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

:root {
    --primary-color: #6366f1;
    --secondary-color: #8b5cf6;
    --accent-color: #ec4899;
    --text-color: #1f2937;
    --text-light: #6b7280;
    --bg-light: #f9fafb;
    --border-color: #e5e7eb;
    --shadow: 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);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Microsoft YaHei', sans-serif;
    color: var(--text-color);
    line-height: 1.6;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

/* Header & Navigation */
header {
    background: rgba(255, 255, 255, 0.98);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
}

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

.nav-links a {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

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

/* Main Content */
main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 4rem 2rem;
    background: white;
    border-radius: 1rem;
    box-shadow: var(--shadow-lg);
    margin-bottom: 3rem;
}

.hero h1 {
    font-size: 3.5rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 1rem;
}

.subtitle {
    font-size: 1.5rem;
    color: var(--text-light);
    margin-bottom: 1rem;
}

.description {
    font-size: 1.1rem;
    color: var(--text-color);
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* Buttons */
.download-btn, .download-btn-large {
    display: inline-block;
    padding: 1rem 2.5rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    text-decoration: none;
    border-radius: 0.5rem;
    font-weight: 600;
    font-size: 1.1rem;
    transition: transform 0.2s, box-shadow 0.2s;
    box-shadow: var(--shadow);
}

.download-btn:hover, .download-btn-large:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.download-btn-large {
    padding: 1.25rem 3rem;
    font-size: 1.25rem;
}

/* Features Section */
.features {
    background: white;
    padding: 3rem 2rem;
    border-radius: 1rem;
    box-shadow: var(--shadow-lg);
    margin-bottom: 3rem;
}

.features h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--text-color);
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.feature-card {
    text-align: center;
    padding: 2rem;
    border-radius: 0.5rem;
    background: var(--bg-light);
    transition: transform 0.3s, box-shadow 0.3s;
}

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

.icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.feature-card p {
    color: var(--text-light);
}

/* About Section */
.about {
    background: white;
    padding: 3rem 2rem;
    border-radius: 1rem;
    box-shadow: var(--shadow-lg);
    margin-bottom: 3rem;
}

.about h2 {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
    color: var(--text-color);
}

.about p {
    font-size: 1.1rem;
    color: var(--text-color);
    margin-bottom: 1rem;
    line-height: 1.8;
}

/* Download Section */
.download-section {
    background: white;
    padding: 3rem 2rem;
    border-radius: 1rem;
    box-shadow: var(--shadow-lg);
    text-align: center;
    margin-bottom: 3rem;
}

.download-section h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.download-section p {
    font-size: 1.1rem;
    color: var(--text-light);
    margin-bottom: 2rem;
}

/* Footer */
footer {
    background: rgba(255, 255, 255, 0.98);
    margin-top: 4rem;
    padding: 2rem;
    box-shadow: 0 -4px 6px -1px rgba(0, 0, 0, 0.1);
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    text-align: center;
}

.footer-links {
    margin-bottom: 1rem;
}

.footer-links a {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

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

.separator {
    margin: 0 1rem;
    color: var(--border-color);
}

footer p {
    color: var(--text-light);
    font-size: 0.9rem;
}

.company-name {
    color: var(--text-light);
    font-size: 0.85rem;
    margin-top: 0.5rem;
    font-weight: 500;
}

/* Privacy & Terms Pages */
.policy-container {
    background: white;
    padding: 3rem;
    border-radius: 1rem;
    box-shadow: var(--shadow-lg);
    max-width: 900px;
    margin: 2rem auto;
}

.policy-container h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.policy-container h2 {
    font-size: 1.8rem;
    margin-top: 2rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.policy-container h3 {
    font-size: 1.3rem;
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--text-color);
}

.policy-container p {
    margin-bottom: 1rem;
    line-height: 1.8;
    color: var(--text-color);
}

.policy-container ul, .policy-container ol {
    margin-bottom: 1rem;
    margin-left: 2rem;
    line-height: 1.8;
    color: var(--text-color);
}

.policy-container li {
    margin-bottom: 0.5rem;
}

.last-updated {
    color: var(--text-light);
    font-style: italic;
    margin-bottom: 2rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    nav {
        flex-direction: column;
        gap: 1rem;
        padding: 1rem;
    }

    .nav-links {
        gap: 1rem;
    }

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

    .subtitle {
        font-size: 1.2rem;
    }

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

    .policy-container {
        padding: 2rem 1.5rem;
    }

    main {
        padding: 1rem;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 2rem;
    }

    .download-btn-large {
        padding: 1rem 2rem;
        font-size: 1rem;
    }
}