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

body {
    font-family: Arial, Helvetica, sans-serif;
    background-color: grey;
    color: #333;
    line-height: 1.6;
}

header {
    text-align: center;
    padding: 40px 20px;
    color: white;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

header p {
    font-size: 1.1rem;
    opacity: 0.9;
}

.container {
    width: 90%;
    max-width: 1100px;
    margin: 30px auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
}

.card {
    background: white;
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 25px rgba(0, 0, 0, 0.25);
}

.card h2 {
    margin-bottom: 15px;
    color: #1e3c72;
}

.card p {
    margin-bottom: 10px;
}

.card ul {
    padding-left: 20px;
}

.card ul li {
    margin-bottom: 8px;
}

pre {
    background: #1e1e1e;
    color: #00ff88;
    padding: 15px;
    border-radius: 8px;
    overflow-x: auto;
    margin: 15px 0;
    font-size: 0.9rem;
}

code {
    font-family: "Courier New", monospace;
}

button {
    background: #1e3c72;
    color: white;
    border: none;
    padding: 10px 18px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.95rem;
    transition: 0.3s ease, transform 0.2s ease;
}

button:hover {
    background: #16325c;
    transform: scale(1.05);
}

@media (max-width: 600px) {
    header h1 {
        font-size: 2rem;
    }
}