:root {
    --primary: #0a0f0d;
    --secondary: #1a2e25;
    --accent: #d4af37;
    --accent-glow: rgba(212, 175, 55, 0.4);
    --background: #050807;
    --surface: rgba(255, 255, 255, 0.03);
    --surface-hover: rgba(212, 175, 55, 0.08);
    --text: #e8ece9;
    --muted: #8a9c94;
    --gradient-1: linear-gradient(135deg, #d4af37 0%, #f5d76e 100%);
    --gradient-2: linear-gradient(135deg, #1a2e25 0%, #0a0f0d 100%);
    --glass-border: rgba(212, 175, 55, 0.15);
    --shadow-3d: 0 20px 40px rgba(0, 0, 0, 0.5), 0 0 20px rgba(212, 175, 55, 0.1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    background-color: var(--background);
    color: var(--text);
    line-height: 1.7;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.progress-bar {
    position: fixed;
    top: 0;
    left: 0;
    height: 3px;
    background: var(--gradient-1);
    width: 0%;
    z-index: 1001;
    transition: width 0.1s;
}

.glass-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(10, 15, 13, 0.7);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--glass-border);
    transition: all 0.3s ease;
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo-text {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text);
    text-decoration: none;
    letter-spacing: -0.5px;
}

.logo-text .accent {
    color: var(--accent);
    text-shadow: 0 0 10px var(--accent-glow);
}

.desktop-nav {
    display: flex;
    gap: 30px;
    align-items: center;
}

.desktop-nav a {
    color: var(--text);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
    font-size: 0.95rem;
}

.desktop-nav a:hover {
    color: var(--accent);
}

.btn-primary {
    background: var(--gradient-1);
    color: var(--primary);
    padding: 10px 24px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    display: inline-block;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(212, 175, 55, 0.3);
}

.btn-secondary {
    background: transparent;
    color: var(--accent);
    padding: 10px 24px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    border: 1px solid var(--accent);
    transition: all 0.3s ease;
    display: inline-block;
}

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

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.mobile-menu-btn span {
    width: 25px;
    height: 2px;
    background: var(--text);
    transition: all 0.3s;
}

.mobile-nav {
    display: none;
    flex-direction: column;
    background: rgba(10, 15, 13, 0.95);
    backdrop-filter: blur(12px);
    padding: 20px;
    border-bottom: 1px solid var(--glass-border);
}

.mobile-nav.active {
    display: flex;
}

.mobile-nav a {
    color: var(--text);
    text-decoration: none;
    padding: 12px 0;
    border-bottom: 1px solid var(--glass-border);
    font-weight: 500;
}

.hero-3d {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
    padding-top: 70px;
}

.hero-bg-grid {
    position: absolute;
    inset: 0;
    background-image: 
        linear-gradient(rgba(212, 175, 55, 0.05) 1px, transparent 1px),
        linear-gradient(90deg, rgba(212, 175, 55, 0.05) 1px, transparent 1px);
    background-size: 60px 60px;
    perspective: 1000px;
    transform: rotateX(60deg) scale(2);
    transform-origin: center top;
    opacity: 0.6;
}

.hero-particles {
    position: absolute;
    inset: 0;
    overflow: hidden;
}

.particle {
    position: absolute;
    width: 3px;
    height: 3px;
    background: var(--accent);
    border-radius: 50%;
    opacity: 0.6;
    animation: float 15s infinite linear;
}

@keyframes float {
    0% { transform: translateY(100vh) translateX(0); opacity: 0; }
    10% { opacity: 0.6; }
    90% { opacity: 0.6; }
    100% { transform: translateY(-100px) translateX(50px); opacity: 0; }
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    position: relative;
    z-index: 2;
}

.hero-tag {
    display: inline-block;
    padding: 6px 16px;
    background: rgba(212, 175, 55, 0.1);
    border: 1px solid var(--accent);
    color: var(--accent);
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 20px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.hero-text h1 {
    font-size: 3.2rem;
    line-height: 1.15;
    margin-bottom: 20px;
    background: linear-gradient(to right, #fff, var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.15rem;
    color: var(--muted);
    margin-bottom: 30px;
    max-width: 500px;
}

.hero-cta-group {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
}

.hero-visual {
    position: relative;
    width: 400px;
    height: 400px;
    display: flex;
    justify-content: center;
    align-items: center;
    perspective: 1000px;
    transform-style: preserve-3d;
}

.ring {
    position: absolute;
    border-radius: 50%;
    border: 1px solid rgba(212, 175, 55, 0.3);
    box-shadow: 0 0 15px rgba(212, 175, 55, 0.1);
}

.ring-1 {
    width: 300px;
    height: 300px;
    animation: rotate3d 12s linear infinite;
}

.ring-2 {
    width: 350px;
    height: 350px;
    border-color: rgba(245, 215, 110, 0.2);
    animation: rotate3d 18s linear infinite reverse;
}

.ring-3 {
    width: 400px;
    height: 400px;
    border-style: dashed;
    animation: rotate3d 25s linear infinite;
}

@keyframes rotate3d {
    0% { transform: rotateX(60deg) rotateZ(0deg); }
    100% { transform: rotateX(60deg) rotateZ(360deg); }
}

.center-logo {
    position: relative;
    width: 150px;
    height: 150px;
    display: flex;
    justify-content: center;
    align-items: center;
    transform-style: preserve-3d;
    animation: floatLogo 6s ease-in-out infinite;
}

@keyframes floatLogo {
    0%, 100% { transform: translateY(0) rotateY(0deg); }
    50% { transform: translateY(-20px) rotateY(10deg); }
}

.logo-kr {
    font-size: 3.5rem;
    font-weight: 900;
    color: #fff;
    text-shadow: 
        0 0 10px var(--accent),
        0 0 20px var(--accent),
        0 0 40px var(--accent);
    z-index: 2;
}

.glow-orb {
    position: absolute;
    width: 120px;
    height: 120px;
    background: var(--accent);
    border-radius: 50%;
    filter: blur(50px);
    opacity: 0.3;
    z-index: 1;
}

.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    color: var(--muted);
    font-size: 0.85rem;
    animation: bounce 2s infinite;
}

.mouse {
    width: 26px;
    height: 40px;
    border: 2px solid var(--muted);
    border-radius: 13px;
    position: relative;
}

.wheel {
    width: 4px;
    height: 8px;
    background: var(--accent);
    border-radius: 2px;
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    animation: scrollWheel 2s infinite;
}

@keyframes scrollWheel {
    0% { opacity: 1; top: 8px; }
    100% { opacity: 0; top: 20px; }
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
    40% { transform: translateX(-50%) translateY(-10px); }
    60% { transform: translateX(-50%) translateY(-5px); }
}

.content-section {
    padding: 80px 20px;
}

.layout-grid {
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 40px;
}

.glass-card {
    background: var(--surface);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 30px;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.glass-card:hover {
    background: var(--surface-hover);
    border-color: rgba(212, 175, 55, 0.4);
    transform: translateY(-5px);
    box-shadow: var(--shadow-3d);
}

.toc-sidebar {
    position: sticky;
    top: 100px;
    height: fit-content;
}

.toc-card h3 {
    color: var(--accent);
    margin-bottom: 20px;
    font-size: 1.1rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

#tocNav {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

#tocNav a {
    color: var(--muted);
    text-decoration: none;
    font-size: 0.9rem;
    padding-left: 15px;
    border-left: 2px solid transparent;
    transition: all 0.3s;
}

#tocNav a:hover, #tocNav a.active {
    color: var(--accent);
    border-left-color: var(--accent);
}

.article-content {
    max-width: 800px;
}

.lead {
    font-size: 1.25rem;
    color: var(--text);
    margin-bottom: 40px;
    line-height: 1.8;
}

.article-content h2 {
    font-size: 2rem;
    margin: 50px 0 20px;
    color: #fff;
    position: relative;
    padding-bottom: 10px;
}

.article-content h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 3px;
    background: var(--gradient-1);
    border-radius: 2px;
}

.article-content h3 {
    font-size: 1.4rem;
    margin: 30px 0 15px;
    color: var(--accent);
}

.article-content p {
    margin-bottom: 20px;
    color: var(--muted);
}

.article-content a {
    color: var(--accent);
    text-decoration: none;
    border-bottom: 1px solid transparent;
    transition: border-color 0.3s;
}

.article-content a:hover {
    border-bottom-color: var(--accent);
}

.tip-card {
    background: linear-gradient(135deg, rgba(212, 175, 55, 0.1), rgba(26, 46, 37, 0.3));
    border-left: 4px solid var(--accent);
    margin: 30px 0;
}

.tip-card h4 {
    color: var(--accent);
    margin-bottom: 10px;
}

.step-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin: 30px 0;
}

.step-card {
    position: relative;
    overflow: hidden;
}

.step-number {
    font-size: 3rem;
    font-weight: 900;
    color: rgba(212, 175, 55, 0.1);
    position: absolute;
    top: 10px;
    right: 20px;
}

.step-card h4 {
    color: #fff;
    margin-bottom: 10px;
    margin-top: 10px;
}

.feature-list {
    list-style: none;
    margin: 30px 0;
}

.feature-list li {
    padding: 15px 0 15px 30px;
    position: relative;
    color: var(--muted);
    border-bottom: 1px solid var(--glass-border);
}

.feature-list li::before {
    content: '▹';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-size: 1.2rem;
}

.feature-list strong {
    color: var(--text);
}

.numbered-list {
    counter-reset: item;
    list-style: none;
    margin: 30px 0;
}

.numbered-list li {
    counter-increment: item;
    margin-bottom: 20px;
    padding-left: 50px;
    position: relative;
    color: var(--muted);
}

.numbered-list li::before {
    content: counter(item);
    position: absolute;
    left: 0;
    top: 0;
    width: 30px;
    height: 30px;
    background: var(--gradient-1);
    color: var(--primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.9rem;
}

.numbered-list strong {
    color: var(--text);
    display: block;
    margin-bottom: 5px;
}

.cta-section {
    padding: 40px 20px 100px;
}

.cta-card {
    background: linear-gradient(135deg, rgba(26, 46, 37, 0.8), rgba(10, 15, 13, 0.9));
    text-align: center;
    padding: 60px 40px;
    border: 1px solid rgba(212, 175, 55, 0.2);
}

.cta-content h2 {
    font-size: 2.5rem;
    margin-bottom: 15px;
    color: #fff;
}

.cta-content p {
    color: var(--muted);
    margin-bottom: 40px;
    font-size: 1.1rem;
}

.contact-details {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 20px;
    margin-bottom: 40px;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text);
    text-decoration: none;
    padding: 12px 20px;
    background: rgba(255, 255, 255, 0.03);
    border-radius: 8px;
    border: 1px solid var(--glass-border);
    transition: all 0.3s;
}

.contact-item:hover {
    background: var(--surface-hover);
    border-color: var(--accent);
    transform: translateY(-3px);
    color: var(--accent);
}

.btn-large {
    padding: 16px 40px;
    font-size: 1.1rem;
}

.glass-footer {
    background: rgba(5, 8, 7, 0.95);
    border-top: 1px solid var(--glass-border);
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
}

.footer-brand p {
    color: var(--muted);
    font-size: 0.9rem;
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-links a {
    color: var(--muted);
    text-decoration: none;
    transition: color 0.3s;
}

.footer-links a:hover {
    color: var(--accent);
}

.footer-social {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.footer-social > span {
    color: var(--muted);
    font-size: 0.9rem;
}

.social-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--surface);
    border: 1px solid var(--glass-border);
    border-radius: 8px;
    color: var(--text);
    transition: all 0.3s;
}

.social-icon:hover {
    background: var(--accent);
    color: var(--primary);
    transform: translateY(-3px) scale(1.1);
    box-shadow: 0 0 20px var(--accent-glow);
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid var(--glass-border);
    color: var(--muted);
    font-size: 0.85rem;
}

.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--gradient-1);
    border: none;
    border-radius: 50%;
    color: var(--primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s;
    z-index: 999;
    box-shadow: 0 5px 15px rgba(212, 175, 55, 0.3);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-5px);
}

.reveal-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s ease;
}

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

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
    .reveal-on-scroll {
        opacity: 1;
        transform: none;
    }
}

@media (max-width: 968px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-text h1 {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        margin: 0 auto 30px;
    }
    
    .hero-cta-group {
        justify-content: center;
    }
    
    .hero-visual {
        width: 300px;
        height: 300px;
        margin: 0 auto;
    }
    
    .layout-grid {
        grid-template-columns: 1fr;
    }
    
    .toc-sidebar {
        position: relative;
        top: 0;
        order: -1;
    }
    
    .desktop-nav {
        display: none;
    }
    
    .mobile-menu-btn {
        display: flex;
    }
}

@media (max-width: 600px) {
    .hero-text h1 {
        font-size: 2rem;
    }
    
    .contact-details {
        flex-direction: column;
        align-items: center;
    }
    
    .step-cards {
        grid-template-columns: 1fr;
    }
}