md: 0.5rem;
    --radius-lg: 1rem;
    
    /* Transitions */
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.12);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.16);
}

/* Dark Mode */
body.dark-mode {
    --text-primary: #ecf0f1;
    --text-secondary: #95a5a6;
    --bg-primary: #0a0a0a;
    --bg-secondary: #1a1a1a;
    --bg-dark: #000000;
    --border: #2c2c2c;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    font-family: var(--font-primary);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    transition: background-color 0.3s ease, color 0.3s ease;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

/* ========================================
   Sidebar Navigation
   ======================================== */
.sidebar {
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    width: var(--sidebar-width);
    background: var(--bg-dark);
    color: #ffffff;
    padding: var(--spacing-lg);
    z-index: 1000;
    transition: var(--transition);
    overflow-y: auto;
}

.sidebar-header {
    margin-bottom: var(--spacing-3xl);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.logo-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, #3498db, #2980b9);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
}

.logo-text {
    font-family: var(--font-english);
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: 2px;
}

.nav-menu {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.nav-link {
    padding: var(--spacing-md);
    color: rgba(255, 255, 255, 0.7);
    transition: var(--transition);
    border-radius: var(--radius-md);
    position: relative;
    overflow: hidden;
}

.nav-link::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background: #3498db;
    transform: scaleY(0);
    transition: var(--transition);
}

.nav-link:hover,
.nav-link.active {
    color: #ffffff;
    background: rgba(255, 255, 255, 0.05);
}

.nav-link.active::before {
    transform: scaleY(1);
}

.theme-toggle {
    position: absolute;
    bottom: var(--spacing-lg);
    left: 50%;
    transform: translateX(-50%);
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: white;
    font-size: 1.2rem;
    cursor: pointer;
    transition: var(--transition);
}

.theme-toggle:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateX(-50%) scale(1.1);
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
    display: none;
    position: fixed;
    top: var(--spacing-md);
    left: var(--spacing-md);
    z-index: 1001;
    width: 50px;
    height: 50px;
    background: var(--bg-dark);
    border: none;
    border-radius: var(--radius-md);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 5px;
    cursor: pointer;
}

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background: white;
    border-radius: 3px;
    transition: var(--transition);
}

/* ========================================
   Main Content Layout
   ======================================== */
.main-content {
    margin-left: var(--sidebar-width);
    min-height: 100vh;
}

.section {
    min-height: 100vh;
    padding: var(--spacing-3xl) var(--spacing-xl);
    position: relative;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

.container-fluid {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* ========================================
   Hero Section
   ======================================== */
.hero-section {
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    inset: 0;
    background-image: url('https://images.unsplash.com/photo-1452457807411-4979b707c5be?w=1920&q=80');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
}

.hero-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.5));
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    color: white;
    max-width: 800px;
}

.hero-title {
    font-family: var(--font-english);
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    line-height: 1.2;
}

.highlight {
    background: linear-gradient(135deg, #3498db, #2ecc71);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-family: var(--font-english);
    font-size: clamp(1rem, 2vw, 1.5rem);
    font-weight: 300;
    margin-bottom: var(--spacing-lg);
    opacity: 0.9;
}

.hero-description {
    font-size: clamp(1rem, 1.5vw, 1.1rem);
    line-height: 1.8;
    margin-bottom: var(--spacing-xl);
    opacity: 0.85;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

.scroll-indicator {
    position: absolute;
    bottom: var(--spacing-xl);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    color: white;
    opacity: 0.7;
    animation: float 2s infinite ease-in-out;
}

.mouse {
    width: 25px;
    height: 40px;
    border: 2px solid white;
    border-radius: 15px;
    position: relative;
}

.mouse::before {
    content: '';
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 8px;
    background: white;
    border-radius: 2px;
    animation: scroll 1.5s infinite;
}

@keyframes float {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50% { transform: translateX(-50%) translateY(-10px); }
}

@keyframes scroll {
    0% { opacity: 1; transform: translateX(-50%) translateY(0); }
    100% { opacity: 0; transform: translateX(-50%) translateY(15px); }
}

/* ========================================
   Buttons
   ======================================== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 1rem 2rem;
    border-radius: var(--radius-lg);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    font-size: 1rem;
}

.btn-primary {
    background: linear-gradient(135deg, #3498db, #2980b9);
    color: white;
    box-shadow: 0 4px 20px rgba(52, 152, 219, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 30px rgba(52, 152, 219, 0.4);
}

.btn-outline {
    background: transparent;
    color: white;
    border: 2px solid white;
}

.btn-outline:hover {
    background: white;
    color: var(--primary);
}

.btn-full {
    width: 100%;
    justify-content: center;
}

/* ========================================
   Section Headers
   ======================================== */
.section-badge {
    display: inline-block;
    padding: 0.5rem 1rem;
    background: rgba(52, 152, 219, 0.1);
    color: var(--accent);
    border-radius: var(--radius-lg);
    font-size: 0.875rem;
    font-weight: 600;
    letter-spacing: 1px;
    margin-bottom: var(--spacing-md);
}

.section-title {
    font-family: var(--font-english);
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    margin-bottom: var(--spacing-md);
}

.section-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto var(--spacing-xl);
}

/* ========================================
   Intro Section
   ======================================== */
.intro-section {
    background: var(--bg-secondary);
}

.intro-section .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    align-items: center;
}

.intro-image {
    position: relative;
    border-radius: var(--radius-lg);
    overflow: hidden;
    height: 500px;
}

.intro-bg {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.intro-content {
    padding: var(--spacing-lg);
}

.intro-text p {
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
    color: var(--text-secondary);
}

.intro-services {
    display: flex;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.service-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    text-align: center;
}

.service-item i {
    font-size: 2rem;
    color: var(--accent);
    margin-bottom: var(--spacing-xs);
}

/* ========================================
   About CEO Section
   ======================================== */
.about-section {
    background: var(--bg-primary);
}

.about-header {
    text-align: center;
    margin-bottom: var(--spacing-3xl);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--spacing-3xl);
    align-items: start;
}

.ceo-card {
    background: var(--bg-dark);
    color: white;
    padding: var(--spacing-3xl) var(--spacing-xl);
    border-radius: var(--radius-lg);
    text-align: center;
    min-height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.ceo-logo i {
    font-size: 4rem;
    background: linear-gradient(135deg, #3498db, #2ecc71);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: var(--spacing-md);
}

.ceo-logo span {
    display: block;
    font-family: var(--font-english);
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: 2px;
    margin-bottom: var(--spacing-sm);
}

.ceo-logo p {
    font-family: var(--font-english);
    font-size: 0.875rem;
    opacity: 0.7;
}

.bio-section {
    margin-bottom: var(--spacing-xl);
}

.bio-section h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
    color: var(--accent);
}

.bio-section ul {
    padding-left: var(--spacing-md);
}

.bio-section li {
    margin-bottom: var(--spacing-sm);
    line-height: 1.8;
    color: var(--text-secondary);
    position: relative;
    padding-left: var(--spacing-md);
}

.bio-section li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--accent);
}

/* ========================================
   History Timeline
   ======================================== */
.history-section {
    background: var(--bg-secondary);
}

.history-header {
    text-align: center;
    margin-bottom: var(--spacing-3xl);
}

.timeline {
    max-width: 800px;
    margin: 0 auto;
    position: relative;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 100px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--border);
}

.timeline-item {
    display: grid;
    grid-template-columns: 100px 1fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
    position: relative;
}

.timeline-year {
    font-family: var(--font-english);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent);
    text-align: right;
}

.timeline-content {
    padding: var(--spacing-md);
    background: var(--bg-primary);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    position: relative;
}

.timeline-content::before {
    content: '';
    position: absolute;
    left: -8px;
    top: 20px;
    width: 16px;
    height: 16px;
    background: var(--accent);
    border-radius: 50%;
    border: 3px solid var(--bg-primary);
}

.timeline-month {
    font-weight: 700;
    color: var(--accent);
    margin-bottom: var(--spacing-xs);
}

/* ========================================
   Projects Grid
   ======================================== */
.projects-section {
    background: var(--bg-primary);
}

.projects-header {
    text-align: center;
    margin-bottom: var(--spacing-3xl);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-lg);
}

.project-card {
    position: relative;
    overflow: hidden;
    border-radius: var(--radius-lg);
    cursor: pointer;
    aspect-ratio: 4/3;
}

.project-image {
    position: relative;
    width: 100%;
    height: 100%;
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition-slow);
}

.project-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(to top, rgba(0, 0, 0, 0.9), transparent);
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    padding: var(--spacing-lg);
    color: white;
    opacity: 0;
    transition: var(--transition);
}

.project-card:hover .project-image img {
    transform: scale(1.1);
}

.project-card:hover .project-overlay {
    opacity: 1;
}

.project-overlay h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-xs);
}

.project-overlay p {
    font-size: 0.875rem;
    opacity: 0.8;
}

/* ========================================
   Gallery Grid
   ======================================== */
.gallery-section {
    background: var(--bg-secondary);
}

.gallery-header {
    text-align: center;
    margin-bottom: var(--spacing-3xl);
}

.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
}

.gallery-item {
    position: relative;
    overflow: hidden;
    border-radius: var(--radius-md);
    cursor: pointer;
    aspect-ratio: 1;
    background: var(--bg-primary);
}

.gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition-slow);
}

.gallery-item:hover img {
    transform: scale(1.05);
}

/* ========================================
   Clients Section
   ======================================== */
.clients-section {
    background: var(--bg-primary);
    padding: var(--spacing-3xl) var(--spacing-xl);
}

.clients-header {
    text-align: center;
    margin-bottom: var(--spacing-3xl);
}

.clients-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-lg);
}

.client-item {
    padding: var(--spacing-xl);
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    text-align: center;
    font-weight: 600;
    font-size: 1.125rem;
    transition: var(--transition);
}

.client-item:hover {
    background: var(--accent);
    color: white;
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

/* ========================================
   Contact Section
   ======================================== */
.contact-section {
    background: var(--bg-secondary);
}

.contact-header {
    text-align: center;
    margin-bottom: var(--spacing-3xl);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    margin-bottom: var(--spacing-3xl);
}

.info-item {
    display: flex;
    gap: var(--spacing-md);
    padding: var(--spacing-lg);
    background: var(--bg-primary);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-md);
    transition: var(--transition);
}

.info-item:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow-md);
}

.info-icon {
    width: 50px;
    height: 50px;
    min-width: 50px;
    background: linear-gradient(135deg, #3498db, #2980b9);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.25rem;
}

.info-text h4 {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
}

.info-text p {
    font-weight: 600;
}

.contact-form-wrapper {
    background: var(--bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
}

.form-group {
    margin-bottom: var(--spacing-md);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: var(--spacing-md);
    border: 2px solid var(--border);
    border-radius: var(--radius-md);
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 4px rgba(52, 152, 219, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 150px;
}

.map-wrapper {
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.map-placeholder {
    width: 100%;
    height: 450px;
}

/* ========================================
   Footer
   ======================================== */
.footer {
    background: var(--bg-dark);
    color: white;
    padding: var(--spacing-xl);
    text-align: center;
}

.footer-logo {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-family: var(--font-english);
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.footer-logo i {
    font-size: 2rem;
}

.footer-text {
    font-family: var(--font-english);
    opacity: 0.7;
    margin-bottom: var(--spacing-xs);
}

.footer-copyright {
    font-size: 0.875rem;
    opacity: 0.5;
}

/* ========================================
   Lightbox
   ======================================== */
.lightbox {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.95);
    z-index: 9999;
    align-items: center;
    justify-content: center;
}

.lightbox.active {
    display: flex;
}

.lightbox-close,
.lightbox-prev,
.lightbox-next {
    position: absolute;
    background: rgba(255, 255, 255, 0.1);
    border: none;
    color: white;
    font-size: 2rem;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    cursor: pointer;
    transition: var(--transition);
}

.lightbox-close {
    top: var(--spacing-lg);
    right: var(--spacing-lg);
}

.lightbox-prev {
    left: var(--spacing-lg);
}

.lightbox-next {
    right: var(--spacing-lg);
}

.lightbox-close:hover,
.lightbox-prev:hover,
.lightbox-next:hover {
    background: rgba(255, 255, 255, 0.2);
}

#lightboxImage {
    max-width: 90%;
    max-height: 90%;
    object-fit: contain;
}

/* ========================================
   Animations
   ======================================== */
[data-aos] {
    opacity: 0;
    transition: var(--transition-slow);
}

[data-aos].aos-animate {
    opacity: 1;
}

[data-aos="fade-up"] {
    transform: translateY(30px);
}

[data-aos="fade-up"].aos-animate {
    transform: translateY(0);
}

[data-aos="fade-left"] {
    transform: translateX(30px);
}

[data-aos="fade-left"].aos-animate {
    transform: translateX(0);
}

[data-aos="fade-right"] {
    transform: translateX(-30px);
}

[data-aos="fade-right"].aos-animate {
    transform: translateX(0);
}

/* ========================================
   Responsive Design
   ======================================== */
@media (max-width: 1024px) {
    :root {
        --sidebar-width: 280px;
    }
    
    .sidebar {
        transform: translateX(-100%);
        box-shadow: 2px 0 20px rgba(0, 0, 0, 0.3);
    }
    
    .sidebar.active {
        transform: translateX(0);
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .main-content {
        margin-left: 0;
    }
    
    .intro-section .container,
    .about-content,
    .contact-content {
        grid-template-columns: 1fr;
    }
    
    .projects-grid {
        grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    }
}

@media (max-width: 768px) {
    .section {
        padding: var(--spacing-xl) var(--spacing-md);
    }
    
    .hero-buttons {
        flex-direction: column;
    }
    
    .timeline::before {
        left: 50px;
    }
    
    .timeline-item {
        grid-template-columns: 50px 1fr;
    }
    
    .projects-grid,
    .gallery-grid {
        grid-template-columns: 1fr;
    }
    
    .clients-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}