:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --text-color: #1f2937;
    --light-bg: #f3f4f6;
    --white: #ffffff;
}

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

body {
    font-family: 'Noto Sans SC', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
}

/* Header & Navigation */
header {
    background-color: var(--white);
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

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: 700;
    color: var(--primary-color);
}

.nav-links a {
    text-decoration: none;
    color: var(--text-color);
    margin-left: 2rem;
    font-weight: 500;
    transition: color 0.3s ease;
}

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

.admin-btn {
    background-color: var(--primary-color);
    color: var(--white) !important;
    padding: 0.5rem 1rem;
    border-radius: 4px;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
    padding: 8rem 2rem 4rem;
    text-align: center;
}

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

.hero h1 {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
}

.hero-text {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    color: #4b5563;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 2rem;
}

.hero-buttons .download-btn,
.hero-buttons .admin-btn {
    min-width: 160px;
    text-align: center;
}

/* Features Section */
.features {
    padding: 4rem 2rem;
    background-color: var(--white);
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.feature-card {
    text-align: center;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
}

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

.feature-card img {
    width: 100%;
    border-radius: 4px;
    margin-bottom: 1rem;
}

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

/* Stats Section */
.stats {
    background-color: var(--light-bg);
    padding: 4rem 2rem;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    text-align: center;
}

.stat-item h2 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

/* Download Section */
.download {
    padding: 4rem 2rem;
    text-align: center;
    background-color: var(--white);
}

.download h2 {
    margin-bottom: 2rem;
}

.download-btn {
    display: inline-block;
    background-color: var(--primary-color);
    color: var(--white);
    padding: 1rem 2rem;
    border-radius: 4px;
    text-decoration: none;
    font-weight: 500;
    transition: background-color 0.3s ease;
}

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

/* Footer */
footer {
    background-color: var(--light-bg);
    padding: 2rem;
    text-align: center;
    color: #6b7280;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .hero-text {
        font-size: 1rem;
    }
    
    .features {
        grid-template-columns: 1fr;
    }

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

    .hero-buttons .download-btn,
    .hero-buttons .admin-btn {
        width: 100%;
        max-width: 300px;
    }
}