/* ===== CSS Variables ===== */
:root {
    --bg-primary: #0a0a0f;
    --bg-secondary: #12121a;
    --bg-tertiary: #1a1a25;
    --bg-card: #15151f;
    --text-primary: #ffffff;
    --text-secondary: #a0a0b0;
    --text-muted: #6a6a7a;
    --accent-primary: #6366f1;
    --accent-secondary: #8b5cf6;
    --accent-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #a855f7 100%);
    --border-color: rgba(255, 255, 255, 0.08);
    --border-light: rgba(255, 255, 255, 0.12);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 40px rgba(99, 102, 241, 0.15);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 30px;
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
    --font-sans: 'Segoe UI', -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Microsoft YaHei', sans-serif;
}

/* ===== Reset & Base ===== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

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

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
}

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

/* ===== Navbar ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(10, 10, 15, 0.85);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    transition: all var(--transition-normal);
}

.navbar.scrolled {
    background: rgba(10, 10, 15, 0.95);
    box-shadow: var(--shadow-md);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.25rem;
    font-weight: 700;
}

.logo-icon {
    font-size: 1.5rem;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.nav-links {
    display: flex;
    gap: 8px;
}

.nav-links a {
    padding: 10px 18px;
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    font-weight: 500;
    transition: all var(--transition-fast);
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--text-primary);
    background: var(--bg-tertiary);
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 16px;
}

.lang-switch {
    padding: 8px 16px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.lang-switch:hover {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
    background: none;
    border: none;
    cursor: pointer;
}

.mobile-menu-btn span {
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all var(--transition-fast);
}

/* ===== Hero Section ===== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 120px 24px 80px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    z-index: 0;
}

.grid-lines {
    position: absolute;
    inset: 0;
    background-image: 
        linear-gradient(rgba(99, 102, 241, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(99, 102, 241, 0.03) 1px, transparent 1px);
    background-size: 60px 60px;
    mask-image: radial-gradient(ellipse at center, black 0%, transparent 70%);
}

.floating-shapes {
    position: absolute;
    inset: 0;
    overflow: hidden;
}

.shape {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.4;
    animation: float 20s ease-in-out infinite;
}

.shape-1 {
    width: 400px;
    height: 400px;
    background: var(--accent-primary);
    top: 10%;
    left: 10%;
    animation-delay: 0s;
}

.shape-2 {
    width: 300px;
    height: 300px;
    background: var(--accent-secondary);
    top: 50%;
    right: 10%;
    animation-delay: -7s;
}

.shape-3 {
    width: 350px;
    height: 350px;
    background: #a855f7;
    bottom: 10%;
    left: 30%;
    animation-delay: -14s;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    25% { transform: translate(30px, -30px) scale(1.05); }
    50% { transform: translate(-20px, 20px) scale(0.95); }
    75% { transform: translate(20px, 30px) scale(1.02); }
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 900px;
}

.hero-title {
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 24px;
}

.title-line {
    display: block;
}

.title-line.highlight {
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-desc {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 40px;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 32px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-normal);
    border: none;
}

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    box-shadow: 0 4px 20px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(99, 102, 241, 0.4);
}

.btn-outline {
    background: transparent;
    color: var(--text-primary);
    border: 2px solid var(--border-light);
}

.btn-outline:hover {
    background: var(--bg-tertiary);
    border-color: var(--accent-primary);
}

.btn-large {
    padding: 18px 40px;
    font-size: 1.1rem;
}

/* ===== Scroll Indicator ===== */
.scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: var(--text-muted);
    font-size: 0.875rem;
    animation: bounce 2s ease-in-out infinite;
}

.scroll-arrow {
    width: 24px;
    height: 24px;
    border-right: 2px solid var(--text-muted);
    border-bottom: 2px solid var(--text-muted);
    transform: rotate(45deg);
}

@keyframes bounce {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50% { transform: translateX(-50%) translateY(10px); }
}

/* ===== Section Styles ===== */
.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-tag {
    display: inline-block;
    padding: 8px 20px;
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.2);
    border-radius: var(--radius-xl);
    color: var(--accent-primary);
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 16px;
}

.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
}

/* ===== Features Section ===== */
.features {
    padding: 100px 0;
    background: var(--bg-secondary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.feature-card {
    padding: 40px 32px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    transition: all var(--transition-normal);
}

.feature-card:hover {
    transform: translateY(-8px);
    border-color: var(--accent-primary);
    box-shadow: var(--shadow-glow);
}

.feature-icon {
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--accent-gradient);
    border-radius: var(--radius-md);
    margin-bottom: 24px;
}

.feature-icon svg {
    width: 28px;
    height: 28px;
    color: white;
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ===== Stats Section ===== */
.stats {
    padding: 80px 0;
    background: var(--bg-primary);
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 40px;
}

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

.stat-number {
    font-size: 3.5rem;
    font-weight: 800;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-suffix {
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent-primary);
}

.stat-label {
    display: block;
    margin-top: 8px;
    color: var(--text-secondary);
    font-size: 1rem;
}

/* ===== CTA Section ===== */
.cta {
    padding: 100px 0;
    background: var(--bg-secondary);
}

.cta-content {
    text-align: center;
    max-width: 700px;
    margin: 0 auto;
    padding: 60px 40px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    position: relative;
    overflow: hidden;
}

.cta-content::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--accent-gradient);
}

.cta-content h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 16px;
}

.cta-content p {
    color: var(--text-secondary);
    margin-bottom: 32px;
}

/* ===== Footer ===== */
.footer {
    padding: 80px 0 0;
    background: var(--bg-primary);
    border-top: 1px solid var(--border-color);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: 60px;
    padding-bottom: 60px;
    border-bottom: 1px solid var(--border-color);
}

.footer-brand .logo {
    margin-bottom: 20px;
}

.footer-desc {
    color: var(--text-secondary);
    line-height: 1.7;
}

.footer-links h4,
.footer-contact h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 20px;
    color: var(--text-primary);
}

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

.footer-links a {
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

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

.footer-contact p {
    color: var(--text-secondary);
    margin-bottom: 12px;
    line-height: 1.6;
}

.footer-contact a:hover {
    color: var(--accent-primary);
}

.footer-bottom {
    padding: 24px 0;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        flex-direction: column;
        background: var(--bg-secondary);
        padding: 20px;
        border-bottom: 1px solid var(--border-color);
    }
    
    .nav-links.active {
        display: flex;
    }
    
    .mobile-menu-btn {
        display: flex;
    }
    
    .hero {
        padding: 100px 20px 60px;
    }
    
    .hero-desc {
        font-size: 1.1rem;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 30px;
    }
    
    .stat-number {
        font-size: 2.5rem;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }
}

@media (max-width: 480px) {
    .hero-buttons {
        flex-direction: column;
        width: 100%;
    }
    
    .btn {
        width: 100%;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
}