:root {
    --primary-color: #07c160; /* WeChat Green */
    --secondary-color: #2c3e50;
    --accent-color: #3498db;
    --text-color: #333;
    --light-bg: #f8f9fa;
    --white: #ffffff;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --card-shadow: 0 10px 20px rgba(0,0,0,0.05);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

body {
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--light-bg);
    scroll-behavior: smooth;
}

img {
    max-width: 100%;
    height: auto;
}

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

/* Header */
header {
    background-color: var(--white);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--secondary-color);
}

.logo img {
    height: 40px;
    margin-right: 10px;
}

.nav-links {
    display: flex;
    gap: 20px;
    align-items: center;
}

.nav-links a:not(.btn):not(.dropdown-toggle) {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s;
}

.nav-links a:not(.btn):not(.dropdown-toggle):hover {
    color: var(--primary-color);
}

/* Dropdown Menu */
.dropdown {
    position: relative;
    display: inline-block;
}

.dropdown-toggle {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    cursor: pointer;
    padding: 10px 0;
}

.dropdown-menu {
    display: none;
    position: absolute;
    background-color: var(--white);
    min-width: 200px;
    box-shadow: 0 8px 16px rgba(0,0,0,0.1);
    z-index: 1;
    border-radius: 8px;
    padding: 10px 0;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
}

.dropdown:hover .dropdown-menu {
    display: block;
}

.dropdown-menu a {
    color: var(--text-color);
    padding: 12px 16px;
    text-decoration: none;
    display: block;
    font-size: 0.9rem;
    transition: background-color 0.2s;
}

.dropdown-menu a:hover {
    background-color: var(--light-bg);
    color: var(--primary-color);
}

.dropdown-menu i {
    width: 20px;
    margin-right: 5px;
    color: #999;
}

.btn {
    display: inline-block;
    padding: 10px 20px;
    background-color: var(--primary-color);
    color: var(--white);
    border-radius: 5px;
    text-decoration: none;
    font-weight: bold;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
}

.btn:hover {
    background-color: #06ad56;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(7, 193, 96, 0.3);
}

.btn-large {
    padding: 15px 40px;
    font-size: 1.2rem;
}

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

.btn-outline:hover {
    background-color: var(--primary-color);
    color: var(--white);
    box-shadow: 0 4px 8px rgba(7, 193, 96, 0.3);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #f5f7fa 0%, #e4e8eb 100%);
    padding: 100px 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle, rgba(7, 193, 96, 0.1) 0%, rgba(255,255,255,0) 70%);
    z-index: 0;
}

.hero .container {
    position: relative;
    z-index: 1;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 20px;
    color: var(--secondary-color);
    font-weight: 800;
}

.hero p {
    font-size: 1.3rem;
    margin-bottom: 40px;
    color: #555;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 50px;
    margin-top: 60px;
}

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

.stat-item strong {
    display: block;
    font-size: 2.5rem;
    color: var(--primary-color);
    font-weight: 700;
}

.stat-item span {
    color: #777;
    font-size: 1rem;
}

/* Features Section */
.features {
    padding: 80px 0;
    background-color: var(--white);
}

.section-title {
    text-align: center;
    font-size: 2.2rem;
    margin-bottom: 60px;
    color: var(--secondary-color);
    font-weight: 700;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.feature-card {
    background: var(--white);
    padding: 40px 30px;
    border-radius: 15px;
    box-shadow: var(--card-shadow);
    text-align: center;
    transition: transform 0.3s, box-shadow 0.3s;
    border: 1px solid #f0f0f0;
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.1);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 25px;
    color: var(--primary-color);
    background: rgba(7, 193, 96, 0.1);
    width: 80px;
    height: 80px;
    line-height: 80px;
    border-radius: 50%;
    margin-left: auto;
    margin-right: auto;
}

.feature-card h3 {
    margin-bottom: 15px;
    color: var(--secondary-color);
    font-size: 1.3rem;
}

.feature-card p {
    color: #666;
    font-size: 0.95rem;
}

/* Supported Platforms */
.platforms {
    padding: 60px 0;
    background-color: var(--light-bg);
    text-align: center;
}

.platform-logos {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 40px;
    margin-top: 40px;
}

.platform-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 100px;
    transition: transform 0.3s;
}

.platform-item:hover {
    transform: translateY(-5px);
}

.platform-item img {
    width: 70px;
    height: 70px;
    margin-bottom: 15px;
    border-radius: 18px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.08);
    background: #fff;
    padding: 5px;
}

.platform-item span {
    font-weight: 500;
    color: #555;
}

/* Benefits Section */
.benefits {
    padding: 100px 0;
}

.benefit-row {
    display: flex;
    align-items: center;
    gap: 80px;
    margin-bottom: 100px;
}

.benefit-row:last-child {
    margin-bottom: 0;
}

.benefit-row:nth-child(even) {
    flex-direction: row-reverse;
}

.benefit-content {
    flex: 1;
}

.benefit-content h3 {
    font-size: 2rem;
    margin-bottom: 20px;
    color: var(--secondary-color);
    font-weight: 700;
}

.benefit-content p {
    font-size: 1.1rem;
    color: #666;
    margin-bottom: 0;
}

.benefit-image {
    flex: 1;
    background-color: #f8f9fa;
    height: 350px;
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: #999;
    box-shadow: var(--card-shadow);
    border: 1px solid #eee;
}

/* Pricing Section */
.pricing {
    padding: 80px 0;
    background-color: var(--white);
}

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.pricing-card {
    background: var(--white);
    border: 1px solid #eee;
    border-radius: 15px;
    padding: 40px;
    text-align: center;
    transition: transform 0.3s, box-shadow 0.3s;
    position: relative;
    overflow: hidden;
}

.pricing-card.recommended {
    border-color: var(--primary-color);
    box-shadow: 0 10px 30px rgba(7, 193, 96, 0.1);
    transform: scale(1.05);
    z-index: 1;
}

.pricing-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.1);
}

.pricing-card.recommended:hover {
    transform: scale(1.05) translateY(-5px);
}

.pricing-card .badge {
    position: absolute;
    top: 20px;
    right: -30px;
    background: var(--primary-color);
    color: #fff;
    padding: 5px 30px;
    transform: rotate(45deg);
    font-size: 0.8rem;
    font-weight: bold;
}

.pricing-card h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: var(--secondary-color);
}

.pricing-card .price {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--primary-color);
    margin-bottom: 10px;
}

.pricing-card .price span {
    font-size: 1rem;
    color: #999;
    font-weight: normal;
}

.pricing-card ul {
    list-style: none;
    padding: 0;
    margin-top: 20px;
    text-align: left;
}

.pricing-card ul li {
    padding: 10px 0;
    border-bottom: 1px solid #f5f5f5;
    color: #666;
}

.pricing-card ul li:last-child {
    border-bottom: none;
}

.pricing-card ul li i {
    color: var(--primary-color);
    margin-right: 10px;
}

/* FAQ Section */
.faq {
    padding: 80px 0;
    background-color: var(--light-bg);
}

.faq-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 30px;
}

.faq-item {
    background: var(--white);
    padding: 30px;
    border-radius: 10px;
    box-shadow: var(--shadow);
}

.faq-item h4 {
    color: var(--secondary-color);
    margin-bottom: 15px;
    font-size: 1.1rem;
    display: flex;
    align-items: flex-start;
}

.faq-item h4 i {
    color: var(--primary-color);
    margin-right: 10px;
    margin-top: 3px;
}

.faq-item p {
    color: #666;
    font-size: 0.95rem;
    margin-left: 28px;
}

/* Testimonials Section */
.testimonials {
    padding: 80px 0;
    background-color: var(--white);
}

.testimonial-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.testimonial-card {
    background: var(--light-bg);
    padding: 30px;
    border-radius: 15px;
    position: relative;
    border: 1px solid #eee;
}

.testimonial-quote {
    font-size: 1rem;
    color: #555;
    margin-bottom: 20px;
    font-style: italic;
    line-height: 1.6;
}

.testimonial-author {
    display: flex;
    align-items: center;
    border-top: 1px solid #e0e0e0;
    padding-top: 15px;
}

.author-info strong {
    display: block;
    color: var(--secondary-color);
    font-size: 1rem;
}

.author-info span {
    font-size: 0.85rem;
    color: #888;
}

.author-info .stars {
    color: #ffc107;
    font-size: 0.8rem;
    margin-top: 5px;
}

/* Download Section */
.download {
    padding: 100px 0;
    background: linear-gradient(135deg, #1f2937 0%, #111827 100%);
    color: var(--white);
    text-align: center;
}

.download h2 {
    color: var(--white);
    margin-bottom: 20px;
    font-size: 2.5rem;
}

.download p {
    color: #9ca3af;
    margin-bottom: 50px;
    font-size: 1.2rem;
}

.download-card {
    background: rgba(255, 255, 255, 0.05);
    padding: 50px;
    border-radius: 20px;
    max-width: 700px;
    margin: 0 auto;
    border: 1px solid rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
}

.version-info {
    margin-bottom: 40px;
}

.download-note {
    margin-top: 20px;
    font-size: 0.9rem;
    opacity: 0.6;
}

/* CTA Section */
.cta {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 80px 0;
    text-align: center;
}

.cta h2 {
    margin-bottom: 20px;
    font-size: 2rem;
}

.cta .btn {
    background-color: var(--white);
    color: var(--primary-color);
    font-size: 1.2rem;
    padding: 15px 40px;
    margin-top: 20px;
}

.cta .btn:hover {
    background-color: #f0f0f0;
    transform: translateY(-2px);
}

/* Footer */
footer {
    background-color: #1a1a1a;
    color: #999;
    padding: 30px 0;
    text-align: center;
    border-top: 1px solid #333;
}

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

/* Mobile Responsiveness */
@media (max-width: 768px) {
    .nav-links {
        display: none; /* Simple hiding for now, can be hamburger later */
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 20px;
    }
    
    .benefit-row {
        flex-direction: column;
        gap: 30px;
    }
    
    .benefit-row:nth-child(even) {
        flex-direction: column;
    }
    
    .download-card {
        padding: 25px;
    }
    
    .pricing-card.recommended {
        transform: none;
    }
    
    .pricing-card.recommended:hover {
        transform: translateY(-5px);
    }
}