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

:root {
    /* Colors */
    --color-primary: #2563eb;
    --color-primary-dark: #1d4ed8;
    --color-secondary: #64748b;
    --color-text: #1e293b;
    --color-text-light: #64748b;
    --color-bg: #ffffff;
    --color-bg-alt: #f8fafc;
    --color-border: #e2e8f0;
    --color-success: #10b981;
    --color-error: #ef4444;

    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    --font-size-4xl: 2.5rem;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;

    /* Layout */
    --container-max-width: 1200px;
    --header-height: 64px;
    --border-radius: 0.5rem;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-bg);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ===================================
   Container
   =================================== */
.container {
    width: 100%;
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ===================================
   Header & Navigation
   =================================== */
.header {
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav {
    height: var(--header-height);
    display: flex;
    align-items: center;
}

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

.logo {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--color-primary);
    text-decoration: none;
}

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

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

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

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--color-text);
    transition: all 0.3s;
}

/* ===================================
   Main Content
   =================================== */
.main {
    flex: 1;
    padding: var(--spacing-2xl) 0;
}

/* ===================================
   Hero Section
   =================================== */
.hero {
    text-align: center;
    padding: var(--spacing-2xl) 0;
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
}

.hero h1 {
    font-size: var(--font-size-4xl);
    font-weight: 800;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
}

.hero-description {
    font-size: var(--font-size-lg);
    color: var(--color-text-light);
    max-width: 700px;
    margin: 0 auto var(--spacing-lg);
}

.cta-buttons {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    margin-bottom: var(--spacing-2xl);
}

.btn {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-xl);
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 600;
    transition: all 0.2s;
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    background: var(--color-primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

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

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

.btn-outline {
    background: transparent;
    color: var(--color-primary);
    border: 2px solid var(--color-primary);
}

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

.btn-large {
    padding: var(--spacing-md) var(--spacing-2xl);
    font-size: var(--font-size-lg);
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: var(--spacing-2xl);
}

.stat {
    text-align: center;
}

.stat strong {
    display: block;
    font-size: var(--font-size-3xl);
    font-weight: 800;
    color: var(--color-primary);
}

.stat span {
    color: var(--color-text-light);
    font-size: var(--font-size-sm);
}

/* ===================================
   Sections
   =================================== */
.section {
    padding: var(--spacing-2xl) 0;
}

.section-alt {
    background: var(--color-bg-alt);
}

.section-title {
    text-align: center;
    font-size: var(--font-size-3xl);
    font-weight: 700;
    margin-bottom: var(--spacing-2xl);
    color: var(--color-primary);
}

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

.feature-card {
    background: var(--color-bg);
    padding: var(--spacing-xl);
    border-radius: var(--border-radius);
    border: 1px solid var(--color-border);
    transition: all 0.3s;
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
}

.feature-card h3 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.feature-card p {
    color: var(--color-text-light);
}

/* ===================================
   Korean Features
   =================================== */
.korean-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.korean-feature {
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    border-left: 4px solid var(--color-primary);
}

.korean-feature h3 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

/* ===================================
   Comparison Table
   =================================== */
.comparison-table {
    overflow-x: auto;
}

.comparison-table table {
    width: 100%;
    border-collapse: collapse;
    background: white;
}

.comparison-table th,
.comparison-table td {
    padding: var(--spacing-md);
    text-align: center;
    border: 1px solid var(--color-border);
}

.comparison-table th {
    background: var(--color-bg-alt);
    font-weight: 600;
}

.comparison-table .highlight {
    background: #dbeafe;
    font-weight: 600;
}

/* ===================================
   FAQ
   =================================== */
.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: white;
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    border-radius: var(--border-radius);
    border: 1px solid var(--color-border);
}

.faq-item h3 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

/* ===================================
   CTA Section
   =================================== */
.cta-section {
    text-align: center;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    color: white;
    padding: var(--spacing-2xl) 0;
}

.cta-section h2 {
    font-size: var(--font-size-3xl);
    margin-bottom: var(--spacing-md);
}

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

.cta-section .btn-primary:hover {
    background: var(--color-bg-alt);
}

/* ===================================
   Page Section
   =================================== */
.page-section {
    max-width: 800px;
    margin: 0 auto;
}

.page-section h1 {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    margin-bottom: var(--spacing-xl);
    color: var(--color-primary);
}

.legal-page h1 {
    font-size: var(--font-size-2xl);
}

.update-date {
    color: var(--color-text-light);
    font-size: var(--font-size-sm);
    margin-bottom: var(--spacing-xl);
}

/* ===================================
   Content Block
   =================================== */
.content-block {
    margin-bottom: var(--spacing-xl);
}

.content-block h2 {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--color-text);
}

.content-block h3 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text);
}

.content-block p {
    margin-bottom: var(--spacing-md);
    color: var(--color-text-light);
}

.content-block ul,
.content-block ol {
    margin-left: var(--spacing-xl);
    margin-bottom: var(--spacing-md);
}

.content-block li {
    margin-bottom: var(--spacing-sm);
    color: var(--color-text-light);
}

/* ===================================
   Comparison Cards
   =================================== */
.comparison-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
}

.comparison-card {
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    border: 1px solid var(--color-border);
}

.comparison-card h3 {
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

/* ===================================
   Contact Info
   =================================== */
.contact-info {
    display: grid;
    gap: var(--spacing-lg);
}

.contact-item h3 {
    font-size: var(--font-size-base);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.contact-item a {
    color: var(--color-primary);
    text-decoration: none;
}

.contact-item a:hover {
    text-decoration: underline;
}

/* ===================================
   Ad Container
   =================================== */
.ad-container {
    margin: var(--spacing-2xl) auto;
    padding: var(--spacing-md);
    background: var(--color-bg-alt);
    border-radius: var(--border-radius);
    text-align: center;
    min-height: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-light);
}

/* ===================================
   Footer
   =================================== */
.footer {
    background: var(--color-bg-alt);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-2xl) 0 var(--spacing-md);
}

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

.footer-section h3,
.footer-section h4 {
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.footer-section ul {
    list-style: none;
}

.footer-section li {
    margin-bottom: var(--spacing-sm);
}

.footer-section a {
    color: var(--color-text-light);
    text-decoration: none;
    transition: color 0.2s;
}

.footer-section a:hover {
    color: var(--color-primary);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--color-border);
    color: var(--color-text-light);
    font-size: var(--font-size-sm);
}

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 768px) {
    :root {
        --font-size-3xl: 1.75rem;
        --font-size-4xl: 2rem;
    }

    .nav-menu {
        display: none;
        position: absolute;
        top: var(--header-height);
        left: 0;
        right: 0;
        background: var(--color-bg);
        flex-direction: column;
        padding: var(--spacing-md);
        gap: var(--spacing-md);
        border-bottom: 1px solid var(--color-border);
        box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    }

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

    .nav-toggle {
        display: flex;
    }

    .hero {
        padding: var(--spacing-xl) 0;
    }

    .hero h1 {
        font-size: var(--font-size-3xl);
    }

    .cta-buttons {
        flex-direction: column;
    }

    .hero-stats {
        flex-direction: column;
        gap: var(--spacing-md);
    }

    .footer-content {
        grid-template-columns: 1fr;
    }

    .page-section {
        padding: 0 var(--spacing-md);
    }

    .comparison-table {
        font-size: var(--font-size-sm);
    }
}

/* ===================================
   Utilities
   =================================== */
.text-center {
    text-align: center;
}

.text-muted {
    color: var(--color-text-light);
}

.mt-1 { margin-top: var(--spacing-sm); }
.mt-2 { margin-top: var(--spacing-md); }
.mt-3 { margin-top: var(--spacing-lg); }
.mt-4 { margin-top: var(--spacing-xl); }

.mb-1 { margin-bottom: var(--spacing-sm); }
.mb-2 { margin-bottom: var(--spacing-md); }
.mb-3 { margin-bottom: var(--spacing-lg); }
.mb-4 { margin-bottom: var(--spacing-xl); }