/* Layout CSS - Page layout and sections */

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 4rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--text-primary);
}

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

.nav {
    display: flex;
    align-items: center;
    gap: var(--space-8);
}

.nav-link {
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
    position: relative;
}

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

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    right: 0;
    height: 2px;
    background-color: var(--color-primary);
    border-radius: var(--radius-full);
}

/* Hero Section */
.hero {
    padding-top: 8rem;
    padding-bottom: var(--space-20);
    background: linear-gradient(180deg, #f8fafc 0%, #ffffff 100%);
}

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

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-6);
    line-height: 1.2;
}

.hero-title .highlight {
    background: linear-gradient(135deg, #2563eb 0%, #3b82f6 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-desc {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-10);
    line-height: 1.7;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: var(--space-12);
    margin-bottom: var(--space-10);
}

.stat-item {
    text-align: center;
}

.stat-num {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-primary);
    line-height: 1;
}

.stat-label {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    margin-top: var(--space-2);
}

.hero-actions {
    display: flex;
    justify-content: center;
    gap: var(--space-4);
}

/* Filter Section */
.filter-section {
    padding: var(--space-16) 0 var(--space-8);
    background-color: var(--bg-primary);
}

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

.section-subtitle {
    font-size: 1rem;
    color: var(--text-secondary);
    text-align: center;
    margin-bottom: var(--space-8);
}

.filter-header {
    margin-bottom: var(--space-8);
}

.filter-bar {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
}

.filter-categories {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-3);
    justify-content: center;
}

.filter-search {
    position: relative;
    max-width: 400px;
    margin: 0 auto;
    width: 100%;
}

.search-btn {
    position: absolute;
    right: var(--space-3);
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
    padding: var(--space-2);
}

.search-btn:hover {
    color: var(--color-primary);
}

/* Sites Section */
.sites-section {
    padding: var(--space-8) 0 var(--space-20);
    background-color: var(--bg-primary);
}

.sites-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--space-6);
}

/* Features Section */
.features-section {
    padding: var(--space-20) 0;
    background-color: var(--bg-secondary);
}

.features-section .section-title {
    margin-bottom: var(--space-12);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: var(--space-6);
}

/* About Section */
.about-section {
    padding: var(--space-20) 0;
    background-color: var(--bg-primary);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-16);
    align-items: start;
}

.about-text .section-title {
    text-align: left;
    margin-bottom: var(--space-6);
}

.about-text p {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: var(--space-4);
}

.about-notice {
    margin-top: var(--space-6);
    background-color: #fef3c7;
    border-left: 4px solid #f59e0b;
    padding: var(--space-4) var(--space-5);
    border-radius: var(--radius-md);
    font-size: 0.9375rem;
    color: #92400e;
}

.about-faq h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--space-6);
}

/* Footer */
.footer {
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: var(--space-16) 0 var(--space-8);
}

.footer-inner {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: var(--space-12);
    margin-bottom: var(--space-12);
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--text-primary);
    margin-bottom: var(--space-4);
}

.footer-desc {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.footer-col h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--space-4);
}

.footer-col a {
    display: block;
    font-size: 0.9375rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-3);
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--space-8);
    border-top: 1px solid var(--border-color);
}

.footer-bottom p {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-bottom: 0;
}

.update-time {
    color: var(--text-secondary);
}

/* Responsive Design */
@media (max-width: 1024px) {
    .about-content {
        grid-template-columns: 1fr;
        gap: var(--space-12);
    }
    
    .footer-inner {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    :root {
        --container-padding: 1rem;
    }
    
    .hero {
        padding-top: 6rem;
        padding-bottom: var(--space-16);
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-stats {
        gap: var(--space-8);
    }
    
    .stat-num {
        font-size: 2rem;
    }
    
    .hero-actions {
        flex-direction: column;
        align-items: center;
    }
    
    .nav {
        display: none;
    }
    
    .sites-grid {
        grid-template-columns: 1fr;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-inner {
        grid-template-columns: 1fr;
        gap: var(--space-8);
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: var(--space-3);
        text-align: center;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 1.75rem;
    }
    
    .hero-desc {
        font-size: 1rem;
    }
    
    .section-title {
        font-size: 1.5rem;
    }
    
    .filter-categories {
        justify-content: flex-start;
        overflow-x: auto;
        flex-wrap: nowrap;
        padding-bottom: var(--space-2);
    }
}