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

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --bg: #ffffff;
    --bg-alt: #f8fafc;
    --bg-card: #ffffff;
    --text: #1e293b;
    --text-muted: #64748b;
    --border: #e2e8f0;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    z-index: 100;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
}

.nav a {
    color: var(--text-muted);
    text-decoration: none;
    margin-left: 30px;
    transition: color 0.2s;
}

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

/* Hero */
.hero {
    padding: 140px 0 80px;
    text-align: center;
    background: var(--bg-alt);
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 20px;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-muted);
    margin-bottom: 40px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.2s;
    cursor: pointer;
    border: none;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

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

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

.btn-large {
    padding: 16px 40px;
    font-size: 1.1rem;
}

/* Features */
.features {
    padding: 80px 0;
}

.features h2 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 50px;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 24px;
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 30px;
    text-align: center;
    transition: transform 0.2s, box-shadow 0.2s;
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.feature-card h3 {
    margin-bottom: 12px;
    font-size: 1.2rem;
}

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

/* Download */
.download {
    padding: 80px 0;
    background: var(--bg-alt);
}

.download h2 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 10px;
}

.download > .container > p {
    text-align: center;
    color: var(--text-muted);
    margin-bottom: 40px;
}

.download-card {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 30px 40px;
    max-width: 600px;
    margin: 0 auto;
}

.download-info h3 {
    font-size: 1.3rem;
    margin-bottom: 4px;
}

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

.download-size {
    margin-top: 4px;
}

/* Videos */
.videos {
    padding: 80px 0;
}

.videos h2 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 10px;
}

.videos > .container > p {
    text-align: center;
    color: var(--text-muted);
    margin-bottom: 30px;
}

.videos-cta {
    text-align: center;
}

/* Contact */
.contact {
    padding: 80px 0;
    background: var(--bg-alt);
}

.contact h2 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 30px;
}

.contact-info {
    text-align: center;
    font-size: 1.1rem;
}

.contact-info a {
    color: var(--primary);
    text-decoration: none;
}

.contact-info a:hover {
    text-decoration: underline;
}

/* Footer */
.footer {
    padding: 30px 0;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.9rem;
    border-top: 1px solid var(--border);
}

/* Responsive */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2rem;
    }

    .nav {
        display: none;
    }

    .download-card {
        flex-direction: column;
        text-align: center;
        gap: 20px;
    }
}