:root {
    /* Default Dark UI (Warm, Human-centric) */
    --bg-color: #131418;
    --bg-alt: #1a1c22;
    --text-primary: #F5F5F7;
    --text-secondary: #9ca3af;
    --accent-color: #E5A93C; /* Amber-gold */
    --accent-hover: #c48b29;
    --card-bg: rgba(30, 32, 38, 0.6);
    --border-color: rgba(255, 255, 255, 0.06);
    --pill-bg: rgba(229, 169, 60, 0.1);
    
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
    --transition: all 0.4s cubic-bezier(0.25, 1, 0.5, 1); /* Fluid spring-like physics */
    
    /* Mouse tracking vars (updated by JS) */
    --mouse-x: 50%;
    --mouse-y: 50%;
}

[data-theme="light"] {
    --bg-color: #F9FAFB;
    --bg-alt: #ffffff;
    --text-primary: #111827;
    --text-secondary: #4b5563;
    --accent-color: #D97706;
    --accent-hover: #b45309;
    --card-bg: #ffffff;
    --border-color: rgba(0, 0, 0, 0.1);
    --pill-bg: rgba(217, 119, 6, 0.1);
    --shadow: 0 4px 20px -2px rgba(0, 0, 0, 0.05);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.7;
    transition: background-color var(--transition), color var(--transition);
    overflow-x: hidden;
}

h1, h2, h3, h4, .brand {
    font-family: 'Plus Jakarta Sans', sans-serif;
}

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

.accent-text {
    color: var(--accent-color);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

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

/* Ambient Hearth Glow */
.ambient-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    pointer-events: none;
    z-index: 0;
    background: radial-gradient(circle at var(--mouse-x) var(--mouse-y), rgba(229, 169, 60, 0.03), transparent 40%);
    transition: background 0.1s ease;
}

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(19, 20, 24, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
}

[data-theme="light"] .navbar {
    background-color: rgba(255, 255, 255, 0.8);
}

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

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

.brand {
    font-size: 1.4rem;
    font-weight: 700;
}

/* Status Pill */
.status-pill {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 6px 12px;
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.status-dot {
    width: 8px;
    height: 8px;
    background-color: #10B981; /* Green */
    border-radius: 50%;
    box-shadow: 0 0 8px #10B981;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% { transform: scale(0.95); opacity: 0.8; }
    50% { transform: scale(1.1); opacity: 1; }
    100% { transform: scale(0.95); opacity: 0.8; }
}

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

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

.nav-links a:hover, .nav-links a.highlight-link {
    color: var(--text-primary);
}

.highlight-link {
    position: relative;
}
.highlight-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--accent-color);
    border-radius: 2px;
}

/* Theme Toggle */
.theme-toggle {
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: 50%;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--text-primary);
    transition: var(--transition);
    position: relative;
}

.theme-toggle:hover {
    background-color: var(--pill-bg);
    color: var(--accent-color);
}

.sun-icon, .moon-icon { position: absolute; transition: var(--transition); }
[data-theme="dark"] .sun-icon { opacity: 1; transform: rotate(0); }
[data-theme="dark"] .moon-icon { opacity: 0; transform: rotate(90deg); }
[data-theme="light"] .sun-icon { opacity: 0; transform: rotate(-90deg); }
[data-theme="light"] .moon-icon { opacity: 1; transform: rotate(0); }

/* Buttons */
.btn {
    display: inline-block;
    padding: 14px 32px;
    border-radius: 12px;
    font-weight: 600;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    border: 1px solid transparent;
}

.btn-primary {
    background-color: var(--accent-color);
    color: #131418;
}

.btn-primary:hover {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(229, 169, 60, 0.3);
}

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

.btn-outline:hover {
    border-color: var(--accent-color);
    color: var(--accent-color);
}

/* Layout Utilities */
.section { padding: 100px 0; position: relative; z-index: 1; }
.hero { padding: 180px 0 120px; }
.section-title { font-size: 2.5rem; margin-bottom: 50px; text-align: center; }

.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }

/* Hero Section */
.hero-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    position: relative;
}

.headline {
    font-size: 4rem;
    line-height: 1.1;
    margin-bottom: 24px;
    letter-spacing: -0.02em;
}

.subheadline {
    font-size: 1.2rem;
    color: var(--text-secondary);
    max-width: 650px;
    margin-bottom: 40px;
}

/* World Node Ring Animation */
.world-node-ring {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 600px;
    height: 600px;
    z-index: -1;
    opacity: 0.15;
    pointer-events: none;
}

.ring {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    border: 1px dashed var(--accent-color);
    border-radius: 50%;
}
.r1 { width: 300px; height: 300px; animation: spin 20s linear infinite; }
.r2 { width: 450px; height: 450px; animation: spin 30s linear infinite reverse; }
.r3 { width: 600px; height: 600px; border: 1px solid var(--border-color); }

.node {
    position: absolute;
    width: 12px;
    height: 12px;
    background: var(--accent-color);
    border-radius: 50%;
    box-shadow: 0 0 15px var(--accent-color);
}
.n1 { top: 0; left: 50%; }
.n2 { bottom: 20%; right: 10%; }
.n3 { top: 30%; left: 10%; }

@keyframes spin { 100% { transform: translate(-50%, -50%) rotate(360deg); } }

/* Cards & Bento Box */
.card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 18px; /* 18px rounded geometry */
    padding: 32px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    position: relative;
    /* overflow: hidden; 移除，以免遮挡上方绝对定位的 badge */
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.4);
}
[data-theme="light"] .card:hover {
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.1);
}

/* Spot light glow effect on cards applied via JS */
.glow-card::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(300px circle at var(--local-mouse-x, -100px) var(--local-mouse-y, -100px), rgba(255,255,255,0.04), transparent);
    pointer-events: none;
    z-index: 0;
    transition: opacity 0.3s;
    opacity: 0;
    border-radius: inherit; /* 继承卡片圆角，确保发光不溢出 */
}
.glow-card:hover::before { opacity: 1; }

.card > * { position: relative; z-index: 1; }

.card-icon {
    font-size: 2rem;
    margin-bottom: 20px;
}

.card h3 {
    font-size: 1.3rem;
    margin-bottom: 12px;
}
.card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.card-tag {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 20px;
    background: var(--pill-bg);
    color: var(--text-primary);
    font-size: 0.8rem;
    font-weight: 600;
    margin-bottom: 20px;
}
.card-tag.accent { color: var(--accent-color); }

/* Pricing Slider (Spring physics) */
.pricing-subtitle { text-align: center; color: var(--text-secondary); margin: -30px 0 40px; }

.billing-toggle {
    display: inline-flex;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 30px;
    padding: 6px;
    position: relative;
    margin-bottom: 50px;
}

.toggle-slider {
    position: absolute;
    top: 6px;
    left: 6px;
    height: calc(100% - 12px);
    width: calc(33.33% - 4px);
    background: var(--accent-color);
    border-radius: 24px;
    transition: transform 0.5s cubic-bezier(0.34, 1.56, 0.64, 1); /* Spring physics */
    z-index: 0;
}

.toggle-btn {
    position: relative;
    z-index: 1;
    border: none;
    background: transparent;
    padding: 10px 24px;
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
    transition: color 0.3s;
    width: 120px;
}

.toggle-btn.active { color: #131418; }
[data-theme="light"] .toggle-btn.active { color: #ffffff; }

.discount {
    font-size: 0.7rem;
    background: rgba(16, 185, 129, 0.2);
    color: #10B981;
    padding: 2px 6px;
    border-radius: 10px;
    margin-left: 4px;
    position: absolute;
    top: -10px;
    right: 0;
}

/* Pricing Cards */
.pricing-card {
    text-align: center;
    display: flex;
    flex-direction: column;
}

.pricing-card.popular {
    border-color: var(--accent-color);
    transform: translateY(-10px);
}

.pricing-card.popular:hover {
    transform: translateY(-15px);
    box-shadow: 0 12px 32px rgba(229, 169, 60, 0.15);
}

.badge {
    position: absolute;
    top: 0;
    left: 50%;
    transform: translate(-50%, -50%);
    background: var(--accent-color);
    color: #131418;
    padding: 4px 16px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 700;
}

.price {
    font-size: 3.5rem;
    font-family: 'Plus Jakarta Sans', monospace;
    font-weight: 700;
    margin: 24px 0;
    line-height: 1;
}

.price .currency, .price .period {
    font-size: 1rem;
    color: var(--text-secondary);
    font-family: 'Inter', sans-serif;
    font-weight: 400;
}

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

.features-list li {
    padding: 12px 0;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.95rem;
    display: flex;
    align-items: center;
    gap: 10px;
}
.features-list li::before { content: '✓'; color: var(--accent-color); font-weight: bold; }
.features-list li:last-child { border-bottom: none; }

/* Community Wall & Node Feedback */
.testimonial-item {
    margin-bottom: 24px;
    padding-bottom: 24px;
    border-bottom: 1px solid var(--border-color);
}
.testimonial-item:last-child { border: none; padding: 0; margin: 0; }
.testimonial-text { font-style: italic; margin-bottom: 12px; }
.testimonial-author { font-weight: 600; font-size: 0.9rem; }

.node-subtitle { color: var(--text-secondary); font-size: 0.9rem; margin-bottom: 20px; }
.node-pills { display: flex; gap: 12px; margin-bottom: 24px; }
.node-pill {
    background: transparent;
    border: 1px solid var(--border-color);
    padding: 8px 16px;
    border-radius: 20px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition);
    font-family: inherit;
    font-weight: 500;
}
.node-pill:hover, .node-pill.active {
    background: var(--pill-bg);
    border-color: var(--accent-color);
    color: var(--accent-color);
}

.stat-group { display: none; animation: fadeIn 0.4s ease; }
.stat-group.active { display: block; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }

.stat-row {
    display: flex;
    justify-content: space-between;
    padding: 12px 0;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.95rem;
}
.stat-row:last-child { border: none; }

/* FAQ */
.faq-list { max-width: 800px; margin: 0 auto; display: flex; flex-direction: column; gap: 20px; }
.faq-item { padding: 24px; }
.faq-item h4 { font-size: 1.1rem; margin-bottom: 12px; }

/* Footer */
.footer {
    padding: 60px 0 40px;
    border-top: 1px solid var(--border-color);
    text-align: center;
}
.footer-links { margin-bottom: 24px; display: flex; justify-content: center; gap: 30px; }
.footer-links a { color: var(--text-secondary); font-size: 0.95rem; }
.footer-links a:hover { color: var(--text-primary); }
.copyright { color: var(--text-secondary); font-size: 0.85rem; }

/* Responsive */
@media (max-width: 992px) {
    .headline { font-size: 3rem; }
    .grid-3 { grid-template-columns: 1fr; }
    .grid-2 { grid-template-columns: 1fr; }
    .pricing-card.popular { transform: none; }
    .nav-links { display: none; } /* Mobile menu could be added here */
}

@media (max-width: 768px) {
    .status-pill { display: none; }
    .btn { width: 100%; }
    .world-node-ring { transform: translate(-50%, -50%) scale(0.6); }
    .toggle-btn { width: 90px; padding: 10px 12px; font-size: 0.85rem; }
}