/* ========================================
   Base & Reset
   ======================================== */

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

:root {
    --primary: #4f46e5;
    --primary-dark: #3730a3;
    --primary-light: #818cf8;
    --accent: #06b6d4;
    --bg: #ffffff;
    --bg-alt: #f8fafc;
    --bg-dark: #0f172a;
    --text: #1e293b;
    --text-secondary: #64748b;
    --text-light: #94a3b8;
    --border: #e2e8f0;
    --radius: 12px;
    --radius-lg: 20px;
    --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.07), 0 2px 4px -2px rgba(0,0,0,0.05);
    --shadow-lg: 0 10px 25px -3px rgba(0,0,0,0.08), 0 4px 6px -4px rgba(0,0,0,0.04);
    --shadow-xl: 0 20px 50px -12px rgba(0,0,0,0.15);
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC',
                 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.6;
    overflow-x: hidden;
}

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

a {
    text-decoration: none;
    color: inherit;
}

/* ========================================
   Buttons
   ======================================== */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 24px;
    border-radius: 8px;
    font-size: 0.95rem;
    font-weight: 500;
    border: none;
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
}

.btn-lg {
    padding: 14px 32px;
    font-size: 1.05rem;
    border-radius: 10px;
}

.btn-primary {
    background: var(--primary);
    color: #fff;
    box-shadow: 0 2px 8px rgba(79, 70, 229, 0.3);
}

.btn-primary:hover {
    background: var(--primary-dark);
    box-shadow: 0 4px 16px rgba(79, 70, 229, 0.4);
    transform: translateY(-1px);
}

.btn-outline {
    background: transparent;
    color: var(--primary);
    border: 1.5px solid var(--primary);
}

.btn-outline:hover {
    background: var(--primary);
    color: #fff;
    transform: translateY(-1px);
}

.btn-outline-light {
    background: transparent;
    color: #fff;
    border: 1.5px solid rgba(255,255,255,0.5);
}

.btn-outline-light:hover {
    background: rgba(255,255,255,0.1);
    border-color: #fff;
    transform: translateY(-1px);
}

.btn-nav {
    background: var(--primary);
    color: #fff;
    padding: 8px 20px;
    font-size: 0.9rem;
}

.btn-nav:hover {
    background: var(--primary-dark);
}

/* ========================================
   Navigation
   ======================================== */

.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid transparent;
    transition: var(--transition);
}

.nav.scrolled {
    border-bottom-color: var(--border);
    box-shadow: var(--shadow);
}

.nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 1.1rem;
}

.nav-logo {
    font-size: 1.5rem;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 8px;
    list-style: none;
}

.nav-links a {
    padding: 8px 16px;
    border-radius: 8px;
    font-size: 0.9rem;
    color: var(--text-secondary);
    transition: var(--transition);
}

.nav-links a:hover {
    color: var(--primary);
    background: rgba(79, 70, 229, 0.06);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.nav-toggle span {
    width: 22px;
    height: 2px;
    background: var(--text);
    border-radius: 2px;
    transition: var(--transition);
}

/* ========================================
   Hero
   ======================================== */

.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 120px 0 80px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse 80% 60% at 50% 0%, rgba(79, 70, 229, 0.08) 0%, transparent 60%),
        radial-gradient(ellipse 60% 50% at 80% 20%, rgba(6, 182, 212, 0.06) 0%, transparent 50%),
        radial-gradient(ellipse 40% 40% at 20% 80%, rgba(79, 70, 229, 0.04) 0%, transparent 50%);
    z-index: -1;
}

.hero-content {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.hero-badge {
    display: inline-block;
    padding: 6px 18px;
    border-radius: 30px;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--primary);
    background: rgba(79, 70, 229, 0.08);
    border: 1px solid rgba(79, 70, 229, 0.15);
    margin-bottom: 28px;
    letter-spacing: 1px;
}

.hero h1 {
    font-size: clamp(2.4rem, 6vw, 3.8rem);
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 20px;
    background: linear-gradient(135deg, var(--text) 0%, var(--primary-dark) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-desc {
    font-size: 1.15rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 36px;
}

.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 64px;
}

.hero-stats {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 40px;
    flex-wrap: wrap;
}

.stat {
    text-align: center;
}

.stat-num {
    font-size: 2.2rem;
    font-weight: 800;
    color: var(--primary);
    font-variant-numeric: tabular-nums;
}

.stat-unit {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--primary);
}

.stat-label {
    display: block;
    font-size: 0.85rem;
    color: var(--text-light);
    margin-top: 4px;
}

.stat-divider {
    width: 1px;
    height: 40px;
    background: var(--border);
}

/* ========================================
   Sections
   ======================================== */

.section {
    padding: 100px 0;
}

.section-alt {
    background: var(--bg-alt);
}

.section-header {
    text-align: center;
    max-width: 600px;
    margin: 0 auto 60px;
}

.section-tag {
    display: inline-block;
    padding: 4px 14px;
    border-radius: 6px;
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--primary);
    background: rgba(79, 70, 229, 0.08);
    margin-bottom: 16px;
    letter-spacing: 1px;
}

.section-header h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.section-header p {
    font-size: 1.05rem;
    color: var(--text-secondary);
}

/* ========================================
   Features Grid
   ======================================== */

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

.feature-card {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 36px 30px;
    transition: var(--transition);
}

.feature-card:hover {
    border-color: rgba(79, 70, 229, 0.2);
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.feature-icon {
    font-size: 2.4rem;
    margin-bottom: 18px;
    display: inline-block;
}

.feature-card h3 {
    font-size: 1.15rem;
    font-weight: 650;
    margin-bottom: 10px;
}

.feature-card p {
    font-size: 0.92rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ========================================
   Steps
   ======================================== */

.steps {
    max-width: 700px;
    margin: 0 auto;
}

.step {
    display: flex;
    gap: 28px;
    align-items: flex-start;
}

.step-number {
    flex-shrink: 0;
    width: 64px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 16px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: #fff;
    font-size: 1.3rem;
    font-weight: 800;
    box-shadow: 0 4px 12px rgba(79, 70, 229, 0.25);
}

.step-content h3 {
    font-size: 1.2rem;
    font-weight: 650;
    margin-bottom: 8px;
    margin-top: 4px;
}

.step-content p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.step-connector {
    width: 2px;
    height: 40px;
    background: linear-gradient(to bottom, var(--primary-light), rgba(79, 70, 229, 0.15));
    margin-left: 31px;
}

/* ========================================
   Tech Grid
   ======================================== */

.tech-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.tech-card {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 28px 24px;
    text-align: center;
    transition: var(--transition);
}

.tech-card:hover {
    border-color: rgba(79, 70, 229, 0.2);
    box-shadow: var(--shadow-md);
}

.tech-label {
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--primary);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 8px;
}

.tech-value {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 6px;
}

.tech-desc {
    font-size: 0.85rem;
    color: var(--text-light);
}

/* ========================================
   CTA Section
   ======================================== */

.cta-section {
    padding: 80px 0 100px;
}

.cta-card {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 60%, #1e1b4b 100%);
    border-radius: var(--radius-lg);
    padding: 64px 48px;
    text-align: center;
    color: #fff;
    position: relative;
    overflow: hidden;
}

.cta-card::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(129, 140, 248, 0.2) 0%, transparent 60%);
    pointer-events: none;
}

.cta-card h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 12px;
    position: relative;
}

.cta-card p {
    font-size: 1.05rem;
    opacity: 0.85;
    margin-bottom: 32px;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
    position: relative;
}

.cta-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 32px;
    position: relative;
}

.cta-actions .btn-primary {
    background: #fff;
    color: var(--primary-dark);
    box-shadow: 0 2px 12px rgba(0,0,0,0.15);
}

.cta-actions .btn-primary:hover {
    background: #f1f5f9;
    box-shadow: 0 4px 20px rgba(0,0,0,0.2);
}

.cta-contact {
    display: flex;
    gap: 32px;
    justify-content: center;
    font-size: 0.9rem;
    opacity: 0.7;
    position: relative;
}

/* ========================================
   Footer
   ======================================== */

.footer {
    background: var(--bg-dark);
    color: rgba(255,255,255,0.6);
    padding: 40px 0;
}

.footer-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 20px;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 8px;
    color: #fff;
    font-weight: 600;
    font-size: 0.95rem;
}

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

.footer-links a {
    font-size: 0.88rem;
    transition: var(--transition);
}

.footer-links a:hover {
    color: #fff;
}

.footer-copy {
    font-size: 0.82rem;
}

/* ========================================
   Animations
   ======================================== */

.fade-up {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-up.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ========================================
   Responsive
   ======================================== */

@media (max-width: 1024px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .tech-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: rgba(255,255,255,0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 16px 24px;
        border-bottom: 1px solid var(--border);
        box-shadow: var(--shadow-lg);
    }

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

    .nav-links a {
        width: 100%;
        padding: 12px 16px;
    }

    .hero {
        padding: 100px 0 60px;
        min-height: auto;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .hero-desc {
        font-size: 1rem;
    }

    .hero-stats {
        gap: 24px;
    }

    .stat-num {
        font-size: 1.6rem;
    }

    .stat-divider {
        height: 30px;
    }

    .section {
        padding: 60px 0;
    }

    .section-header {
        margin-bottom: 40px;
    }

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

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

    .step {
        gap: 18px;
    }

    .step-number {
        width: 48px;
        height: 48px;
        font-size: 1rem;
        border-radius: 12px;
    }

    .step-connector {
        margin-left: 23px;
        height: 28px;
    }

    .cta-card {
        padding: 40px 24px;
    }

    .cta-card h2 {
        font-size: 1.5rem;
    }

    .cta-contact {
        flex-direction: column;
        gap: 8px;
    }

    .footer-inner {
        flex-direction: column;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .tech-grid {
        grid-template-columns: 1fr;
    }

    .hero-stats {
        flex-direction: column;
        gap: 16px;
    }

    .stat-divider {
        width: 40px;
        height: 1px;
    }
}