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

:root {
    --primary-color: #007AFF;
    --primary-dark: #0056b3;
    --secondary-color: #5856D6;
    --success-color: #34C759;
    --warning-color: #FF9500;
    --danger-color: #FF3B30;
    --text-color: #1D1D1F;
    --text-secondary: #86868B;
    --background: #FFFFFF;
    --background-alt: #F5F5F7;
    --border-color: #E5E5E7;
    --card-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background: var(--background);
}

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

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 60px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-color);
    text-decoration: none;
}

.logo-icon {
    width: 32px;
    height: 32px;
    border-radius: 6px;
    object-fit: cover;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 32px;
}

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

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

.nav-lang {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.875rem;
}

.nav-lang a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    padding: 4px 8px;
    border-radius: 4px;
    transition: all 0.2s;
}

.nav-lang a.active {
    color: var(--primary-color);
    background: rgba(0, 122, 255, 0.1);
}

.nav-lang span {
    color: var(--border-color);
}

/* Hero Section */
.hero {
    padding: 140px 20px 80px;
    text-align: center;
    background: linear-gradient(180deg, var(--background-alt) 0%, var(--background) 100%);
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero-icon {
    width: 180px;
    height: 180px;
    border-radius: 32px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.15);
    margin-bottom: 24px;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 16px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.5rem;
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.hero-description {
    font-size: 1.125rem;
    color: var(--text-color);
    margin-bottom: 32px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-badges {
    display: flex;
    justify-content: center;
    gap: 12px;
    flex-wrap: wrap;
}

.badge {
    display: inline-block;
    padding: 8px 16px;
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
}

/* Sections */
.section {
    padding: 80px 20px;
}

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

.section h2 {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 48px;
}

/* Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.feature-card {
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 32px;
    transition: transform 0.2s, box-shadow 0.2s;
}

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

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 8px;
}

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

/* Guide Section */
.guide-content {
    display: grid;
    gap: 32px;
}

.guide-article {
    background: var(--background);
    border-radius: 16px;
    padding: 32px;
    box-shadow: var(--card-shadow);
}

.guide-article h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 16px;
}

.guide-article ol,
.guide-article ul {
    margin-left: 24px;
}

.guide-article li {
    margin-bottom: 8px;
}

.guide-article a {
    color: var(--primary-color);
}

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

.faq-item {
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    margin-bottom: 12px;
    overflow: hidden;
}

.faq-item summary {
    padding: 20px 24px;
    font-weight: 600;
    cursor: pointer;
    list-style: none;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.faq-item summary::-webkit-details-marker {
    display: none;
}

.faq-item summary::after {
    content: '+';
    font-size: 1.5rem;
    color: var(--text-secondary);
    transition: transform 0.2s;
}

.faq-item[open] summary::after {
    transform: rotate(45deg);
}

.faq-item p {
    padding: 0 24px 20px;
    color: var(--text-secondary);
}

/* Footer */
.footer {
    padding: 40px 20px;
    text-align: center;
    background: var(--text-color);
    color: var(--background);
}

.footer p {
    margin-bottom: 8px;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
}

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

/* Responsive */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }

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

    .hero-subtitle {
        font-size: 1.25rem;
    }

    .section h2 {
        font-size: 2rem;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }
}