:root {
    --primary-color: #000000;
    --secondary-color: #1E90FF;
    --accent-color: #FFD700;
    --neon-green: #39FF14;
    --electric-purple: #9400D3;
    --gradient-start: #1E90FF;
    --gradient-end: #000000;
}

body {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: white;
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 20px;
    overflow-x: hidden;
}

h1, h2, h3, h4 {
    font-weight: bold;
    color: var(--secondary-color);
    margin-top: 30px;
    margin-bottom: 15px;
}

p {
    margin-bottom: 20px;
    text-align: justify;
}

pre {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid var(--neon-green);
    border-radius: 8px;
    padding: 15px;
    overflow-x: auto;
    font-size: 14px;
    margin-bottom: 20px;
}

code {
    color: var(--electric-purple);
    font-family: 'Courier New', monospace;
}

.line {
    width: 100px;
    height: 2px;
    background: linear-gradient(to right, var(--secondary-color), var(--accent-color));
    position: relative;
    animation: extend 2s infinite alternate;
    margin: 20px auto;
}

@keyframes extend {
    from {
        width: 50px;
    }
    to {
        width: 150px;
    }
}

button {
    background: none;
    border: 2px solid var(--secondary-color);
    color: white;
    padding: 10px 20px;
    transition: all 0.3s ease;
    cursor: pointer;
    border-radius: 5px;
}

button:hover {
    background: var(--secondary-color);
    transform: scale(1.1);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.5);
}

.background {
    width: 100%;
    height: 200px;
    background: radial-gradient(circle, var(--secondary-color), var(--primary-color));
    margin-bottom: 30px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
}

.card {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--neon-green);
    border-radius: 10px;
    padding: 20px;
    text-align: center;
    transition: transform 0.3s ease;
}

.card:hover {
    transform: translateY(-10px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.3);
}

.card img {
    width: 100%;
    height: auto;
    border-radius: 8px;
    margin-bottom: 15px;
}

@media (max-width: 768px) {
    body {
        font-size: 14px;
    }

    .line {
        width: 50px;
    }

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