/* CSS Variables */
:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f5f5f5;
    --text-primary: #1a1a1a;
    --text-secondary: #666666;
    --accent: #f97316;
    --accent-hover: #ea580c;
    --border: #e5e5e5;
    --card-bg: #ffffff;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --hero-bg: linear-gradient(135deg, var(--accent) 0%, #fb923c 100%);
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-primary: #0f0f0f;
        --bg-secondary: #1a1a1a;
        --text-primary: #f5f5f5;
        --text-secondary: #a0a0a0;
        --accent: #fbbf24;
        --border: #2a2a2a;
        --card-bg: #1a1a1a;
        --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
        --hero-bg: linear-gradient(135deg, #78350f 0%, #451a03 100%);
    }
}

/* Reset */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    transition: background-color 0.3s, color 0.3s;
}

main {
    flex: 1;
}

/* Header */
.site-header {
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    padding: 1rem 2rem;
    position: sticky;
    top: 0;
    z-index: 100;
}

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

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--accent);
    text-decoration: none;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.theme-btn {
    background: none;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 0.5rem;
    cursor: pointer;
    font-size: 1rem;
}

.lang-switcher {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.lang-link {
    padding: 0.25rem 0.5rem;
    color: var(--text-secondary);
    text-decoration: none;
    border-radius: 4px;
    font-size: 0.875rem;
}

.lang-link:hover {
    color: var(--accent);
}

.lang-link[data-active] {
    color: var(--accent);
    font-weight: 600;
}

.lang-select {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 0.4rem 0.6rem;
    font-size: 0.875rem;
    cursor: pointer;
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 4rem 2rem;
    background: var(--hero-bg);
    color: white;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.25rem;
    opacity: 0.9;
}

/* Promo Grid */
.promo-grid {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 2rem;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.promo-card {
    background-color: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.5rem;
    text-decoration: none;
    color: inherit;
    transition: transform 0.2s, box-shadow 0.2s;
}

.promo-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow);
}

.promo-card h2 {
    color: var(--accent);
    margin-bottom: 0.5rem;
}

.promo-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.card-link {
    display: inline-block;
    margin-top: 1rem;
    color: var(--accent);
    font-weight: 500;
}

/* Single Page */
.single {
    max-width: 800px;
    margin: 2rem auto;
    padding: 0 2rem;
}

.single-header {
    margin-bottom: 2rem;
}

.single-header h1 {
    font-size: 2rem;
}

.single-content {
    line-height: 1.8;
}

.single-content h2 {
    margin-top: 2rem;
    margin-bottom: 1rem;
    color: var(--accent);
}

.single-content p {
    margin-bottom: 1rem;
}

.single-content ul, .single-content ol {
    margin-bottom: 1rem;
    padding-left: 1.5rem;
}

.single-content li {
    margin-bottom: 0.5rem;
}

/* Invitation Code Highlight */
.invite-code {
    display: inline-block;
    background: linear-gradient(135deg, var(--accent), #8b5cf6);
    color: white;
    padding: 0.5rem 1.5rem;
    border-radius: 8px;
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: 2px;
    margin: 1rem 0;
}

/* Rewards Table */
.rewards-table {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0;
}

.rewards-table th, .rewards-table td {
    border: 1px solid var(--border);
    padding: 0.75rem;
    text-align: left;
}

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

.rewards-table tr:nth-child(even) {
    background-color: var(--bg-secondary);
}

/* Footer */
.site-footer {
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border);
    padding: 1.5rem 2rem;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* Responsive */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 1.75rem;
    }

    .hero p {
        font-size: 1rem;
    }

    .lang-switcher {
        gap: 0.25rem;
    }

    .lang-link {
        font-size: 0.75rem;
        padding: 0.2rem 0.4rem;
    }

    .rewards-table {
        font-size: 0.875rem;
    }
}