/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #6366f1;
    --secondary-color: #8b5cf6;
    --accent-color: #06b6d4;
    --text-primary: #f9fafb;
    --text-secondary: #d1d5db;
    --text-light: #9ca3af;
    --text-muted: #6b7280;
    --background: #0f0f23;
    --surface: #1a1a2e;
    --surface-light: #25253e;
    --border: #374151;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --gradient: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    --gradient-accent: linear-gradient(135deg, var(--accent-color), var(--primary-color));
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -2px rgba(0, 0, 0, 0.3);
    --border-radius: 8px;
    --border-radius-lg: 12px;
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

body {
    font-family: var(--font-family);
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--background);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: 0.5rem;
}

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

/* Layout */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

section {
    padding: 4rem 0;
}

/* Navigation */
.nav {
    background: rgba(15, 15, 35, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

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

.nav-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

.nav-subtitle {
    font-size: 0.875rem;
    color: var(--text-primary);
    font-weight: 400;
}

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

.nav-link {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    transition: color 0.2s;
}

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

/* Hero Section */
.hero {
    padding: 8rem 0 6rem;
    margin-top: 70px;
    background: linear-gradient(135deg, var(--background) 0%, var(--surface) 100%);
    text-align: center;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    line-height: 1.1;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-badges {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 3rem;
    flex-wrap: wrap;
}

.badge {
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius);
    font-size: 0.875rem;
    font-weight: 500;
}

.badge-free {
    background: rgba(16, 185, 129, 0.2);
    color: #10b981;
    border: 1px solid rgba(16, 185, 129, 0.3);
}

.badge-open {
    background: rgba(99, 102, 241, 0.2);
    color: #6366f1;
    border: 1px solid rgba(99, 102, 241, 0.3);
}

.badge-cross {
    background: rgba(245, 158, 11, 0.2);
    color: #f59e0b;
    border: 1px solid rgba(245, 158, 11, 0.3);
}

.hero-cta {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.hero-note {
    font-size: 1rem;
    color: var(--text-secondary);
    font-weight: 500;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.875rem;
    transition: all 0.2s;
    border: 1px solid transparent;
    cursor: pointer;
}

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

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

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

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

.btn-secondary:hover {
    background: var(--surface);
}

.btn-outline {
    background: transparent;
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
}

.btn-outline:hover {
    background: var(--primary-color);
    color: white;
}

.btn-download {
    background: var(--gradient-accent);
    color: white;
    font-weight: 600;
}

.btn-download:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

/* Problem Section */
.problem {
    background: var(--surface);
}

.problem-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.problem-item {
    text-align: center;
    padding: 2rem;
}

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

.problem-item h3 {
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.problem-item p {
    color: var(--text-secondary);
}

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

.section-title {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 1rem;
}

.section-subtitle {
    text-align: center;
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 3rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.feature-card {
    background: var(--surface);
    padding: 2rem;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    transition: transform 0.2s, box-shadow 0.2s;
}

.feature-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    display: block;
}

.feature-card h3 {
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.feature-card ul {
    list-style: none;
    padding: 0;
}

.feature-card li {
    padding: 0.25rem 0;
    color: var(--text-secondary);
    position: relative;
    padding-left: 1.5rem;
}

.feature-card li:before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--success);
    font-weight: bold;
}

.feature-card li strong {
    color: var(--text-primary);
}

/* Download Section */
.download {
    background: var(--surface);
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.download-card {
    background: var(--surface) !important;
    background-color: var(--surface) !important;
    padding: 2rem;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    text-align: center;
    transition: transform 0.2s, box-shadow 0.2s;
}

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

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

.download-card h3 {
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.download-card p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.download-buttons {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.download-note {
    margin-top: 3rem;
    text-align: center;
    color: var(--text-secondary);
}

.download-note p {
    margin-bottom: 0.5rem;
}

/* Use Cases */
.use-cases {
    background: var(--surface);
}

.use-cases-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.use-case {
    text-align: center;
    padding: 2rem;
}

.use-case h3 {
    margin-bottom: 1rem;
    font-size: 1.125rem;
}

.use-case p {
    color: var(--text-secondary);
}

/* About Section */
.about {
    background: var(--surface);
}

.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 4rem;
    align-items: center;
}

.about-description {
    font-size: 1.125rem;
    margin-bottom: 1.5rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.about-mission {
    background: var(--surface-light);
    padding: 2rem;
    border-radius: var(--border-radius-lg);
    margin: 2rem 0;
    border-left: 4px solid var(--primary-color);
}

.about-mission h3 {
    margin-bottom: 1rem;
}

.about-mission em {
    font-size: 1.125rem;
    color: var(--text-secondary);
}

.about-links {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.about-stats {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.stat {
    text-align: center;
    padding: 1.5rem;
    background: var(--surface-light);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow);
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    line-height: 1;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: 0.5rem;
}

/* Footer */
.footer {
    background: var(--surface-light);
    color: var(--text-primary);
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 3rem;
    margin-bottom: 2rem;
}

.footer-brand h3 {
    margin-bottom: 0.5rem;
}

.footer-brand p {
    color: var(--text-secondary);
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.footer-column h4 {
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.footer-column a {
    display: block;
    color: var(--text-secondary);
    text-decoration: none;
    padding: 0.25rem 0;
    transition: color 0.2s;
}

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

.footer-bottom {
    border-top: 1px solid var(--border);
    padding-top: 2rem;
    text-align: center;
    color: var(--text-secondary);
}

.footer-bottom p {
    margin-bottom: 0.5rem;
}

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

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

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

    .about-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .about-stats {
        flex-direction: row;
        justify-content: center;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .footer-links {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .section-title {
        font-size: 2rem;
    }

    .container {
        padding: 0 1rem;
    }
}

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

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

    .download-buttons {
        gap: 0.5rem;
    }

    .about-links {
        justify-content: center;
    }

    .about-stats {
        flex-direction: column;
    }
}

/* Smooth scrolling */
html {
    scroll-behavior: smooth;
}

/* Focus states for accessibility */
.btn:focus, .nav-link:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Animation for loading */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.fade-in {
    animation: fadeIn 0.6s ease-out;
}