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

:root {
    /* Color Palette */
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --accent-color: #3b82f6;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-light: #9ca3af;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-dark: #111827;
    --border-color: #e5e7eb;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    
    /* Typography */
    --font-primary: 'Noto Sans KR', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-secondary: 'Roboto', sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* 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);
    
    /* Border Radius */
    --radius-sm: 0.25rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;
}

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

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

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ===================================
   Header Styles
   =================================== */
.header {
    position: sticky;
    top: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: all var(--transition-base);
}

.header.scrolled {
    box-shadow: var(--shadow-md);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) 0;
}

.logo a {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
    letter-spacing: -0.5px;
    transition: color var(--transition-base);
}

.logo a:hover {
    color: var(--secondary-color);
}

.nav-list {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
}

.nav-list a {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
    position: relative;
}

.nav-list a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transform: translateX(-50%);
    transition: width var(--transition-base);
}

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

.nav-list a:hover::after,
.nav-list a.active::after {
    width: 80%;
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
}

.mobile-menu-toggle span {
    width: 25px;
    height: 2px;
    background: var(--text-primary);
    transition: all var(--transition-base);
}

/* ===================================
   Hero Section
   =================================== */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: var(--spacing-3xl) 0 var(--spacing-2xl);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="rgba(255,255,255,0.05)" d="M0,96L48,112C96,128,192,160,288,160C384,160,480,128,576,112C672,96,768,96,864,112C960,128,1056,160,1152,160C1248,160,1344,128,1392,112L1440,96L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>') no-repeat bottom;
    background-size: cover;
    opacity: 0.3;
}

.hero-content {
    position: relative;
    z-index: 1;
}

.breadcrumb {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 0.9rem;
    margin-bottom: var(--spacing-md);
    opacity: 0.9;
}

.breadcrumb a {
    color: white;
    text-decoration: none;
    transition: opacity var(--transition-base);
}

.breadcrumb a:hover {
    opacity: 0.8;
    text-decoration: underline;
}

.breadcrumb .separator {
    opacity: 0.6;
}

.breadcrumb .current {
    font-weight: 600;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 900;
    margin-bottom: var(--spacing-md);
    line-height: 1.1;
    letter-spacing: -1px;
}

.hero-subtitle {
    font-size: 1.25rem;
    opacity: 0.95;
    font-weight: 300;
}

/* ===================================
   Project Info Section
   =================================== */
.project-info {
    background: var(--bg-secondary);
    padding: var(--spacing-2xl) 0;
    border-bottom: 1px solid var(--border-color);
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
}

.info-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

.info-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.info-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: white;
    flex-shrink: 0;
}

.info-content {
    flex: 1;
}

.info-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-weight: 500;
    margin-bottom: var(--spacing-xs);
}

.info-value {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
}

/* ===================================
   Main Content Section
   =================================== */
.main-content {
    padding: var(--spacing-3xl) 0;
}

.content-section {
    margin-bottom: var(--spacing-3xl);
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-lg);
    position: relative;
    padding-bottom: var(--spacing-sm);
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    border-radius: var(--radius-full);
}

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

/* Gallery Grid */
.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.gallery-item {
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
}

.gallery-item:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.gallery-image {
    width: 100%;
    height: 300px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: white;
    position: relative;
    overflow: hidden;
}

.gallery-image::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.2);
    z-index: 1;
}

.gallery-image i {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
    opacity: 0.8;
    position: relative;
    z-index: 2;
}

.gallery-image span {
    font-size: 1.125rem;
    font-weight: 500;
    position: relative;
    z-index: 2;
}

/* Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.feature-card {
    background: white;
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
}

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

.feature-icon {
    width: 70px;
    height: 70px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: white;
    margin-bottom: var(--spacing-md);
}

.feature-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.feature-description {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Tech Tags */
.tech-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.tech-tag {
    background: var(--bg-secondary);
    color: var(--text-primary);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-full);
    font-size: 0.95rem;
    font-weight: 500;
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
    cursor: default;
}

.tech-tag:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

/* Results Grid */
.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: var(--spacing-lg);
}

.result-card {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: white;
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-base);
}

.result-card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: var(--shadow-xl);
}

.result-number {
    font-size: 3rem;
    font-weight: 900;
    margin-bottom: var(--spacing-sm);
    line-height: 1;
}

.result-label {
    font-size: 1rem;
    opacity: 0.95;
    font-weight: 500;
}

/* Testimonial */
.testimonial {
    background: var(--bg-secondary);
    padding: var(--spacing-2xl);
    border-radius: var(--radius-xl);
    border-left: 4px solid var(--primary-color);
    position: relative;
}

.testimonial-icon {
    font-size: 3rem;
    color: var(--primary-color);
    opacity: 0.2;
    margin-bottom: var(--spacing-md);
}

.testimonial-text {
    font-size: 1.125rem;
    line-height: 1.8;
    color: var(--text-primary);
    margin-bottom: var(--spacing-lg);
    font-style: italic;
}

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

.author-name {
    font-weight: 700;
    color: var(--text-primary);
    font-size: 1.125rem;
}

.author-position {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* CTA Box */
.cta-box {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: var(--spacing-3xl);
    border-radius: var(--radius-xl);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.cta-box::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
    animation: pulse 4s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); opacity: 0.5; }
    50% { transform: scale(1.1); opacity: 0.8; }
}

.cta-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    position: relative;
    z-index: 1;
}

.cta-text {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xl);
    opacity: 0.95;
    position: relative;
    z-index: 1;
}

.cta-buttons {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
    position: relative;
    z-index: 1;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-xl);
    border-radius: var(--radius-lg);
    font-weight: 600;
    text-decoration: none;
    transition: all var(--transition-base);
    cursor: pointer;
    border: 2px solid transparent;
    font-size: 1rem;
}

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

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

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

.btn-secondary:hover {
    background: var(--bg-secondary);
    transform: translateY(-2px);
}

/* ===================================
   Footer Styles
   =================================== */
.footer {
    background: var(--bg-dark);
    color: white;
    padding: var(--spacing-3xl) 0 var(--spacing-lg);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-section {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.footer-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
}

.footer-text {
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.8;
}

.footer-heading {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.footer-links {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: color var(--transition-base);
}

.footer-links a:hover {
    color: white;
}

.social-links {
    display: flex;
    gap: var(--spacing-md);
}

.social-links a {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    text-decoration: none;
    transition: all var(--transition-base);
}

.social-links a:hover {
    background: var(--primary-color);
    transform: translateY(-4px);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: var(--spacing-lg);
    text-align: center;
    color: rgba(255, 255, 255, 0.6);
}

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 968px) {
    .hero-title {
        font-size: 2.5rem;
    }
    
    .section-title {
        font-size: 1.75rem;
    }
    
    .info-grid {
        grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    }
    
    .features-grid {
        grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    }
}

@media (max-width: 768px) {
    .nav-list {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: var(--spacing-lg);
        box-shadow: var(--shadow-lg);
        gap: var(--spacing-sm);
    }
    
    .nav-list.active {
        display: flex;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .mobile-menu-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(7px, 7px);
    }
    
    .mobile-menu-toggle.active span:nth-child(2) {
        opacity: 0;
    }
    
    .mobile-menu-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(6px, -6px);
    }
    
    .hero {
        padding: var(--spacing-2xl) 0 var(--spacing-xl);
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1.05rem;
    }
    
    .section-title {
        font-size: 1.5rem;
    }
    
    .info-grid {
        grid-template-columns: 1fr;
    }
    
    .gallery-grid {
        grid-template-columns: 1fr;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .results-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .result-number {
        font-size: 2rem;
    }
    
    .cta-box {
        padding: var(--spacing-xl);
    }
    
    .cta-title {
        font-size: 1.5rem;
    }
    
    .cta-buttons {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .hero-title {
        font-size: 1.75rem;
    }
    
    .info-item {
        flex-direction: column;
        text-align: center;
    }
    
    .feature-card {
        padding: var(--spacing-lg);
    }
    
    .results-grid {
        grid-template-columns: 1fr;
    }
    
    .testimonial {
        padding: var(--spacing-lg);
    }
}

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

.fade-in {
    animation: fadeIn 0.6s ease-out;
}

/* Scroll Animations */
.scroll-reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease-out;
}

.scroll-reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* Loading State */
.loading {
    position: relative;
    pointer-events: none;
}

.loading::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 20px;
    height: 20px;
    border: 2px solid var(--primary-color);
    border-top-color: transparent;
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
    transform: translate(-50%, -50%);
}

@keyframes spin {
    to { transform: translate(-50%, -50%) rotate(360deg); }
}