:root {
    --bg-main: #F8FAFC;         /* Light grayish blue for SaaS feel */
    --bg-white: #FFFFFF;
    --text-primary: #1E293B;    /* Graphite black */
    --text-secondary: #64748B;  /* Muted slate */
    --border-light: #E2E8F0;    /* Thin borders */
    --accent-wechat: #07C160;   /* WeChat Green for trust & conversion */
    --accent-wechat-hover: #06ad56;
    --accent-dark: #0F172A;     /* Dark accent for primary non-payment actions */
    --accent-dark-hover: #1e293b;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-main);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

a {
    text-decoration: none;
    color: inherit;
}

/* Typography Defaults */
h1, h2, h3, h4, h5, h6 {
    color: var(--text-primary);
    letter-spacing: -0.025em;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 20px;
    border-radius: 6px; /* Slightly squarer for B2B feel */
    font-weight: 500;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn-primary {
    background-color: var(--accent-dark);
    color: #fff;
    box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
    background-color: var(--accent-dark-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background-color: var(--bg-white);
    border: 1px solid var(--border-light);
    color: var(--text-primary);
    box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
    background-color: #F1F5F9;
    border-color: #CBD5E1;
}

.btn-text {
    background: transparent;
    color: var(--text-secondary);
    font-weight: 500;
}

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

/* Header */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 5%;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-light);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 40px;
}

.logo {
    font-size: 20px;
    font-weight: 800;
    color: var(--text-primary);
    letter-spacing: -0.5px;
}

.main-nav {
    display: flex;
    gap: 24px;
}

.main-nav a {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-secondary);
    transition: color 0.2s;
}

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

.header-right {
    display: flex;
    align-items: center;
    gap: 20px;
}

.status-indicator {
    font-size: 13px;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 500;
}

.status-indicator .dot {
    width: 8px;
    height: 8px;
    background-color: var(--accent-wechat);
    border-radius: 50%;
    box-shadow: 0 0 0 3px rgba(7, 193, 96, 0.2);
}

/* Hero Section (2-Column) */
.hero {
    padding: 80px 5% 100px;
    background: var(--bg-white);
    border-bottom: 1px solid var(--border-light);
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-content {
    max-width: 580px;
}

.hero-title {
    font-size: 46px;
    font-weight: 800;
    line-height: 1.15;
    margin-bottom: 24px;
    color: var(--text-primary);
}

.hero-subtitle {
    font-size: 18px;
    font-weight: 400;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 40px;
}

.hero-cta {
    display: flex;
    align-items: center;
    gap: 20px;
    margin-bottom: 30px;
}

.hero-cta .btn-primary {
    padding: 14px 28px;
    font-size: 16px;
    border-radius: 8px;
}

.hero-trust {
    display: flex;
    gap: 20px;
    font-size: 13px;
    color: var(--text-secondary);
    font-weight: 500;
}

/* Dynamic Visual (Hero Right) */
.hero-visual {
    position: relative;
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}

.server-stack {
    width: 100%;
    max-width: 400px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    position: relative;
}

.server-card {
    background: var(--bg-white);
    border: 1px solid var(--border-light);
    border-radius: 8px;
    padding: 16px 20px;
    box-shadow: var(--shadow-md);
    animation: float 6s ease-in-out infinite;
}

.server-card.delay-1 { animation-delay: 2s; }
.server-card.delay-2 { animation-delay: 4s; }

@keyframes float {
    0% { transform: translateY(0px); }
    50% { transform: translateY(-8px); }
    100% { transform: translateY(0px); }
}

.node-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: 12px;
    font-size: 14px;
    font-weight: 600;
}

.ping { font-family: monospace; }
.ping-excellent { color: var(--accent-wechat); }
.ping-good { color: #EAB308; }

.bar-chart {
    height: 4px;
    background: #F1F5F9;
    border-radius: 2px;
    overflow: hidden;
}

.bar-chart .bar {
    height: 100%;
    background: var(--accent-wechat);
    border-radius: 2px;
}

.status-pulse-container {
    position: absolute;
    right: -30px;
    bottom: -20px;
    display: flex;
    align-items: center;
    gap: 12px;
    background: var(--bg-white);
    padding: 12px 20px;
    border-radius: 30px;
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-lg);
}

.pulse-core {
    width: 12px;
    height: 12px;
    background: var(--accent-wechat);
    border-radius: 50%;
    position: relative;
    z-index: 2;
}

.pulse-ring {
    position: absolute;
    left: 12px;
    top: 12px;
    width: 12px;
    height: 12px;
    background: var(--accent-wechat);
    border-radius: 50%;
    animation: pulsate 2s ease-out infinite;
    z-index: 1;
}

.pulse-text {
    font-size: 12px;
    font-weight: 600;
    color: var(--text-primary);
}

@keyframes pulsate {
    0% { transform: scale(1); opacity: 0.8; }
    100% { transform: scale(3.5); opacity: 0; }
}

/* Sections Global */
.section-title {
    text-align: center;
    font-size: 36px;
    font-weight: 800;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.section-subtitle {
    text-align: center;
    font-size: 16px;
    color: var(--text-secondary);
    margin-bottom: 48px;
}

/* Contrast Section */
.contrast {
    padding: 80px 5%;
    max-width: 1000px;
    margin: 0 auto;
}

.table-container {
    background: var(--bg-white);
    border-radius: 12px;
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-sm);
    overflow-x: auto;
}

.contrast-table {
    width: 100%;
    border-collapse: collapse;
    text-align: left;
}

.contrast-table th, .contrast-table td {
    padding: 20px 24px;
    border-bottom: 1px solid var(--border-light);
    font-size: 14px;
}

.contrast-table th {
    background: #F8FAFC;
    font-weight: 600;
    color: var(--text-secondary);
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.contrast-table tr:last-child td {
    border-bottom: none;
}

.contrast-table .col-title {
    font-weight: 600;
    color: var(--text-primary);
}

.contrast-table .highlight-col {
    background: #F0FDF4; /* Very light green tint */
    color: #166534; /* Darker green text */
    font-weight: 600;
}

/* Pricing Section */
.pricing {
    padding: 80px 5% 100px;
    max-width: 1100px;
    margin: 0 auto;
}

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-bottom: 40px;
}

.price-card {
    background: var(--bg-white);
    border: 1px solid var(--border-light);
    border-radius: 12px;
    padding: 40px 32px;
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-sm);
    transition: transform 0.3s, box-shadow 0.3s;
    position: relative;
}

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

.price-card.featured {
    border: 2px solid var(--accent-wechat);
    box-shadow: var(--shadow-lg);
}

.featured-badge {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--accent-wechat);
    color: white;
    padding: 4px 16px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    box-shadow: 0 2px 4px rgba(7, 193, 96, 0.3);
}

.card-header {
    margin-bottom: 24px;
    padding-bottom: 24px;
    border-bottom: 1px solid var(--border-light);
}

.card-title {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.card-price {
    font-size: 40px;
    font-weight: 800;
    color: var(--text-primary);
    line-height: 1;
    margin-bottom: 12px;
}

.card-price span {
    font-size: 16px;
    color: var(--text-secondary);
    font-weight: 500;
}

.card-desc {
    font-size: 13px;
    color: var(--text-secondary);
}

.card-features {
    list-style: none;
    margin-bottom: 32px;
    flex-grow: 1;
}

.card-features li {
    padding: 10px 0;
    color: var(--text-secondary);
    font-size: 14px;
    display: flex;
    align-items: center;
}

.card-features li::before {
    content: '';
    display: inline-block;
    width: 16px;
    height: 16px;
    margin-right: 12px;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20' fill='%2307C160'%3E%3Cpath fill-rule='evenodd' d='M16.707 5.293a1 1 0 010 1.414l-8 8a1 1 0 01-1.414 0l-4-4a1 1 0 011.414-1.414L8 12.586l7.293-7.293a1 1 0 011.414 0z' clip-rule='evenodd'/%3E%3C/svg%3E");
    background-size: contain;
}

.payment-tag {
    font-size: 12px;
    color: var(--accent-wechat);
    margin-bottom: 12px;
    font-weight: 600;
    text-align: center;
}

.btn-buy, .btn-buy-primary {
    width: 100%;
    padding: 14px;
    border-radius: 8px;
    text-align: center;
    font-weight: 600;
    font-size: 15px;
    transition: all 0.2s;
}

.btn-buy {
    background: var(--bg-white);
    color: var(--accent-wechat);
    border: 1px solid var(--accent-wechat);
}

.btn-buy:hover {
    background: #F0FDF4;
}

.btn-buy-primary {
    background: var(--accent-wechat);
    color: white;
    border: 1px solid var(--accent-wechat);
    box-shadow: 0 4px 6px rgba(7, 193, 96, 0.25);
}

.btn-buy-primary:hover {
    background: var(--accent-wechat-hover);
    box-shadow: 0 6px 12px rgba(7, 193, 96, 0.35);
    transform: translateY(-1px);
}

.trust-badge {
    text-align: center;
    color: var(--text-secondary);
    font-size: 14px;
    background: var(--bg-white);
    padding: 16px 32px;
    border-radius: 30px;
    border: 1px solid var(--border-light);
    margin: 0 auto;
    display: flex;
    justify-content: center;
    align-items: center;
    width: fit-content;
    box-shadow: var(--shadow-sm);
}

/* Articles Section */
.articles {
    padding: 80px 5% 100px;
    max-width: 1100px;
    margin: 0 auto;
    border-top: 1px solid var(--border-light);
}

.article-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.article-card {
    background: var(--bg-white);
    border: 1px solid var(--border-light);
    border-radius: 12px;
    padding: 24px;
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
}

.article-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: var(--accent-wechat);
}

.article-badge {
    background: #F1F5F9;
    color: var(--text-secondary);
    font-size: 12px;
    font-weight: 600;
    padding: 4px 10px;
    border-radius: 16px;
    width: fit-content;
    margin-bottom: 12px;
    transition: all 0.2s;
}

.article-card:hover .article-badge {
    background: #F0FDF4;
    color: var(--accent-wechat);
}

.article-card h4 {
    font-size: 16px;
    font-weight: 700;
    margin-bottom: 12px;
    line-height: 1.5;
    color: var(--text-primary);
}

.article-card p {
    font-size: 13px;
    color: var(--text-secondary);
    flex-grow: 1;
    margin-bottom: 20px;
    line-height: 1.6;
}

.read-more {
    font-size: 13px;
    font-weight: 600;
    color: var(--text-primary);
    display: inline-flex;
    align-items: center;
    transition: color 0.2s;
}

.article-card:hover .read-more {
    color: var(--accent-wechat);
}

/* Footer Section */
.footer {
    background: var(--bg-white);
    border-top: 1px solid var(--border-light);
}

.footer-top {
    max-width: 1100px;
    margin: 0 auto;
    padding: 60px 5%;
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 40px;
}

.footer h4 {
    font-size: 14px;
    color: var(--text-primary);
    margin-bottom: 20px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.config-row {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.btn-config {
    background: var(--bg-main);
    border: 1px solid var(--border-light);
    padding: 10px 20px;
    border-radius: 6px;
    font-size: 13px;
    font-weight: 500;
    color: var(--text-primary);
}

.btn-config:hover {
    background: #E2E8F0;
}

.support-links {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.support-link {
    color: var(--text-secondary);
    font-size: 14px;
    transition: color 0.2s;
}

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

.footer-bottom {
    border-top: 1px solid var(--border-light);
    padding: 24px 5%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1100px;
    margin: 0 auto;
    flex-wrap: wrap;
    gap: 20px;
}

.footer-links {
    display: flex;
    gap: 24px;
}

.footer-links a {
    color: var(--text-secondary);
    font-size: 13px;
}

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

.copyright {
    color: var(--text-secondary);
    font-size: 13px;
}

/* Media Queries for Mobile */
@media (max-width: 900px) {
    .hero-container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-content {
        margin: 0 auto;
    }
    
    .hero-cta {
        justify-content: center;
        flex-direction: column;
    }
    
    .hero-cta .btn {
        width: 100%;
        max-width: 300px;
    }
    
    .hero-trust {
        justify-content: center;
        flex-wrap: wrap;
    }

    .server-stack {
        margin: 0 auto;
    }
    
    .status-pulse-container {
        right: 0;
        bottom: -20px;
    }
}

@media (max-width: 768px) {
    .header {
        flex-wrap: wrap;
    }
    
    .main-nav {
        display: none; /* Can add a hamburger menu if needed, keeping simple for now */
    }
    
    .header-left {
        gap: 0;
    }

    .pricing-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }

    .price-card.featured {
        transform: scale(1);
    }
    
    .price-card:hover {
        transform: translateY(-2px);
    }
    
    .footer-top {
        flex-direction: column;
    }
    
    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }
    
    .contrast-table th, .contrast-table td {
        padding: 12px 10px;
    }
}