:root {
    --bg-dark: #020617;
    --bg-card: rgba(15, 23, 42, 0.55);
    --border-glass: rgba(255, 255, 255, 0.08);
    --border-glow: rgba(59, 130, 246, 0.3);
    
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    
    --color-primary: #3b82f6;      /* Blue */
    --color-secondary: #10b981;    /* Emerald */
    --color-gold: #f59e0b;         /* Gold */
    --color-cyan: #06b6d4;         /* Cyan */
    --color-magenta: #d946ef;      /* Magenta */
    
    --font-outfit: 'Outfit', sans-serif;
    --font-inter: 'Inter', sans-serif;
}

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

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

body {
    background-color: var(--bg-dark);
    color: var(--text-primary);
    font-family: var(--font-inter);
    line-height: 1.6;
    overflow-x: hidden;
    position: relative;
    min-height: 100vh;
}

/* Language Display System */
html[lang="ko"] .lang-en {
    display: none !important;
}
html[lang="ko"] .lang-ko {
    display: inline;
}
html[lang="en"] .lang-ko {
    display: none !important;
}
html[lang="en"] .lang-en {
    display: inline;
}

/* Background Aesthetics */
.stars-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background-image: 
        radial-gradient(1px 1px at 20px 30px, #eee, rgba(0,0,0,0)),
        radial-gradient(1px 1px at 40px 70px, #fff, rgba(0,0,0,0)),
        radial-gradient(2px 2px at 90px 110px, #ddd, rgba(0,0,0,0)),
        radial-gradient(1px 1px at 150px 175px, #fff, rgba(0,0,0,0));
    background-repeat: repeat;
    background-size: 200px 200px;
    opacity: 0.15;
    z-index: -3;
    pointer-events: none;
}

.glow-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(120px);
    opacity: 0.25;
    z-index: -2;
    pointer-events: none;
    animation: float 20s infinite alternate;
}

.orb-1 {
    top: -100px;
    right: -100px;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, var(--color-cyan) 0%, rgba(0,0,0,0) 70%);
}

.orb-2 {
    top: 40%;
    left: -200px;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, var(--color-magenta) 0%, rgba(0,0,0,0) 70%);
    animation-delay: -10s;
}

@keyframes float {
    0% { transform: translateY(0) scale(1); }
    100% { transform: translateY(50px) scale(1.1); }
}

/* Header styling */
header {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo-icon {
    font-size: 1.8rem;
    filter: drop-shadow(0 0 10px var(--color-cyan));
}

.logo-text {
    font-family: var(--font-outfit);
    font-weight: 800;
    font-size: 1.5rem;
    letter-spacing: 2px;
    background: linear-gradient(135deg, #fff 0%, var(--text-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.8rem 1.8rem;
    font-family: var(--font-outfit);
    font-weight: 600;
    font-size: 0.95rem;
    border-radius: 50px;
    border: none;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    text-decoration: none;
    text-align: center;
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-cyan) 100%);
    color: #fff;
    box-shadow: 0 4px 20px rgba(6, 182, 212, 0.35);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 24px rgba(6, 182, 212, 0.5);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
    border: 1px solid var(--border-glass);
    backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

/* Main Layout */
main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Hero Section */
.hero-section {
    padding: 8rem 0;
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.hero-badge {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-glass);
    padding: 0.5rem 1.2rem;
    border-radius: 100px;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--color-cyan);
    margin-bottom: 2rem;
    letter-spacing: 1px;
    text-transform: uppercase;
    backdrop-filter: blur(8px);
}

.hero-title {
    font-family: var(--font-outfit);
    font-size: clamp(3rem, 7vw, 5rem);
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    letter-spacing: -2px;
}

.gradient-text {
    background: linear-gradient(135deg, #fff 20%, var(--color-cyan) 60%, var(--color-magenta) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    filter: drop-shadow(0 0 30px rgba(6, 182, 212, 0.15));
}

.hero-subtitle {
    font-size: clamp(1.1rem, 2vw, 1.4rem);
    color: var(--text-secondary);
    max-width: 700px;
    margin-bottom: 3rem;
    font-weight: 300;
}

.hero-actions {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* Section titles */
.section-title {
    font-family: var(--font-outfit);
    font-size: clamp(2.2rem, 4vw, 3rem);
    font-weight: 800;
    text-align: center;
    margin-bottom: 1rem;
    letter-spacing: -1px;
}

.section-description {
    text-align: center;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 4rem auto;
    font-size: 1.1rem;
    font-weight: 300;
}

/* Ecosystem Section & Grid */
.ecosystem-section {
    padding: 6rem 0;
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.ecosystem-card {
    background: var(--bg-card);
    border: 1px solid var(--border-glass);
    padding: 2.5rem;
    border-radius: 20px;
    backdrop-filter: blur(12px);
    transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    position: relative;
    overflow: hidden;
}

.ecosystem-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: linear-gradient(90deg, transparent, var(--color-primary), transparent);
    opacity: 0;
    transition: opacity 0.4s ease;
}

.ecosystem-card:hover {
    transform: translateY(-5px);
    border-color: rgba(255, 255, 255, 0.15);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.ecosystem-card:hover::before {
    opacity: 1;
}

.ecosystem-card.highlight {
    background: rgba(30, 41, 59, 0.5);
    border-color: var(--border-glow);
}

.ecosystem-card.highlight::before {
    background: linear-gradient(90deg, transparent, var(--color-gold), transparent);
}

.card-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.2rem;
}

.card-icon {
    font-size: 2rem;
}

.ecosystem-card h3 {
    font-family: var(--font-outfit);
    font-weight: 700;
    font-size: 1.3rem;
    color: #fff;
}

.card-text {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
    font-weight: 300;
}

/* Interactive Economy Loop Section */
.economy-section {
    padding: 6rem 0;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.loop-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1.5rem;
    margin-bottom: 5rem;
    flex-wrap: wrap;
}

.loop-step {
    flex: 1;
    min-width: 250px;
    background: var(--bg-card);
    border: 1px solid var(--border-glass);
    padding: 2.5rem;
    border-radius: 20px;
    backdrop-filter: blur(12px);
    position: relative;
    transition: all 0.3s ease;
}

.loop-step:hover {
    border-color: var(--color-cyan);
    box-shadow: 0 0 25px rgba(6, 182, 212, 0.15);
}

.step-num {
    font-family: var(--font-outfit);
    font-size: 3rem;
    font-weight: 800;
    color: rgba(6, 182, 212, 0.2);
    position: absolute;
    top: 10px;
    right: 20px;
}

.loop-step h4 {
    font-family: var(--font-outfit);
    font-size: 1.2rem;
    margin-bottom: 1rem;
    color: #fff;
    font-weight: 700;
}

.loop-step p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 300;
    line-height: 1.5;
}

.loop-arrow {
    font-size: 1.5rem;
    color: var(--color-cyan);
}

@media (max-width: 768px) {
    .loop-container {
        flex-direction: column;
    }
    .loop-arrow {
        transform: rotate(90deg);
        margin: 0.5rem 0;
    }
}

/* Simulator Card */
.simulator-card {
    max-width: 600px;
    margin: 0 auto;
    background: linear-gradient(135deg, rgba(30, 41, 59, 0.6) 0%, rgba(15, 23, 42, 0.8) 100%);
    border: 1px solid rgba(255, 255, 255, 0.08);
    padding: 3rem;
    border-radius: 24px;
    backdrop-filter: blur(16px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.4);
}

.simulator-card h3 {
    font-family: var(--font-outfit);
    font-size: 1.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 2rem;
}

.sim-controls {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.sim-group {
    flex: 1;
    min-width: 200px;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.sim-group label {
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-weight: 500;
    letter-spacing: 0.5px;
}

.sim-group select, .sim-group input {
    background: rgba(15, 23, 42, 0.7);
    border: 1px solid var(--border-glass);
    padding: 0.8rem 1rem;
    border-radius: 12px;
    color: #fff;
    font-family: var(--font-inter);
    outline: none;
    font-size: 0.95rem;
    transition: all 0.3s ease;
}

.sim-group select:focus, .sim-group input:focus {
    border-color: var(--color-cyan);
    box-shadow: 0 0 10px rgba(6, 182, 212, 0.2);
}

#sim-btn {
    width: 100%;
    margin-bottom: 2rem;
}

.sim-result {
    text-align: center;
    font-size: 1.1rem;
    color: var(--text-secondary);
}

.sim-result strong {
    font-family: var(--font-outfit);
    font-size: 2rem;
    color: var(--color-gold);
    text-shadow: 0 0 15px rgba(245, 158, 11, 0.3);
    margin: 0 0.3rem;
}

/* Footer */
footer {
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    padding: 4rem 2rem;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-top: 6rem;
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

.footer-note {
    font-size: 0.8rem;
    opacity: 0.7;
    font-weight: 300;
}