:root {
    --primary: #4A90E2;
    --secondary: #50C878;
    --text: #333;
    --background: #ffffff;
    --light-gray: #f5f5f5;
    --border: #e0e0e0;
    --shadow: rgba(0, 0, 0, 0.1);
}

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

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
header {
    background: var(--background);
    box-shadow: 0 2px 4px var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary);
    text-decoration: none;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

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

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

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: white;
    padding: 6rem 20px;
    text-align: center;
}

.hero-content h1 {
    font-size: 3rem;
    margin-bottom: 0.5rem;
}

.hero-content h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    font-weight: 300;
}

.hero-description {
    font-size: 1.2rem;
    max-width: 700px;
    margin: 0 auto 2rem;
    opacity: 0.95;
}

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

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 2rem;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 600;
    transition: transform 0.2s, box-shadow 0.2s;
    border: none;
    cursor: pointer;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: 2px solid white;
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.btn-download {
    background: var(--primary);
    color: white;
    margin-top: 1rem;
}

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

/* Features Section */
.features {
    padding: 4rem 20px;
    background: var(--light-gray);
}

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

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

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px var(--shadow);
    transition: transform 0.3s, box-shadow 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 4px 16px var(--shadow);
}

.feature-card h3 {
    color: var(--primary);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

/* Tech Stack Section */
.tech-stack {
    padding: 4rem 20px;
    text-align: center;
}

.tech-stack h2 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
}

.tech-items {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
}

.tech-badge {
    background: var(--primary);
    color: white;
    padding: 0.5rem 1.5rem;
    border-radius: 20px;
    font-weight: 500;
}

/* Stats Section */
.stats {
    padding: 4rem 20px;
    background: var(--light-gray);
}

.stats h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
}

.stat-card {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    text-align: center;
    box-shadow: 0 2px 8px var(--shadow);
}

.stat-number {
    font-size: 3rem;
    font-weight: bold;
    color: var(--primary);
    margin-bottom: 0.5rem;
}

.stat-label {
    color: var(--text);
    font-size: 1rem;
}

/* Documentation Page */
.documentation-page {
    padding: 2rem 20px 4rem;
}

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

.welcome-text {
    font-size: 1.1rem;
    margin-bottom: 3rem;
    color: #666;
    max-width: 800px;
}

.documentation-list {
    display: flex;
    flex-direction: column;
    gap: 3rem;
}

.document-item {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px var(--shadow);
}

.document-item h2 {
    color: var(--primary);
    margin-bottom: 0.5rem;
    font-size: 1.8rem;
}

.document-description {
    color: #666;
    margin-bottom: 1.5rem;
    font-size: 1rem;
}

.pdf-container {
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
    margin-bottom: 1rem;
    box-shadow: 0 2px 4px var(--shadow);
}

.return-home {
    text-align: center;
    margin-top: 3rem;
}

/* Single Page (About, etc.) */
.single-page {
    padding: 2rem 20px 4rem;
}

.single-page article {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px var(--shadow);
    max-width: 900px;
    margin: 0 auto;
}

.single-page h1 {
    font-size: 2.5rem;
    color: var(--primary);
    margin-bottom: 1.5rem;
}

.single-page .content {
    line-height: 1.8;
    color: var(--text);
}

.single-page .content h2 {
    color: var(--primary);
    margin-top: 2rem;
    margin-bottom: 1rem;
    font-size: 1.8rem;
}

.single-page .content h3 {
    color: var(--text);
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
    font-size: 1.4rem;
}

.single-page .content ul,
.single-page .content ol {
    margin-left: 2rem;
    margin-bottom: 1rem;
}

.single-page .content li {
    margin-bottom: 0.5rem;
}

.single-page .content a {
    color: var(--primary);
    text-decoration: none;
}

.single-page .content a:hover {
    text-decoration: underline;
}

.single-page .content strong {
    color: var(--text);
    font-weight: 600;
}

/* Footer */
footer {
    background: var(--text);
    color: white;
    padding: 2rem 20px;
    text-align: center;
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
}

.footer-container a {
    color: var(--secondary);
    text-decoration: none;
}

.footer-container a:hover {
    text-decoration: underline;
}

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

    .nav-menu {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }

    .hero-content h1 {
        font-size: 2rem;
    }

    .hero-content h2 {
        font-size: 1.5rem;
    }

    .hero-description {
        font-size: 1rem;
    }

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

    .btn {
        width: 100%;
        max-width: 300px;
    }

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

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .document-item {
        padding: 1.5rem;
    }

    .pdf-container iframe {
        height: 400px !important;
    }

    .single-page article {
        padding: 1.5rem;
    }

    .single-page h1 {
        font-size: 2rem;
    }

    .single-page .content h2 {
        font-size: 1.5rem;
    }
}