@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Outfit:wght@400;500;600;700;800&display=swap');

:root {
    --bg-main: #0b0c10;
    --bg-card: rgba(255, 255, 255, 0.03);
    --bg-card-hover: rgba(255, 255, 255, 0.06);
    --border-color: rgba(255, 255, 255, 0.08);
    --border-color-hover: rgba(255, 255, 255, 0.15);
    
    --primary: #818cf8; /* indigo */
    --primary-gradient: linear-gradient(135deg, #6366f1 0%, #a855f7 100%);
    --primary-hover-gradient: linear-gradient(135deg, #4f46e5 0%, #9333ea 100%);
    --secondary-gradient: linear-gradient(135deg, rgba(255, 255, 255, 0.05) 0%, rgba(255, 255, 255, 0.01) 100%);
    
    --text-primary: #f3f4f6;
    --text-secondary: #9ca3af;
    --text-muted: #6b7280;
    --accent: #c084fc;
    
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --font-heading: 'Outfit', sans-serif;
    --font-body: 'Inter', sans-serif;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    scrollbar-width: thin;
    scrollbar-color: var(--border-color) var(--bg-main);
}

body {
    background-color: var(--bg-main);
    color: var(--text-primary);
    font-family: var(--font-body);
    line-height: 1.6;
    overflow-x: hidden;
    position: relative;
}

/* Background Gradients */
body::before {
    content: '';
    position: absolute;
    width: 600px;
    height: 600px;
    top: -200px;
    left: -100px;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.15) 0%, rgba(0, 0, 0, 0) 70%);
    z-index: -1;
    pointer-events: none;
}

body::after {
    content: '';
    position: absolute;
    width: 800px;
    height: 800px;
    bottom: 20%;
    right: -200px;
    background: radial-gradient(circle, rgba(168, 85, 247, 0.1) 0%, rgba(0, 0, 0, 0) 70%);
    z-index: -1;
    pointer-events: none;
}

a {
    color: inherit;
    text-decoration: none;
    transition: var(--transition);
}

/* Header & Navbar */
header {
    background: rgba(11, 12, 16, 0.7);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.logo img {
    height: 40px;
    width: 40px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid var(--border-color);
}

.nav-menu {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    font-size: 0.95rem;
    color: var(--text-secondary);
    font-weight: 500;
}

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

.nav-btn {
    padding: 0.6rem 1.2rem;
    border-radius: 8px;
    font-weight: 600;
    font-size: 0.9rem;
    border: 1px solid var(--border-color);
    background: rgba(255, 255, 255, 0.05);
}

.nav-btn:hover {
    background: var(--primary-gradient);
    border-color: transparent;
    box-shadow: 0 0 15px rgba(99, 102, 241, 0.4);
}

/* Hero Section */
.hero {
    padding: 9rem 2rem 6rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
    text-align: center;
    position: relative;
}

.hero-badge {
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.2);
    color: var(--primary);
    padding: 0.5rem 1.2rem;
    border-radius: 50px;
    font-size: 0.85rem;
    font-weight: 600;
    display: inline-block;
    margin-bottom: 2rem;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.hero h1 {
    font-family: var(--font-heading);
    font-size: 3.5rem;
    line-height: 1.2;
    font-weight: 800;
    margin-bottom: 1.5rem;
    background: linear-gradient(to right, #ffffff, #a5b4fc, #e9d5ff);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero p {
    font-size: 1.2rem;
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto 2.5rem auto;
}

.hero-btns {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.btn-primary {
    background: var(--primary-gradient);
    color: white;
    padding: 0.85rem 2rem;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1.05rem;
    border: none;
    box-shadow: 0 4px 20px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
    background: var(--primary-hover-gradient);
    box-shadow: 0 4px 25px rgba(99, 102, 241, 0.5);
    transform: translateY(-2px);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 0.85rem 2rem;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1.05rem;
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--border-color-hover);
    transform: translateY(-2px);
}

/* Features Grid */
.section-title {
    font-family: var(--font-heading);
    font-size: 2.2rem;
    text-align: center;
    margin-bottom: 1rem;
    font-weight: 700;
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 3rem auto;
    font-size: 1rem;
}

.features {
    padding: 5rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 2.5rem 2rem;
    border-radius: 16px;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.05) 0%, rgba(168, 85, 247, 0.05) 100%);
    opacity: 0;
    transition: var(--transition);
    z-index: 0;
}

.feature-card:hover::before {
    opacity: 1;
}

.feature-card:hover {
    border-color: var(--border-color-hover);
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
    position: relative;
    z-index: 1;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    display: inline-block;
}

.feature-card h3 {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    position: relative;
    z-index: 1;
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    position: relative;
    z-index: 1;
}

/* Pricing Section */
.pricing {
    padding: 5rem 2rem;
    background: rgba(255, 255, 255, 0.01);
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
}

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

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    align-items: stretch;
}

.pricing-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 3rem 2rem;
    text-align: center;
    position: relative;
    transition: var(--transition);
    display: flex;
    flex-direction: column;
}

.pricing-card.popular {
    border: 2px solid var(--primary);
    background: rgba(99, 102, 241, 0.03);
    transform: scale(1.02);
}

.pricing-card.popular::after {
    content: '推荐';
    position: absolute;
    top: 1.2rem;
    right: 1.2rem;
    background: var(--primary-gradient);
    color: white;
    font-size: 0.75rem;
    font-weight: 700;
    padding: 0.25rem 0.75rem;
    border-radius: 50px;
}

.pricing-card:hover {
    border-color: var(--border-color-hover);
    transform: translateY(-5px);
}

.pricing-card.popular:hover {
    border-color: var(--primary);
    transform: translateY(-5px) scale(1.02);
}

.pricing-name {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

.pricing-price {
    font-family: var(--font-heading);
    font-size: 3rem;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    display: flex;
    justify-content: center;
    align-items: baseline;
}

.pricing-price span {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-left: 0.25rem;
}

.pricing-features {
    list-style: none;
    margin-bottom: 2.5rem;
    text-align: left;
    flex-grow: 1;
}

.pricing-features li {
    padding: 0.6rem 0;
    font-size: 0.95rem;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.pricing-features li::before {
    content: '✓';
    color: var(--primary);
    font-weight: 800;
}

/* Articles/Blog Section */
.articles-section {
    padding: 5rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.articles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
}

.article-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    overflow: hidden;
    transition: var(--transition);
    display: flex;
    flex-direction: column;
}

.article-card:hover {
    border-color: var(--border-color-hover);
    transform: translateY(-5px);
}

.article-body {
    padding: 2rem;
    display: flex;
    flex-direction: column;
    height: 100%;
}

.article-meta {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: 0.75rem;
    display: flex;
    gap: 1rem;
}

.article-title {
    font-family: var(--font-heading);
    font-size: 1.2rem;
    font-weight: 600;
    line-height: 1.4;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

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

.article-excerpt {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 1.5rem;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
    flex-grow: 1;
}

.article-link {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--primary);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

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

.article-link::after {
    content: '→';
    transition: var(--transition);
}

.article-link:hover::after {
    transform: translateX(5px);
}

/* User Reviews Section */
.reviews {
    padding: 5rem 2rem;
    background: rgba(255, 255, 255, 0.01);
    border-top: 1px solid var(--border-color);
}

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

.reviews-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.review-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 2.5rem 2rem;
    border-radius: 16px;
    transition: var(--transition);
}

.review-card:hover {
    border-color: var(--border-color-hover);
}

.review-rating {
    color: #fbbf24;
    font-size: 1.1rem;
    margin-bottom: 1rem;
}

.review-text {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    font-style: italic;
}

.review-user {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.user-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--primary-gradient);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.9rem;
    color: white;
}

.user-info h4 {
    font-family: var(--font-heading);
    font-size: 0.95rem;
    font-weight: 600;
}

.user-info p {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* FAQ Section */
.faq {
    padding: 5rem 2rem;
    max-width: 800px;
    margin: 0 auto;
}

.faq-list {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

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

.faq-item:hover {
    border-color: var(--border-color-hover);
}

.faq-question {
    padding: 1.5rem;
    font-family: var(--font-heading);
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.faq-question::after {
    content: '+';
    font-size: 1.5rem;
    font-weight: 300;
    transition: var(--transition);
}

.faq-item.active .faq-question::after {
    transform: rotate(45deg);
}

.faq-answer {
    padding: 0 1.5rem;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out, padding 0.3s ease-out;
    color: var(--text-secondary);
    font-size: 0.95rem;
    border-top: 1px solid transparent;
}

.faq-item.active .faq-answer {
    padding: 1.2rem 1.5rem;
    max-height: 250px;
    border-top: 1px solid var(--border-color);
}

/* Call to Action Section */
.cta {
    padding: 6rem 2rem;
    text-align: center;
    max-width: 900px;
    margin: 0 auto;
}

.cta h2 {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    background: linear-gradient(to right, #ffffff, #a5b4fc);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.cta p {
    color: var(--text-secondary);
    font-size: 1.1rem;
    max-width: 600px;
    margin: 0 auto 2.5rem auto;
}

/* Footer & PBN Weight Pipe Links */
footer {
    border-top: 1px solid var(--border-color);
    padding: 4rem 2rem;
    background: rgba(11, 12, 16, 0.95);
    text-align: center;
    font-size: 0.9rem;
    color: var(--text-muted);
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2rem;
}

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

.footer-links {
    display: flex;
    gap: 2rem;
    flex-wrap: wrap;
    justify-content: center;
}

.footer-links a {
    color: var(--text-secondary);
}

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

/* PBN Weight Pipe Container */
.pbn-pipe-links {
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px dashed rgba(255, 255, 255, 0.05);
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1.5rem;
    font-size: 0.8rem;
    letter-spacing: 0.02em;
}

.pbn-pipe-links a {
    color: var(--text-muted);
    font-weight: 500;
    transition: var(--transition);
}

.pbn-pipe-links a:hover {
    color: var(--primary);
    text-decoration: underline;
}

.copyright {
    font-size: 0.8rem;
}

/* Article Template Specific Styles */
.article-page {
    padding-top: 8rem;
    max-width: 800px;
    margin: 0 auto 5rem auto;
    padding-left: 1.5rem;
    padding-right: 1.5rem;
}

.article-header {
    margin-bottom: 3rem;
}

.article-header h1 {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    font-weight: 800;
    line-height: 1.25;
    margin-bottom: 1.5rem;
    background: linear-gradient(to right, #ffffff, #c084fc, #818cf8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.article-content {
    font-size: 1.1rem;
    color: #d1d5db;
    line-height: 1.8;
}

.article-content p {
    margin-bottom: 1.5rem;
}

.article-content h2 {
    font-family: var(--font-heading);
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--text-primary);
    margin: 2.5rem 0 1.2rem 0;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--border-color);
}

.article-content h3 {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin: 2rem 0 1rem 0;
}

.article-content ul, .article-content ol {
    margin-bottom: 1.5rem;
    padding-left: 2rem;
}

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

.article-inner-links {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    padding: 1.5rem;
    border-radius: 12px;
    margin: 3rem 0;
}

.article-inner-links h4 {
    font-family: var(--font-heading);
    font-weight: 600;
    margin-bottom: 1rem;
    font-size: 1rem;
    color: var(--primary);
}

.article-inner-links ul {
    list-style: none;
    padding-left: 0;
    margin-bottom: 0;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.article-inner-links a {
    font-size: 0.95rem;
    color: var(--text-secondary);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.article-inner-links a:hover {
    color: var(--primary);
}

.article-cta-box {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1) 0%, rgba(168, 85, 247, 0.1) 100%);
    border: 1px solid rgba(99, 102, 241, 0.2);
    padding: 2.5rem;
    border-radius: 16px;
    text-align: center;
    margin: 3rem 0;
}

.article-cta-box h3 {
    margin-top: 0;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
}

.article-cta-box p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 1.5rem;
}

.back-to-home {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
    font-weight: 500;
    margin-bottom: 2rem;
}

.back-to-home:hover {
    color: var(--text-primary);
}

/* Mobile responsive menu */
@media (max-width: 768px) {
    .nav-container {
        padding: 1rem;
    }
    
    .nav-menu {
        display: none;
    }
    
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .hero p {
        font-size: 1rem;
    }
    
    .section-title {
        font-size: 1.8rem;
    }
    
    .pricing-card.popular {
        transform: scale(1);
    }
    
    .pricing-card.popular:hover {
        transform: translateY(-5px);
    }
}