:root {
    /* Colors - Modern Enterprise Dark Theme */
    --primary-color: #007AFF;
    /* Electric Blue - Innovation */
    --primary-dark: #0056b3;
    --secondary-color: #CCFF00;
    /* Cyber Lime - Accent/Growth */
    --bg-dark: #0A192F;
    /* Deep Navy - Trust/Security */
    --bg-darker: #020c1b;
    --bg-card: rgba(255, 255, 255, 0.05);
    /* Glassmorphism base */
    --text-color: #E6F1FF;
    /* Off-white for dark bg */
    --text-muted: #8892b0;
    --white: #ffffff;
    --border-color: rgba(255, 255, 255, 0.1);

    /* Gradients */
    --gradient-hero: linear-gradient(135deg, #0A192F 0%, #112240 100%);
    --gradient-accent: linear-gradient(90deg, #007AFF, #00C6FF);

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 8rem;

    /* Typography */
    --font-heading: 'Inter', sans-serif;
    --font-body: 'Noto Sans KR', sans-serif;

    /* Shadow & Glass */
    --shadow-sm: 0 4px 6px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.5);
    --glass-border: 1px solid rgba(255, 255, 255, 0.1);
    --glass-bg: rgba(10, 25, 47, 0.7);
    --glass-backdrop: blur(10px);
}

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

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

body {
    font-family: var(--font-body);
    background-color: var(--bg-dark);
    color: var(--text-color);
    line-height: 1.6;
    overflow-x: hidden;
    /* Prevent horizontal scroll */
}

h1,
h2,
h3,
h4,
h5,
h6 {
    font-family: var(--font-heading);
    color: var(--white);
    line-height: 1.2;
    margin-bottom: var(--spacing-sm);
    font-weight: 700;
}

p {
    color: var(--text-muted);
}

a {
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}

ul {
    list-style: none;
}

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

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

/* Buttons */
.btn {
    display: inline-block;
    padding: 1rem 2.5rem;
    border-radius: 4px;
    /* More angular for tech feel */
    font-weight: 600;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.645, 0.045, 0.355, 1);
    border: none;
    font-size: 1rem;
    letter-spacing: 0.5px;
}

.btn-primary {
    background: var(--primary-color);
    color: var(--white);
    box-shadow: 0 4px 14px 0 rgba(0, 118, 255, 0.39);
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 118, 255, 0.23);
}

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

.btn-secondary:hover {
    background: rgba(0, 122, 255, 0.1);
    transform: translateY(-2px);
}

/* Glassmorphism Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: rgba(10, 25, 47, 0.85);
    /* Dark Glass */
    backdrop-filter: var(--glass-backdrop);
    border-bottom: var(--glass-border);
    z-index: 1000;
    padding: 1rem 0;
    transition: all 0.3s ease;
}

.header.scrolled {
    padding: 0.8rem 0;
    box-shadow: var(--shadow-sm);
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--white);
    letter-spacing: -0.5px;
}

.nav-list {
    display: flex;
    gap: var(--spacing-md);
}

.nav-list a {
    font-weight: 500;
    font-size: 0.95rem;
    color: var(--text-color);
    opacity: 0.8;
}

.nav-list a:hover,
.nav-list a.active {
    color: var(--primary-color);
    opacity: 1;
}

.nav-list a.active::after {
    content: '';
    display: block;
    width: 100%;
    height: 2px;
    background: var(--primary-color);
    margin-top: 4px;
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 30px;
    height: 21px;
    background: none;
    border: none;
    cursor: pointer;
}

.mobile-menu-toggle span {
    display: block;
    width: 100%;
    height: 2px;
    background-color: var(--white);
    transition: all 0.3s ease;
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: var(--bg-dark);
    position: relative;
    padding-top: 80px;
    overflow: hidden;
}

/* Abstract Background Nodes (CSS only simple version) */
.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 800px;
    height: 800px;
    background: radial-gradient(circle, rgba(0, 122, 255, 0.15) 0%, rgba(0, 0, 0, 0) 70%);
    border-radius: 50%;
    pointer-events: none;
}

.hero-content {
    max-width: 900px;
    position: relative;
    z-index: 1;
}

.hero-subtitle-top {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    display: block;
    letter-spacing: 1px;
    text-transform: uppercase;
    font-size: 0.9rem;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: var(--spacing-md);
    line-height: 1.1;
    background: linear-gradient(to right, #fff, #a5b4fc);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-desc {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-lg);
    max-width: 600px;
    color: var(--text-muted);
}

.hero-actions {
    display: flex;
    gap: var(--spacing-sm);
}

/* Sections General */
.section {
    padding: var(--spacing-xl) 0;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: var(--spacing-lg);
    position: relative;
}

.section-title span {
    color: var(--primary-color);
}

.section-subtitle {
    text-align: center;
    font-size: 1.1rem;
    color: var(--text-muted);
    margin-top: -3rem;
    margin-bottom: var(--spacing-lg);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

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

.col-3 {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.card {
    background: var(--bg-card);
    border: 1px solid rgba(255, 255, 255, 0.05);
    padding: var(--spacing-md);
    border-radius: 8px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    backdrop-filter: blur(5px);
}

.card:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
    box-shadow: 0 10px 30px -10px rgba(0, 122, 255, 0.2);
}

.card-link {
    display: block;
    height: 100%;
}

.card-image {
    width: 100%;
    height: 180px;
    object-fit: cover;
    border-radius: 8px;
    margin-bottom: 1.2rem;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

/* Remove or hide card-icon if present in context, or just style images */
.card h3 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: var(--white);
}

.card p {
    font-size: 1rem;
    color: var(--text-muted);
}

.card-icon {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--primary-color);
}

/* Technology Layer Section */
.tech-layer {
    background: var(--bg-darker);
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.tech-step {
    display: flex;
    align-items: flex-start;
    margin-bottom: var(--spacing-md);
    padding: var(--spacing-sm);
    border-radius: 8px;
}

.tech-step:hover {
    background: rgba(255, 255, 255, 0.03);
}

.tech-num {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--primary-color);
    margin-right: var(--spacing-md);
    opacity: 0.5;
}

.tech-content h4 {
    color: var(--white);
    margin-bottom: 0.5rem;
}

/* Cases Slider (Simplified as Grid for MVP) */
.cases-section {
    background: var(--bg-dark);
}

.case-preview-card {
    background: rgba(255, 255, 255, 0.03);
    /* Lighter than main bg */
    padding: var(--spacing-md);
    border-radius: 8px;
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: all 0.3s;
}

.case-preview-card:hover {
    background: rgba(255, 255, 255, 0.05);
}

.metric-highlight {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--secondary-color);
    display: block;
    margin: 1rem 0;
    line-height: 1;
}

.metric-label {
    font-size: 0.9rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Deployment Roadmap */
.roadmap-container {
    display: flex;
    justify-content: space-between;
    position: relative;
    margin-top: var(--spacing-lg);
    flex-wrap: wrap;
    gap: 2rem;
}

.roadmap-step {
    flex: 1;
    min-width: 250px;
    background: var(--bg-card);
    padding: 2rem;
    border-radius: 8px;
    position: relative;
    border-top: 3px solid var(--primary-color);
}

.roadmap-step h4 {
    margin-top: 1rem;
}

/* Call to Action */
.cta-section {
    text-align: center;
    background: linear-gradient(180deg, var(--bg-dark) 0%, #0d2546 100%);
}

.cta-box {
    max-width: 800px;
    margin: 0 auto;
    padding: var(--spacing-lg);
    border-radius: 16px;
    background: rgba(0, 122, 255, 0.05);
    border: 1px solid rgba(0, 122, 255, 0.2);
}

/* Footer */
.footer {
    background-color: #020c1b;
    color: var(--text-muted);
    padding: var(--spacing-lg) 0 var(--spacing-md);
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    font-size: 0.9rem;
}

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

.footer-info strong {
    color: var(--white);
    font-size: 1.1rem;
    display: block;
    margin-bottom: 1rem;
}

.footer-info p {
    margin-bottom: 0.5rem;
}

.copyright {
    margin-top: 2rem;
    opacity: 0.5;
    font-size: 0.8rem;
}

/* Page Headers (Sub-pages) */
.page-header {
    padding: 180px 0 80px;
    background: radial-gradient(circle at 50% 0%, rgba(0, 122, 255, 0.1) 0%, var(--bg-dark) 70%);
    text-align: center;
}

.page-header h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.page-header p {
    font-size: 1.2rem;
    color: var(--text-muted);
    font-weight: 300;
}

/* Responsive */
@media (max-width: 768px) {
    :root {
        --spacing-xl: 4rem;
        --spacing-lg: 3rem;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-actions {
        flex-direction: column;
    }

    .nav {
        position: fixed;
        top: 60px;
        left: 0;
        width: 100%;
        background: var(--bg-dark);
        padding: var(--spacing-md);
        box-shadow: 0 10px 20px rgba(0, 0, 0, 0.5);
        transform: translateY(-150%);
        border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    }

    .nav.active {
        transform: translateY(0);
    }

    .nav-list {
        flex-direction: column;
        align-items: center;
    }

    .nav-list a {
        color: var(--white);
        font-size: 1.1rem;
    }

    .mobile-menu-toggle {
        display: flex;
    }

    .roadmap-container {
        flex-direction: column;
    }
}