:root {
    --bg-primary: #f0f4ff;
    --bg-secondary: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --accent-indigo: #6366f1;
    --accent-blue: #3b82f6;
    --accent-cyan: #06b6d4;
    --accent-pink: #ec4899;
    --accent-orange: #f97316;
    --accent-emerald: #10b981;
    --card-bg: rgba(255, 255, 255, 0.75);
    --card-border: rgba(99, 102, 241, 0.12);
    --card-hover: rgba(255, 255, 255, 0.95);
    --shadow-sm: 0 2px 8px rgba(99, 102, 241, 0.06);
    --shadow-md: 0 8px 24px rgba(99, 102, 241, 0.1);
    --shadow-lg: 0 20px 50px rgba(99, 102, 241, 0.12);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
    line-height: 1.6;
}

/* Background decoration */
.bg-decoration {
    position: fixed;
    inset: 0;
    z-index: 0;
    overflow: hidden;
    pointer-events: none;
}

.orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(90px);
    opacity: 0.5;
    animation: float 22s ease-in-out infinite;
}

.orb-1 {
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, #818cf8, transparent 70%);
    top: -150px;
    left: -100px;
}

.orb-2 {
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, #38bdf8, transparent 70%);
    top: 35%;
    right: -120px;
    animation-delay: -7s;
}

.orb-3 {
    width: 450px;
    height: 450px;
    background: radial-gradient(circle, #f0abfc, transparent 70%);
    bottom: -120px;
    left: 25%;
    animation-delay: -14s;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(50px, -50px) scale(1.1); }
    66% { transform: translate(-30px, 30px) scale(0.95); }
}

/* Navbar */
.navbar {
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    background: rgba(240, 244, 255, 0.8);
    border-bottom: 1px solid var(--card-border);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 16px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.nav-logo-icon {
    width: 34px;
    height: 34px;
}

.nav-title {
    font-size: 1.35rem;
    font-weight: 700;
    letter-spacing: 2px;
    background: linear-gradient(135deg, var(--accent-indigo), var(--accent-blue));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    gap: 32px;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.95rem;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-links a:hover {
    color: var(--accent-indigo);
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-indigo);
    border-radius: 2px;
    transition: width 0.3s ease;
}

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

/* Container */
.container {
    position: relative;
    z-index: 1;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Glass card */
.glass {
    background: var(--card-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--card-border);
    border-radius: 24px;
    box-shadow: var(--shadow-sm);
}

/* Hero */
.hero {
    text-align: center;
    padding: 90px 20px 70px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 20px;
    background: rgba(99, 102, 241, 0.08);
    border: 1px solid rgba(99, 102, 241, 0.15);
    border-radius: 100px;
    color: var(--accent-indigo);
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 28px;
    animation: fadeInDown 0.8s ease;
}

.hero-title {
    font-size: clamp(2.8rem, 8vw, 5rem);
    font-weight: 900;
    letter-spacing: -2px;
    margin-bottom: 24px;
    background: linear-gradient(135deg, var(--accent-indigo) 0%, var(--accent-blue) 50%, var(--accent-cyan) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: fadeInUp 0.8s ease 0.1s both;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    font-weight: 400;
    max-width: 580px;
    margin: 0 auto 40px;
    animation: fadeInUp 0.8s ease 0.2s both;
}

.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 0.8s ease 0.3s both;
}

.btn-primary, .btn-secondary {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 34px;
    border-radius: 100px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: all 0.3s ease;
    font-family: inherit;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-indigo), var(--accent-blue));
    color: white;
    box-shadow: 0 8px 24px rgba(99, 102, 241, 0.35);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 14px 36px rgba(99, 102, 241, 0.45);
}

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--card-border);
    box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
    border-color: var(--accent-indigo);
    color: var(--accent-indigo);
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeInDown {
    from { opacity: 0; transform: translateY(-20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Section headers */
.section-header {
    text-align: center;
    margin-bottom: 50px;
}

.section-tag {
    display: inline-block;
    padding: 6px 18px;
    background: rgba(99, 102, 241, 0.1);
    color: var(--accent-indigo);
    border-radius: 100px;
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 1.5px;
    margin-bottom: 16px;
    text-transform: uppercase;
}

.section-title {
    font-size: 2.3rem;
    font-weight: 800;
    margin-bottom: 12px;
    letter-spacing: -1px;
    color: var(--text-primary);
}

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

/* Features */
.features-section {
    padding: 70px 0;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 24px;
}

.feature-card {
    padding: 36px 28px;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.feature-card:hover {
    transform: translateY(-8px);
    background: var(--card-hover);
    border-color: rgba(99, 102, 241, 0.25);
    box-shadow: var(--shadow-lg);
}

.feature-icon-wrap {
    width: 60px;
    height: 60px;
    border-radius: 18px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 24px;
}

.feature-icon-wrap svg {
    width: 30px;
    height: 30px;
}

.icon-indigo {
    background: linear-gradient(135deg, #6366f1, #818cf8);
    color: white;
    box-shadow: 0 8px 20px rgba(99, 102, 241, 0.3);
}

.icon-blue {
    background: linear-gradient(135deg, #3b82f6, #60a5fa);
    color: white;
    box-shadow: 0 8px 20px rgba(59, 130, 246, 0.3);
}

.icon-pink {
    background: linear-gradient(135deg, #ec4899, #f472b6);
    color: white;
    box-shadow: 0 8px 20px rgba(236, 72, 153, 0.3);
}

.icon-emerald {
    background: linear-gradient(135deg, #10b981, #34d399);
    color: white;
    box-shadow: 0 8px 20px rgba(16, 185, 129, 0.3);
}

.feature-card h3 {
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--text-primary);
}

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

/* Upload */
.upload-section {
    padding: 70px 0;
}

.upload-area {
    max-width: 640px;
    margin: 0 auto;
    padding: 56px 40px;
    text-align: center;
    border: 2px dashed rgba(99, 102, 241, 0.25);
    cursor: pointer;
    transition: all 0.3s ease;
}

.upload-area:hover, .upload-area.dragover {
    border-color: var(--accent-indigo);
    background: rgba(99, 102, 241, 0.04);
}

.upload-icon-wrap {
    width: 76px;
    height: 76px;
    margin: 0 auto 24px;
    border-radius: 22px;
    background: linear-gradient(135deg, var(--accent-indigo), var(--accent-blue), var(--accent-cyan));
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    box-shadow: 0 10px 30px rgba(99, 102, 241, 0.35);
}

.upload-icon-wrap svg {
    width: 34px;
    height: 34px;
}

.upload-area h3 {
    font-size: 1.4rem;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--text-primary);
}

.upload-area p {
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.upload-link {
    color: var(--accent-indigo);
    font-weight: 600;
    cursor: pointer;
}

.upload-formats {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
}

.upload-formats span {
    padding: 6px 16px;
    background: rgba(99, 102, 241, 0.06);
    border: 1px solid rgba(99, 102, 241, 0.12);
    border-radius: 100px;
    font-size: 0.8rem;
    color: var(--text-secondary);
    font-weight: 500;
}

/* Stats */
.stats-section {
    padding: 70px 0;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 24px;
}

.stat-card {
    padding: 36px 24px;
    text-align: center;
    transition: all 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

.stat-value {
    font-size: 3rem;
    font-weight: 900;
    background: linear-gradient(135deg, var(--accent-indigo), var(--accent-blue));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 8px;
    letter-spacing: -2px;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 500;
}

/* Footer */
.footer {
    padding: 50px 0 40px;
    margin-top: 60px;
    border-top: 1px solid var(--card-border);
}

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

.footer-brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 16px;
}

.footer-logo-icon {
    width: 30px;
    height: 30px;
}

.footer-brand span {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text-primary);
}

.copyright {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 20px;
    font-weight: 400;
}

.beian-info {
    display: flex;
    justify-content: center;
}

.beian-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 18px;
    background: var(--bg-secondary);
    border: 1px solid var(--card-border);
    border-radius: 100px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.85rem;
    font-weight: 500;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-sm);
}

.beian-link:hover {
    color: var(--accent-indigo);
    border-color: var(--accent-indigo);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* Reveal animation */
.reveal {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

    .hero {
        padding: 60px 20px 50px;
    }

    .hero-subtitle {
        font-size: 1.05rem;
    }

    .section-title {
        font-size: 1.7rem;
    }

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

    .feature-card,
    .stat-card {
        padding: 28px 20px;
    }

    .stat-value {
        font-size: 2.2rem;
    }

    .upload-area {
        padding: 40px 24px;
    }

    .upload-formats {
        gap: 8px;
    }
}

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

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-actions {
        flex-direction: column;
        width: 100%;
    }

    .btn-primary, .btn-secondary {
        width: 100%;
        justify-content: center;
    }
}