body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    background-color: #f0f2f5;
    color: #2c3e50;
    margin: 0;
    padding: 20px;
}

header {
    text-align: center;
    background-color: #1a252f;
    color: #ffffff;
    padding: 30px 15px;
    border-radius: 6px;
    margin-bottom: 25px;
}

header h1 {
    margin: 0 0 8px 0;
    font-size: 2rem;
}

header h2 {
    font-size: 1.1rem;
    font-weight: 300;
    color: #3498db;
    margin: 0;
}

main {
    max-width: 800px;
    margin: 0 auto;
    background: #ffffff;
    padding: 35px;
    border-radius: 6px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.05);
}

section {
    margin-bottom: 35px;
}

h3 {
    font-size: 1.3rem;
    color: #2c3e50;
    border-bottom: 3px solid #3498db;
    padding-bottom: 6px;
    margin-top: 0;
}

code {
    background-color: #f8f9fa;
    color: #e74c3c;
    padding: 2px 6px;
    border-radius: 4px;
    font-family: Consolas, Monaco, monospace;
    font-size: 0.95rem;
}

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

iframe {
    width: 100%;
    max-width: 560px;
    height: 315px;
    border: none;
    border-radius: 6px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}

footer {
    text-align: center;
    margin-top: 40px;
    font-size: 0.85rem;
    color: #7f8c8d;
}