:root {
    --primary-color: #8b5cf6;
    --primary-gradient: linear-gradient(135deg, #8b5cf6 0%, #6366f1 100%);
    --bg-dark: #0f172a;
    --bg-card: #1e293b;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --accent-green: #10b981;
    --border-color: #334155;
    --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);
}

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

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-main);
    line-height: 1.6;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color 0.2s;
}

ul {
    list-style: none;
}

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

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    padding: 1rem 0;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-links a {
    color: var(--text-muted);
    font-weight: 500;
}

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

.btn-primary {
    background: var(--primary-gradient);
    color: white !important;
    padding: 0.5rem 1.25rem;
    border-radius: 9999px;
    font-weight: 600;
    transition: transform 0.2s, box-shadow 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(139, 92, 246, 0.3);
}

.btn-secondary {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-main);
    padding: 0.5rem 1.25rem;
    border-radius: 9999px;
    font-weight: 600;
    transition: background 0.2s;
}

.btn-secondary:hover {
    background: var(--bg-card);
}

/* Hero Section */
.hero {
    padding-top: 8rem;
    padding-bottom: 4rem;
    min-height: 90vh;
    display: flex;
    align-items: center;
    background: radial-gradient(circle at 50% 0%, rgba(139, 92, 246, 0.15), transparent 50%);
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-content h1 {
    font-size: 3.5rem;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    font-weight: 800;
}

.gradient-text {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.subtitle {
    font-size: 1.25rem;
    color: var(--text-muted);
    margin-bottom: 2.5rem;
    max-width: 500px;
}

.cta-group {
    display: flex;
    gap: 1rem;
}

.hero-image {
    position: relative;
}

.hero-tags {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 2.5rem;
    flex-wrap: wrap;
}

.hero-tag {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(139, 92, 246, 0.1);
    border: 1px solid rgba(139, 92, 246, 0.2);
    padding: 0.5rem 1rem;
    border-radius: 8px;
    font-size: 0.9rem;
    color: var(--text-main);
    font-weight: 500;
}

.hero-tag i {
    color: var(--accent-green);
}

.hero-screenshot-container {
    position: relative;
    width: 100%;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.2), 0 10px 10px -5px rgba(0, 0, 0, 0.1);
    border: 1px solid var(--border-color);
    background: var(--bg-card);
    transition: transform 0.3s ease;
}

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

.hero-screenshot {
    width: 100%;
    height: auto;
    display: block;
}

/* Language-based image switching */
html[lang="en-US"] .img-cn {
    display: none;
}

html[lang="zh-CN"] .img-en {
    display: none;
}

.code-window {
    background: #000;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    font-family: 'Fira Code', monospace;
}

.window-header {
    background: var(--bg-card);
    padding: 0.75rem 1rem;
    display: flex;
    gap: 0.5rem;
    border-bottom: 1px solid var(--border-color);
}

.dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.red { background: #ef4444; }
.yellow { background: #eab308; }
.green { background: #22c55e; }

.code-window pre {
    padding: 1.5rem;
    color: #a5b4fc;
    font-size: 0.9rem;
    line-height: 1.5;
    overflow-x: auto;
}

/* Features */
.features {
    padding: 6rem 0;
    background: var(--bg-dark);
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 4rem;
    font-weight: 700;
}

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

.feature-card {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: 16px;
    border: 1px solid var(--border-color);
    transition: transform 0.2s, border-color 0.2s;
}

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

.icon-box {
    width: 48px;
    height: 48px;
    background: rgba(139, 92, 246, 0.1);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
}

.feature-card h3 {
    margin-bottom: 1rem;
    font-size: 1.25rem;
}

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

/* Use Cases */
.use-cases {
    padding: 6rem 0;
    background: var(--bg-card);
    border-top: 1px solid var(--border-color);
}

.use-case-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.use-case-card {
    background: var(--bg-dark);
    padding: 2rem;
    border-radius: 16px;
    border: 1px solid var(--border-color);
    position: relative;
    overflow: hidden;
}

.use-case-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--primary-gradient);
}

.use-case-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-main);
}

.use-case-card ul {
    list-style: none;
}

.use-case-card li {
    margin-bottom: 0.75rem;
    color: var(--text-muted);
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
}

.use-case-card li i {
    color: var(--accent-green);
    margin-top: 4px;
}

/* Integrations */
.integrations {
    padding: 4rem 0;
    background: var(--bg-dark);
    border-bottom: 1px solid var(--border-color);
}

.integration-logos {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 3rem;
    opacity: 0.7;
}

.integration-item {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: color 0.2s, opacity 0.2s;
}

.integration-item:hover {
    color: var(--text-main);
    opacity: 1;
}

/* Architecture */
.architecture {
    padding: 6rem 0;
    background: linear-gradient(to bottom, var(--bg-dark), #0f172a);
    border-top: 1px solid var(--border-color);
}

.arch-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.arch-visual {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.layer {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 1.5rem;
    border-radius: 12px;
    width: 100%;
    text-align: center;
    font-weight: 600;
    box-shadow: var(--shadow-md);
}

.layer-core {
    background: rgba(139, 92, 246, 0.05);
    border-color: var(--primary-color);
    padding: 2rem;
}

.core-grid {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 1rem;
    margin-top: 1rem;
}

.core-grid span {
    background: var(--bg-dark);
    padding: 0.5rem;
    border-radius: 8px;
    font-size: 0.85rem;
    color: var(--text-muted);
    border: 1px solid var(--border-color);
}

.arrow-down {
    color: var(--text-muted);
    font-size: 1.5rem;
}

.arch-list li {
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.1rem;
}

.arch-list i {
    color: var(--accent-green);
}

/* Roadmap */
.roadmap {
    padding: 6rem 0;
    background: var(--bg-dark);
}

.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}

.timeline::after {
    content: '';
    position: absolute;
    width: 2px;
    background: var(--border-color);
    top: 0;
    bottom: 0;
    left: 50%;
    margin-left: -1px;
}

.timeline-item {
    padding: 10px 40px;
    position: relative;
    background-color: inherit;
    width: 50%;
}

.timeline-item::after {
    content: '';
    position: absolute;
    width: 16px;
    height: 16px;
    right: -8px;
    background-color: var(--bg-dark);
    border: 2px solid var(--primary-color);
    top: 15px;
    border-radius: 50%;
    z-index: 1;
}

.left {
    left: 0;
}

.right {
    left: 50%;
}

.left::before {
    content: " ";
    height: 0;
    position: absolute;
    top: 22px;
    width: 0;
    z-index: 1;
    right: 30px;
    border: medium solid var(--border-color);
    border-width: 10px 0 10px 10px;
    border-color: transparent transparent transparent var(--border-color);
}

.right::before {
    content: " ";
    height: 0;
    position: absolute;
    top: 22px;
    width: 0;
    z-index: 1;
    left: 30px;
    border: medium solid var(--border-color);
    border-width: 10px 10px 10px 0;
    border-color: transparent var(--border-color) transparent transparent;
}

.right::after {
    left: -8px;
}

.timeline-content {
    padding: 20px 30px;
    background: var(--bg-card);
    position: relative;
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.timeline-content h3 {
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

.timeline-content p {
    font-size: 0.95rem;
    color: var(--text-muted);
}

@media screen and (max-width: 600px) {
  .timeline::after {
    left: 31px;
  }
  
  .timeline-item {
    width: 100%;
    padding-left: 70px;
    padding-right: 25px;
  }
  
  .timeline-item::before {
    left: 60px;
    border: medium solid white;
    border-width: 10px 10px 10px 0;
    border-color: transparent white transparent transparent;
  }

  .left::after, .right::after {
    left: 23px;
  }
  
  .right {
    left: 0%;
  }
}

/* CTA */
.cta-section {
    padding: 6rem 0;
    text-align: center;
    background: radial-gradient(circle at 50% 50%, rgba(99, 102, 241, 0.1), transparent 70%);
}

.cta-section h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.cta-section p {
    color: var(--text-muted);
    margin-bottom: 2rem;
    font-size: 1.25rem;
}

/* Footer */
footer {
    border-top: 1px solid var(--border-color);
    padding: 4rem 0;
    background: var(--bg-dark);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 4rem;
}

.footer-brand h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.footer-brand p {
    color: var(--text-muted);
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.footer-links h4 {
    margin-bottom: 1rem;
    color: var(--text-main);
}

.footer-legal {
    text-align: right;
    grid-column: 1 / -1;
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.85rem;
}

/* Mobile Responsive */
@media (max-width: 768px) {
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }

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

    .subtitle {
        margin: 0 auto 2rem;
    }

    .cta-group {
        justify-content: center;
    }

    .arch-layout {
        grid-template-columns: 1fr;
    }

    .nav-links {
        display: none; /* Simple hiding for mobile, ideally a burger menu */
    }
}

/* Badge */
.badge-container {
    margin-bottom: 1rem;
}

.badge {
    background: rgba(139, 92, 246, 0.1);
    color: var(--primary-color);
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.85rem;
    font-weight: 600;
    border: 1px solid rgba(139, 92, 246, 0.2);
    display: inline-block;
}

/* Vision Section */
.vision-section {
    padding: 6rem 0;
    background: #0f172a; /* Slightly darker than standard bg-dark */
    position: relative;
    overflow: hidden;
}

/* Subtle nebula effect */
.vision-section::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -20%;
    width: 140%;
    height: 140%;
    background: radial-gradient(circle at 50% 50%, rgba(99, 102, 241, 0.05), transparent 60%);
    pointer-events: none;
    z-index: 0;
}

.vision-content {
    text-align: center;
    position: relative;
    z-index: 1;
}

.vision-content h2 {
    font-size: 3rem;
    margin-bottom: 1.5rem;
    font-weight: 800;
}

.vision-text {
    max-width: 700px;
    margin: 0 auto 4rem;
    color: var(--text-muted);
    font-size: 1.25rem;
    line-height: 1.6;
}

.vision-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    text-align: left;
}

.vision-card {
    background: rgba(30, 41, 59, 0.5); /* Semi-transparent bg-card */
    backdrop-filter: blur(10px);
    padding: 2.5rem;
    border-radius: 20px;
    border: 1px solid rgba(51, 65, 85, 0.5);
    transition: transform 0.3s, border-color 0.3s;
}

.vision-card:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
    background: rgba(30, 41, 59, 0.8);
}

.vision-icon {
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.1), rgba(99, 102, 241, 0.1));
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    border: 1px solid rgba(139, 92, 246, 0.2);
}

.vision-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-main);
}

.vision-card p {
    color: var(--text-muted);
    line-height: 1.6;
}

/* Community Vibe (Tweet Style) */
.community-vibe {
    padding: 6rem 0;
    background: var(--bg-card);
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
}

.tweet-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.tweet-card {
    background: var(--bg-dark);
    padding: 2rem;
    border-radius: 16px;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-md);
    transition: transform 0.2s;
}

.tweet-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.tweet-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: #64748b;
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.2rem;
}

.user-info .name {
    font-weight: 700;
    color: var(--text-main);
    font-size: 1rem;
}

.user-info .handle {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.tweet-content {
    color: var(--text-main);
    font-size: 1.05rem;
    line-height: 1.6;
}

.highlight {
    color: var(--primary-color);
    font-weight: 500;
}