:root {
    --primary-color: #0F4C81;
    --secondary-color: #FFFFFF;
    --accent-color-green: #34C759;
    --accent-color-orange: #FFA500;
    --gray-light: #E5E5EA;
    --gradient-bg: linear-gradient(135deg, #0F4C81, #2B85D8);
    --font-primary: 'Roboto', sans-serif;
    --font-title: 'Montserrat', sans-serif;
}

body {
    margin: 0;
    padding: 0;
    font-family: var(--font-primary);
    background: var(--gradient-bg);
    color: var(--secondary-color);
    line-height: 1.6;
    letter-spacing: 0.5px;
}

header {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(15, 76, 129, 0.9);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    z-index: 1000;
}

header nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
}

header nav .logo {
    font-family: var(--font-title);
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--accent-color-green);
}

header nav ul {
    list-style: none;
    display: flex;
    gap: 1.5rem;
}

header nav ul li a {
    text-decoration: none;
    color: var(--secondary-color);
    font-weight: 500;
    transition: color 0.3s ease;
}

header nav ul li a:hover {
    color: var(--accent-color-orange);
}

.hero {
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    color: var(--secondary-color);
    padding: 2rem;
    background: url('https://images.gptkong.com/demo/sample1.png') no-repeat center/cover, var(--gradient-bg);
}

.hero h1 {
    font-family: var(--font-title);
    font-size: 3rem;
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.2rem;
    max-width: 600px;
    margin: 0 auto 2rem;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    padding: 4rem 2rem;
    background: var(--secondary-color);
    color: var(--primary-color);
}

.feature-card {
    background: var(--gray-light);
    border-radius: 10px;
    padding: 2rem;
    text-align: center;
    transition: transform 0.3s ease;
}

.feature-card:hover {
    transform: scale(1.05);
}

.feature-card img {
    width: 100px;
    height: 100px;
    object-fit: cover;
    margin-bottom: 1rem;
}

.content {
    padding: 2rem;
    background: var(--secondary-color);
    color: var(--primary-color);
}

.content h2 {
    font-family: var(--font-title);
    font-size: 2rem;
    margin-bottom: 1rem;
}

.content pre {
    background: var(--gray-light);
    padding: 1rem;
    border-radius: 5px;
    overflow-x: auto;
}

.content code {
    font-family: 'Courier New', Courier, monospace;
    color: var(--accent-color-green);
}

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

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