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

:root {
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary-color: #64748b;
    --accent-color: #06b6d4;
    --text-color: #1e293b;
    --text-light: #64748b;
    --bg-color: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #e2e8f0;
    --border-color: #e2e8f0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --border-radius: 8px;
    --transition: all 0.3s ease;
}

[data-theme="dark"] {
    --primary-color: #3b82f6;
    --primary-dark: #2563eb;
    --secondary-color: #94a3b8;
    --accent-color: #06b6d4;
    --text-color: #f1f5f9;
    --text-light: #cbd5e1;
    --bg-color: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --border-color: #334155;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    transition: var(--transition);
}

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

/* Navigation */
.navbar {
    background: var(--bg-color);
    box-shadow: var(--shadow);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
}

.nav-menu {
    display: flex;
    gap: 30px;
}

.nav-link {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: var(--transition);
}

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

.nav-actions {
    display: flex;
    align-items: center;
    gap: 15px;
}

.theme-toggle {
    background: none;
    border: none;
    color: var(--text-color);
    font-size: 1.2rem;
    cursor: pointer;
    padding: 8px;
    border-radius: 50%;
    transition: var(--transition);
}

.theme-toggle:hover {
    background: var(--bg-tertiary);
}

.mobile-menu-btn {
    display: none;
    font-size: 1.5rem;
    cursor: pointer;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: white;
    padding: 120px 20px 80px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: 80vh;
}

.hero-content {
    flex: 1;
    max-width: 600px;
}

.hero-content h1 {
    font-size: 3rem;
    margin-bottom: 10px;
    font-weight: 700;
}

.hero-content h2 {
    font-size: 1.8rem;
    margin-bottom: 20px;
    font-weight: 400;
}

.hero-content p {
    font-size: 1.1rem;
    margin-bottom: 30px;
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
}

.hero-image {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-image i {
    font-size: 15rem;
    opacity: 0.8;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    border: none;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    font-size: 1rem;
}

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

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

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

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

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

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

/* Sections */
.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 50px;
    color: var(--text-color);
}

.features {
    padding: 80px 0;
    background: var(--bg-secondary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.feature-card {
    background: var(--bg-color);
    padding: 40px 30px;
    border-radius: var(--border-radius);
    text-align: center;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

.feature-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    color: white;
    font-size: 2rem;
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
    color: var(--text-color);
}

.feature-card p {
    color: var(--text-light);
    line-height: 1.6;
}

/* Materials Section */
.materials {
    padding: 80px 0;
}

.materials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
    margin-bottom: 40px;
}

.material-card {
    background: var(--bg-color);
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

.material-header {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: white;
    padding: 20px;
}

.material-header h3 {
    font-size: 1.3rem;
    margin-bottom: 5px;
}

.material-body {
    padding: 20px;
}

.material-body p {
    color: var(--text-light);
    margin-bottom: 15px;
}

.material-meta {
    display: flex;
    justify-content: space-between;
    color: var(--text-light);
    font-size: 0.9rem;
}

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

/* Footer */
.footer {
    background: var(--bg-secondary);
    padding: 50px 0 20px;
    margin-top: 50px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 30px;
}

.footer-section h3 {
    margin-bottom: 20px;
    color: var(--text-color);
}

.footer-section a {
    display: block;
    color: var(--text-light);
    text-decoration: none;
    margin-bottom: 10px;
    transition: var(--transition);
}

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

.footer-section p {
    color: var(--text-light);
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
    color: var(--text-light);
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }
    
    .mobile-menu-btn {
        display: block;
    }
    
    .hero {
        flex-direction: column;
        text-align: center;
        padding: 100px 20px 60px;
    }
    
    .hero-content h1 {
        font-size: 2.2rem;
    }
    
    .hero-content h2 {
        font-size: 1.4rem;
    }
    
    .hero-image i {
        font-size: 8rem;
        margin-top: 30px;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .features-grid,
    .materials-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
}