:root {
    --primary: #6366f1;
    --primary-hover: #4f46e5;
    --bg: #0a0c10;
    /* 更深且具质感的背景色，利于内容突出 */
    --card-bg: #11141b;
    --card-border: rgba(255, 255, 255, 0.05);
    --text: #f9fafb;
    --text-muted: #9ca3af;
    --glass-border: rgba(255, 255, 255, 0.1);
    --accent: #10b981;
}

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

body {
    font-family: 'Inter', 'Noto Sans SC', sans-serif;
    background-color: var(--bg);
    color: var(--text);
    line-height: 1.6;
    overflow-x: hidden;
}

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

header {
    background: rgba(10, 12, 16, 0.8);
    backdrop-filter: blur(10px);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid var(--glass-border);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    letter-spacing: -1px;
}

.logo span {
    color: var(--primary);
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-muted);
    transition: color 0.3s;
}

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

.btn {
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    display: inline-block;
    cursor: pointer;
    text-align: center;
}

.btn-primary {
    background-color: var(--primary);
    color: white;
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(99, 102, 241, 0.4);
}

.btn-secondary {
    background-color: var(--card-bg);
    color: var(--text);
    border: 1px solid var(--glass-border);
}

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

.btn-outline {
    border: 1px solid var(--primary);
    color: var(--primary);
}

.btn-outline:hover {
    background-color: var(--primary);
    color: white;
}

.hero {
    padding: 200px 0 100px;
    display: flex;
    align-items: center;
    gap: 4rem;
}

.hero-content h1 {
    font-size: 4rem;
    line-height: 1.1;
    margin-bottom: 24px;
}

.gradient-text {
    background: linear-gradient(90deg, #6366f1, #a855f7);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-content p {
    font-size: 1.25rem;
    color: var(--text-muted);
    margin-bottom: 40px;
    max-width: 600px;
}

.hero-btns {
    display: flex;
    gap: 1.5rem;
}

.hero-visual {
    position: relative;
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
}

.nodes-container {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--glass-border);
    padding: 2.5rem;
    border-radius: 24px;
    width: 100%;
    max-width: 500px;
    backdrop-filter: blur(10px);
}

.nodes-container h3 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    text-align: center;
    color: var(--text);
}

.nodes-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
}

.node-tag {
    background: rgba(99, 102, 241, 0.08);
    border: 1px solid rgba(99, 102, 241, 0.15);
    padding: 0.6rem 0.4rem;
    border-radius: 12px;
    text-align: center;
    font-size: 0.85rem;
    color: #a5b4fc;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.node-tag span {
    font-size: 0.75rem;
    color: #10b981;
    /* 绿色表示极速延迟 */
    font-weight: 700;
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.node-tag:hover {
    background: var(--primary);
    color: white;
    transform: scale(1.05);
}

.glow-sphere {
    position: absolute;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.2) 0%, transparent 70%);
    border-radius: 50%;
    filter: blur(40px);
    z-index: -1;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 60px;
}

.feature-grid,
.article-grid,
.pricing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 100px;
}

.card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    padding: 2.5rem;
    border-radius: 20px;
    transition: all 0.3s ease;
    text-decoration: none;
    color: inherit;
    display: block;
    /* 确保作为链接时占满空间 */
}

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

/* Pricing Specific */
.pricing-card {
    text-align: center;
    position: relative;
    overflow: hidden;
}

.pricing-card.featured {
    border: 1.5px solid var(--primary);
    box-shadow: 0 0 30px rgba(99, 102, 241, 0.2);
}

.badge {
    position: absolute;
    top: 12px;
    right: -35px;
    background: var(--primary);
    color: white;
    padding: 5px 40px;
    transform: rotate(45deg);
    font-size: 0.75rem;
    font-weight: 700;
}

.price {
    font-size: 3rem;
    font-weight: 800;
    margin: 1.5rem 0;
}

.price span {
    font-size: 1rem;
    color: var(--text-muted);
}

.faq-item p {
    color: #d1d5db;
    /* 比 text-muted 更亮一点，提高可读性 */
}

/* 统一提升文章卡片内的描述文字亮度 */
.article-info p {
    color: #d1d5db;
}

.article-info h3 {
    margin-bottom: 0.5rem;
    color: var(--text);
}

.pricing-features {
    list-style: none;
    margin-bottom: 2rem;
    text-align: left;
}

.pricing-features li {
    margin-bottom: 0.75rem;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: 10px;
}

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

.icon {
    font-size: 3rem;
    margin-bottom: 20px;
}

.tag {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary);
    border-radius: 20px;
    font-size: 0.875rem;
    margin-bottom: 1rem;
}

footer {
    padding: 80px 0 40px;
    border-top: 1px solid var(--glass-border);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    margin-bottom: 60px;
}

.footer-links h4 {
    margin-bottom: 20px;
}

.footer-links ul {
    list-style: none;
}

.footer-links a {
    text-decoration: none;
    color: var(--text-muted);
    transition: color 0.3s;
}

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

.footer-bottom {
    text-align: center;
    padding-top: 40px;
    border-top: 1px solid var(--glass-border);
    color: var(--text-muted);
    font-size: 0.875rem;
}

@media (max-width: 768px) {
    .hero {
        flex-direction: column;
        padding-top: 120px;
        text-align: center;
    }

    .hero-content h1 {
        font-size: 2.5rem;
    }

    .nav-links {
        display: none;
    }
}