/* ===== CSS Variables ===== */
:root {
    --primary: #6366f1;
    --primary-light: #818cf8;
    --primary-dark: #4f46e5;
    --accent: #22d3ee;
    --accent-light: #67e8f9;
    --bg-dark: #0a0a0f;
    --bg-darker: #050508;
    --bg-card: #12121a;
    --bg-card-hover: #1a1a25;
    --text-primary: #ffffff;
    --text-secondary: #a1a1aa;
    --text-muted: #71717a;
    --border-color: #27272a;
    --gradient-primary: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    --gradient-dark: linear-gradient(180deg, var(--bg-dark) 0%, var(--bg-darker) 100%);
    --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, 0.3);
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    background: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

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

ul {
    list-style: none;
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 32px;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-normal);
    border: none;
    gap: 8px;
}

.btn-primary {
    background: var(--gradient-primary);
    color: var(--text-primary);
    box-shadow: var(--shadow-glow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 0 60px rgba(99, 102, 241, 0.5);
}

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

.btn-outline:hover {
    border-color: var(--primary);
    background: rgba(99, 102, 241, 0.1);
}

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

/* ===== Navigation ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 20px 0;
    transition: all var(--transition-normal);
    background: transparent;
}

.navbar.scrolled {
    background: rgba(10, 10, 15, 0.95);
    backdrop-filter: blur(20px);
    padding: 15px 0;
    box-shadow: var(--shadow-md);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.5rem;
    font-weight: 700;
}

.logo-icon {
    width: 45px;
    height: 45px;
    background: var(--gradient-primary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
}

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

.nav-links {
    display: flex;
    gap: 40px;
}

.nav-links a {
    color: var(--text-secondary);
    font-weight: 500;
    position: relative;
    padding: 8px 0;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    transition: width var(--transition-normal);
}

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

.nav-links a:hover::after,
.nav-links a.active::after {
    width: 100%;
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 15px;
}

.lang-switch {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 16px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

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

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.5rem;
    cursor: pointer;
}

/* ===== Hero Section ===== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    padding: 100px 20px;
}

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

.particles {
    position: absolute;
    inset: 0;
}

.particle {
    position: absolute;
    width: 4px;
    height: 4px;
    background: var(--primary);
    border-radius: 50%;
    opacity: 0.5;
    animation: float 15s infinite;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0) translateX(0);
        opacity: 0.5;
    }
    50% {
        transform: translateY(-100px) translateX(50px);
        opacity: 0.2;
    }
}

.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: 50px 50px;
}

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

.hero-title {
    font-size: clamp(3rem, 8vw, 6rem);
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 30px;
}

.hero-title .line1 {
    display: block;
    color: var(--text-primary);
}

.hero-title .line2 {
    display: block;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-title .line3 {
    display: block;
    color: var(--accent);
}

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

.hero-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

.hero-scroll {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    color: var(--text-muted);
    font-size: 0.875rem;
    animation: bounce 2s infinite;
}

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

/* ===== Section Styles ===== */
section {
    padding: 100px 0;
}

.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, 0.3);
    border-radius: 50px;
    color: var(--primary-light);
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 20px;
}

.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ===== Features Section ===== */
.features {
    background: var(--bg-darker);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 40px 30px;
    text-align: center;
    transition: all var(--transition-normal);
}

.feature-card:hover {
    transform: translateY(-10px);
    border-color: var(--primary);
    box-shadow: var(--shadow-glow);
}

.feature-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 25px;
    background: var(--gradient-primary);
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: var(--text-primary);
}

.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: 15px;
}

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

/* ===== Stats Section ===== */
.stats {
    background: var(--gradient-primary);
    padding: 80px 0;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    text-align: center;
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.stat-number {
    font-size: 3.5rem;
    font-weight: 800;
    display: inline;
}

.stat-suffix {
    font-size: 2rem;
    font-weight: 700;
}

.stat-label {
    font-size: 1rem;
    opacity: 0.9;
    margin-top: 10px;
}

/* ===== Services Preview ===== */
.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
}

.service-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 40px;
    position: relative;
    overflow: hidden;
    transition: all var(--transition-normal);
}

.service-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--gradient-primary);
    transform: scaleX(0);
    transition: transform var(--transition-normal);
}

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

.service-card:hover::before {
    transform: scaleX(1);
}

.service-number {
    font-size: 4rem;
    font-weight: 800;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.2) 0%, rgba(34, 211, 238, 0.2) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    position: absolute;
    top: 20px;
    right: 30px;
}

.service-card h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
}

.service-card p {
    color: var(--text-secondary);
    margin-bottom: 25px;
}

.service-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--primary-light);
    font-weight: 600;
}

.service-link:hover {
    color: var(--accent);
}

.service-link i {
    transition: transform var(--transition-fast);
}

.service-link:hover i {
    transform: translateX(5px);
}

/* ===== CTA Section ===== */
.cta {
    background: var(--bg-darker);
    text-align: center;
}

.cta-content {
    max-width: 700px;
    margin: 0 auto;
    padding: 80px 40px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 24px;
    position: relative;
    overflow: hidden;
}

.cta-content::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.1) 0%, transparent 50%);
    animation: rotate 20s linear infinite;
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.cta-content h2 {
    font-size: 2.5rem;
    margin-bottom: 20px;
    position: relative;
}

.cta-content p {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 30px;
    position: relative;
}

.cta-content .btn {
    position: relative;
}

/* ===== Footer ===== */
.footer {
    background: var(--bg-darker);
    padding: 80px 0 30px;
    border-top: 1px solid var(--border-color);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: 50px;
    margin-bottom: 60px;
}

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

.footer-desc {
    color: var(--text-secondary);
    margin-bottom: 25px;
    line-height: 1.8;
}

.social-links {
    display: flex;
    gap: 15px;
}

.social-links a {
    width: 45px;
    height: 45px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.social-links a:hover {
    background: var(--primary);
    border-color: var(--primary);
    color: var(--text-primary);
    transform: translateY(-3px);
}

.footer-links h4,
.footer-contact h4 {
    font-size: 1.1rem;
    margin-bottom: 25px;
    color: var(--text-primary);
}

.footer-links ul {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

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

.footer-links a:hover {
    color: var(--primary-light);
    padding-left: 5px;
}

.footer-contact ul {
    display: flex;
    flex-direction: column;
    gap: 18px;
}

.footer-contact li {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    color: var(--text-secondary);
}

.footer-contact i {
    color: var(--primary-light);
    margin-top: 4px;
    width: 16px;
}

.footer-contact a {
    color: var(--text-secondary);
}

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

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 30px;
    border-top: 1px solid var(--border-color);
}

.copyright {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.footer-legal {
    display: flex;
    gap: 30px;
}

.footer-legal a {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.footer-legal a:hover {
    color: var(--primary-light);
}

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

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: rgba(10, 10, 15, 0.98);
        flex-direction: column;
        padding: 20px;
        gap: 0;
        border-top: 1px solid var(--border-color);
    }

    .nav-links.active {
        display: flex;
    }

    .nav-links li {
        border-bottom: 1px solid var(--border-color);
    }

    .nav-links a {
        display: block;
        padding: 15px 0;
    }

    .mobile-menu-btn {
        display: block;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .services-grid {
        grid-template-columns: 1fr;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .footer-bottom {
        flex-direction: column;
        gap: 20px;
        text-align: center;
    }
}