:root {
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --primary-light: #eef2ff;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --card-border: #e2e8f0;
    --text-primary: #0f172a;
    --text-secondary: #64748b;
    --accent: #0284c7;
    --success: #10b981;
}

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

body {
    font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, Roboto, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Navbar */
.navbar {
    background-color: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--card-border);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

.logo-icon {
    font-size: 1.5rem;
}

.nav-links {
    display: flex;
    gap: 1.5rem;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

.nav-link:hover {
    color: var(--text-primary);
}

/* Main Container */
.main-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 3rem 1.5rem;
    flex: 1;
    width: 100%;
}

/* Hero Section */
.hero-section {
    text-align: center;
    padding: 4rem 1rem 3rem;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.badge {
    background-color: #e0e7ff;
    color: #4338ca;
    border: 1px solid #c7d2fe;
    padding: 0.35rem 1rem;
    border-radius: 9999px;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    display: inline-block;
}

.hero-title {
    font-size: 2.75rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1.25rem;
    color: var(--text-primary);
}

.highlight {
    background: linear-gradient(135deg, #4f46e5 0%, #0284c7 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 650px;
    margin-bottom: 2rem;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 2rem;
}

/* Buttons */
.btn {
    padding: 0.75rem 1.75rem;
    border-radius: 0.5rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    text-decoration: none;
    transition: all 0.2s ease;
    border: none;
}

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

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(79, 70, 229, 0.35);
}

.btn-secondary {
    background-color: #ffffff;
    color: var(--text-primary);
    border: 1px solid var(--card-border);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.btn-secondary:hover {
    background-color: #f1f5f9;
    border-color: #cbd5e1;
}


/* API Status Card */
.api-status-card {
    background-color: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 0.75rem;
    padding: 1rem 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    max-width: 500px;
    width: 100%;
    margin-top: 1rem;
    text-align: left;
    transition: border-color 0.3s;
}

.status-indicator {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: #eab308;
    flex-shrink: 0;
    box-shadow: 0 0 8px rgba(234, 179, 8, 0.6);
}

.status-indicator.success {
    background-color: var(--success);
    box-shadow: 0 0 8px rgba(16, 185, 129, 0.6);
}

.status-content strong {
    font-size: 0.95rem;
    display: block;
}

.status-content p {
    font-size: 0.825rem;
    color: var(--text-secondary);
}

/* Features Section */
.section {
    padding: 3rem 0;
}

.section-header {
    text-align: center;
    margin-bottom: 2.5rem;
}

.section-header h2 {
    font-size: 1.875rem;
    margin-bottom: 0.5rem;
}

.section-header p {
    color: var(--text-secondary);
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.card {
    background-color: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 0.75rem;
    padding: 1.5rem;
    transition: transform 0.2s, border-color 0.2s, box-shadow 0.2s;
    position: relative;
    display: flex;
    flex-direction: column;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05), 0 1px 2px rgba(0, 0, 0, 0.03);
}

.card:hover {
    transform: translateY(-4px);
    border-color: #818cf8;
    box-shadow: 0 10px 20px rgba(79, 70, 229, 0.08);
}

.card-icon {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.card-title {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.card-desc {
    color: var(--text-secondary);
    font-size: 0.9rem;
    flex: 1;
    margin-bottom: 1rem;
}

.card-tag {
    align-self: flex-start;
    font-size: 0.75rem;
    padding: 0.25rem 0.6rem;
    border-radius: 0.25rem;
    background-color: #f1f5f9;
    color: var(--text-secondary);
    border: 1px solid #e2e8f0;
}

.active-tag {
    background-color: #ecfdf5;
    color: #059669;
    border-color: #a7f3d0;
    font-weight: 600;
}

.card-interactive:hover {
    border-color: #6366f1;
    box-shadow: 0 12px 24px rgba(79, 70, 229, 0.12);
    cursor: pointer;
}


/* Footer */
.footer {
    border-top: 1px solid var(--card-border);
    padding: 1.5rem;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* Language Switcher Component */
.lang-switcher {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(8px);
    border: 1px solid #e2e8f0;
    border-radius: 9999px;
    padding: 0.2rem 0.4rem;
    font-size: 0.8rem;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
    margin-left: 0.5rem;
}

.lang-btn {
    background: none;
    border: none;
    padding: 0.2rem 0.45rem;
    font-size: 0.78rem;
    font-weight: 600;
    color: #64748b;
    border-radius: 9999px;
    cursor: pointer;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.2rem;
}

.lang-btn:hover {
    color: #1e293b;
    background-color: #f1f5f9;
}

.lang-btn.active {
    background: #4f46e5;
    color: #ffffff;
    box-shadow: 0 1px 4px rgba(79, 70, 229, 0.3);
}

.lang-divider {
    color: #cbd5e1;
    font-size: 0.75rem;
    user-select: none;
}

/* Cross-Promotion Card & SEO Guide Sections */
.cross-promo-card {
    max-width: 900px;
    margin: 2.5rem auto 1.5rem;
    padding: 2rem 2.25rem;
    border-radius: 1.25rem;
    background: linear-gradient(135deg, #1e1b4b 0%, #312e81 55%, #0f172a 100%);
    color: #ffffff;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1.75rem;
    box-shadow: 0 14px 32px rgba(30, 27, 75, 0.22);
    border: 1px solid rgba(129, 140, 248, 0.35);
}

.cross-promo-content {
    flex: 1;
}

.cross-promo-badge {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    background: rgba(34, 211, 238, 0.2);
    color: #22d3ee;
    border: 1px solid rgba(34, 211, 238, 0.4);
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    margin-bottom: 0.75rem;
}

.cross-promo-title {
    font-size: 1.4rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
    color: #ffffff;
    line-height: 1.35;
}

.cross-promo-desc {
    font-size: 0.95rem;
    color: #cbd5e1;
    line-height: 1.65;
}

.cross-promo-btn {
    flex-shrink: 0;
    background: #22d3ee;
    color: #0f172a;
    font-weight: 800;
    font-size: 0.95rem;
    padding: 0.9rem 1.5rem;
    border-radius: 9999px;
    text-decoration: none;
    box-shadow: 0 0 20px rgba(34, 211, 238, 0.45);
    transition: all 0.2s ease;
    white-space: nowrap;
}

.cross-promo-btn:hover {
    background: #67e8f9;
    transform: translateY(-2px);
    box-shadow: 0 0 28px rgba(34, 211, 238, 0.75);
}

.seo-guide-section {
    max-width: 900px;
    margin: 2rem auto 3rem;
    padding: 2.25rem 2.5rem;
    background: #ffffff;
    border: 1px solid var(--card-border);
    border-radius: 1.25rem;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.04);
    line-height: 1.8;
    color: #334155;
}

.seo-guide-section h2 {
    font-size: 1.5rem;
    font-weight: 800;
    color: #0f172a;
    margin-bottom: 1rem;
}

.seo-guide-section h3 {
    font-size: 1.15rem;
    font-weight: 700;
    color: #1e293b;
    margin-top: 1.5rem;
    margin-bottom: 0.5rem;
}

.seo-guide-section p {
    font-size: 0.96rem;
    color: #475569;
    margin-bottom: 1rem;
}

.seo-faq-box {
    margin-top: 1.75rem;
    padding-top: 1.5rem;
    border-top: 1px solid #e2e8f0;
}

.seo-faq-item {
    background: #f8fafc;
    border: 1px solid #e2e8f0;
    border-radius: 0.75rem;
    padding: 1.1rem 1.25rem;
    margin-top: 0.85rem;
}

.seo-faq-item strong {
    display: block;
    color: #0f172a;
    font-size: 0.98rem;
    margin-bottom: 0.4rem;
}

.seo-faq-item p {
    margin-bottom: 0;
    font-size: 0.92rem;
    color: #475569;
}

@media (max-width: 768px) {
    .cross-promo-card {
        flex-direction: column;
        align-items: flex-start;
        padding: 1.5rem;
    }
    .cross-promo-btn {
        width: 100%;
        text-align: center;
    }
    .seo-guide-section {
        padding: 1.5rem;
    }
}