/* Liangxinyun Custom CSS - Professional and Accessible aesthetics */

:root {
    --primary: #0088ff;
    --primary-alt: #005fcc;
    --secondary: #00bfff;
    --accent: #ffb703;
    --bg-dark: #0f1115;
    --bg-card: rgba(26, 29, 36, 0.7);
    --text-light: #f8f9fa;
    --text-dim: #aeb4c0;
    --glass-border: rgba(255, 255, 255, 0.08);
}

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

body {
    font-family: 'Noto Sans SC', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-light);
    line-height: 1.65;
    overflow-x: hidden;
}

/* Background Atmosphere */
.bg-glow {
    position: fixed;
    top: 0; left: 0; width: 100vw; height: 100vh;
    background: radial-gradient(circle at 15% 50%, rgba(0, 136, 255, 0.08), transparent 45%),
                radial-gradient(circle at 85% 30%, rgba(0, 191, 255, 0.07), transparent 50%);
    z-index: -1;
    animation: bgPulse 8s ease-in-out infinite alternate;
}

.bg-particles {
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    background-image: 
        radial-gradient(rgba(255, 255, 255, 0.12) 1px, transparent 1px),
        radial-gradient(rgba(0, 191, 255, 0.15) 1.5px, transparent 1.5px);
    background-size: 60px 60px, 130px 130px;
    background-position: 0 0, 0 0;
    animation: particleAnimation 60s linear infinite;
}

@keyframes particleAnimation {
    0% { background-position: 0 0, 0 0; }
    100% { background-position: 600px 600px, -650px 650px; }
}

@keyframes bgPulse {
    0% { opacity: 0.85; }
    100% { opacity: 1; }
}

/* Container for constrained width */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 5%;
}

/* Typography */
h1, h2, h3 {
    font-weight: 800;
    line-height: 1.2;
}

/* Navigation */
nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.2rem 5%;
    position: sticky;
    top: 0;
    background: rgba(15, 17, 21, 0.85);
    backdrop-filter: blur(12px);
    z-index: 1000;
    border-bottom: 1px solid var(--glass-border);
}

.logo a {
    font-size: 1.6rem;
    font-weight: 900;
    background: linear-gradient(90deg, #0088ff, #00bfff);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    text-decoration: none;
    letter-spacing: 1px;
}

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

.nav-links a {
    color: var(--text-dim);
    text-decoration: none;
    margin-left: 2rem;
    font-size: 1rem;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: #fff;
}

.nav-links .nav-cta {
    padding: 0.5rem 1.2rem;
    font-size: 0.95rem;
    border-radius: 8px;
    background: var(--primary);
    color: #fff;
    margin-left: 2rem;
}

.nav-links .nav-cta:hover {
    background: var(--primary-alt);
    color: #fff;
}

/* Hero Section */
.hero {
    min-height: 85vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 4rem 5%;
}

.hero h1 {
    font-size: clamp(2.5rem, 6vw, 4.2rem);
    background: linear-gradient(135deg, #fff 40%, var(--secondary));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 1.5rem;
    animation: fadeIn 0.8s ease-out;
}

.hero p {
    font-size: 1.25rem;
    color: var(--text-dim);
    max-width: 800px;
    margin-bottom: 3rem;
    animation: fadeIn 1s ease-out 0.2s both;
}

.hero-actions {
    display: flex;
    gap: 1.5rem;
    animation: fadeIn 1s ease-out 0.4s both;
}

.cta-button {
    padding: 1rem 2.5rem;
    font-size: 1.1rem;
    font-weight: 700;
    border-radius: 50px;
    text-decoration: none;
    transition: transform 0.2s, box-shadow 0.2s, background 0.3s;
}

.primary-btn {
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    color: #fff;
    box-shadow: 0 8px 25px rgba(0, 136, 255, 0.3);
}

.primary-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 30px rgba(0, 136, 255, 0.4);
}

.secondary-btn {
    background: rgba(255,255,255,0.05);
    color: #fff;
    border: 1px solid rgba(255,255,255,0.2);
}

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

/* Base Sections */
section {
    padding: 5rem 0;
}

.section-header {
    text-align: center;
    margin-bottom: 3.5rem;
}

.section-header h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: #fff;
}

.section-subtitle {
    font-size: 1.15rem;
    color: var(--text-dim);
    max-width: 700px;
    margin: 0 auto;
}

.grid {
    display: grid;
    gap: 2rem;
}

/* Feature Cards */
.feature-grid {
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.card {
    background: var(--bg-card);
    border: 1px solid var(--glass-border);
    padding: 2.5rem;
    border-radius: 16px;
    transition: transform 0.3s, background 0.3s;
}

.card:hover {
    transform: translateY(-5px);
    background: rgba(35, 39, 48, 0.8);
    border-color: rgba(0, 136, 255, 0.3);
}

.card .icon {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
}

.card h3 {
    font-size: 1.4rem;
    margin-bottom: 1rem;
    color: #fff;
}

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

/* Pricing Grid */
.pricing-section {
    background: linear-gradient(180deg, transparent, rgba(0, 136, 255, 0.03));
}

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

.pricing-card {
    background: var(--bg-card);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    padding: 3rem 2.5rem;
    position: relative;
    display: flex;
    flex-direction: column;
    text-align: center;
    transition: transform 0.3s;
}

.pricing-card.featured {
    border: 2px solid var(--primary);
    transform: scale(1.03);
    background: rgba(0, 136, 255, 0.05);
}

.pricing-card:hover {
    transform: translateY(-8px);
}

.pricing-card.featured:hover {
    transform: scale(1.03) translateY(-8px);
}

.badge {
    position: absolute;
    top: -14px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary);
    color: #fff;
    padding: 0.4rem 1.2rem;
    border-radius: 20px;
    font-weight: 700;
    font-size: 0.9rem;
    box-shadow: 0 4px 10px rgba(0, 136, 255, 0.3);
}

.badge.discount {
    background: var(--accent);
    color: #000;
    box-shadow: 0 4px 10px rgba(255, 183, 3, 0.3);
}

.pricing-card h3 {
    font-size: 1.6rem;
    margin-bottom: 1rem;
    color: #fff;
}

.price {
    font-size: 3.5rem;
    font-weight: 900;
    color: #fff;
    display: flex;
    justify-content: center;
    align-items: baseline;
    margin-bottom: 0.5rem;
}

.price span { font-size: 1.2rem; margin-right: 0.2rem; color: var(--text-dim); }
.price em { font-style: normal; font-size: 1.1rem; color: var(--text-dim); margin-left: 0.3rem;}

.monthly-price-sub {
    font-size: 0.9rem;
    color: var(--accent);
    margin-bottom: 1rem;
    height: 1.5rem;
}

.plan-desc {
    color: var(--text-dim);
    margin-bottom: 2rem;
    font-size: 0.95rem;
}

.plan-features {
    list-style: none;
    text-align: left;
    margin-bottom: 3rem;
    flex-grow: 1;
}

.plan-features li {
    padding: 0.6rem 0;
    border-bottom: 1px solid rgba(255,255,255,0.05);
    color: var(--text-light);
    font-size: 0.95rem;
    position: relative;
    padding-left: 1.5rem;
}

.plan-features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--secondary);
    font-weight: bold;
}

.price-btn {
    display: inline-block;
    width: 100%;
    padding: 1rem;
    border-radius: 12px;
    font-weight: 700;
    text-decoration: none;
    transition: all 0.2s;
    background: rgba(255,255,255,0.05);
    color: #fff;
    border: 1px solid rgba(255,255,255,0.1);
}

.pricing-card.featured .price-btn {
    background: var(--primary);
    border: none;
    box-shadow: 0 4px 15px rgba(0, 136, 255, 0.4);
}

.price-btn:hover {
    background: rgba(255,255,255,0.1);
}

.pricing-card.featured .price-btn:hover {
    background: var(--primary-alt);
}

/* Pricing Table */
.pricing-table-wrapper {
    width: 100%;
    overflow-x: auto;
    background: var(--bg-card);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 1rem 0;
}

.pricing-table {
    width: 100%;
    min-width: 700px;
    border-collapse: collapse;
    text-align: center;
}

.pricing-table th, .pricing-table td {
    padding: 1.5rem 1rem;
    border-bottom: 1px solid rgba(255,255,255,0.05);
}

.pricing-table th {
    color: var(--text-dim);
    font-weight: 500;
    font-size: 1.1rem;
    padding-top: 0.5rem;
}

.pricing-table td {
    color: var(--text-light);
    font-size: 1.1rem;
}

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

.pricing-table tbody tr:hover {
    background: rgba(255, 255, 255, 0.03);
}

.pricing-table strong {
    color: #fff;
    font-weight: 700;
}

/* Nodes Section */
.node-grid {
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 1.5rem;
}
.node-card {
    background: rgba(255,255,255,0.02);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 1.5rem 1rem;
    text-align: center;
}
.node-flag { font-size: 2rem; margin-bottom: 0.5rem; }
.node-name { font-size: 1rem; margin-bottom: 1rem; font-weight: 500;}
.latency {
    display: inline-block;
    padding: 0.2rem 0.8rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: bold;
}
.latency.low { color: #00ff88; background: rgba(0, 255, 136, 0.1); }
.latency.mid { color: #ffcc00; background: rgba(255, 204, 0, 0.1); }
.latency.high { color: #ff4444; background: rgba(255, 68, 68, 0.1); }

/* Knowledge Base */
.knowledge-section {
    background: #0a0b0e;
}
.kb-grid {
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
}
.kb-card {
    padding: 2rem;
    background: var(--bg-card);
    border-radius: 12px;
    border: 1px solid transparent;
    transition: border 0.3s;
}
.kb-card:hover { border-color: var(--primary); }
.kb-card h3 { margin-bottom: 1rem; font-size: 1.3rem; line-height: 1.4; }
.kb-card a { color: #fff; text-decoration: none; transition: color 0.2s;}
.kb-card h3 a:hover { color: var(--primary); text-decoration: underline; }
.kb-card p { color: var(--text-dim); margin-bottom: 1.5rem; font-size: 0.95rem; }
.kb-link { color: var(--primary)!important; font-weight: bold; }

/* FAQ Section */
.faq-grid {
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
}
.faq-card h3 { font-size: 1.2rem; color: var(--secondary); margin-bottom: 0.8rem; }
.faq-card p { color: var(--text-dim); line-height: 1.6; }

/* Footer */
footer {
    border-top: 1px solid var(--glass-border);
    padding: 4rem 0 2rem;
    background: #050608;
}
.footer-content {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 2rem;
    margin-bottom: 3rem;
}
.footer-logo {
    font-size: 1.5rem;
    font-weight: 900;
    color: #fff;
    margin-bottom: 0.5rem;
}
.footer-brand p { color: var(--text-dim); }
.footer-links a {
    color: var(--text-dim);
    text-decoration: none;
    margin-left: 1.5rem;
    transition: color 0.2s;
}
.footer-links a:hover { color: #fff; }
.copyright {
    text-align: center;
    color: rgba(255,255,255,0.3);
    font-size: 0.85rem;
    border-top: 1px solid var(--glass-border);
    padding-top: 2rem;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 768px) {
    .nav-links { display: none; /* simple mobile behavior */ }
    .hero-actions { flex-direction: column; }
    .pricing-card.featured { transform: scale(1); }
    .pricing-card.featured:hover { transform: translateY(-5px); }
}