body {
    font-family: Arial, sans-serif;
    background: #1e1e1e;
    color: #ccc;
    margin: 0;
    padding: 0;
    line-height: 1.6;
}

header {
    background: #111;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    position: relative;
}

.logo {
    position: absolute;
    left: 20px;
    max-width: 70px;
    height: auto;
}

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

.header-text h1 {
    margin: 0;
    color: #fff;
    font-size: 2rem;
}

.header-text p {
    margin: 5px 0 0 0;
    color: #ccc;
}

main {
    max-width: 1000px;
    margin: 20px auto;
    padding: 0 20px;
}

h1, h2, h3 {
    color: #fff;
}

section {
    background: #2b2b2b;
    padding: 20px;
    margin-bottom: 20px;
    border-radius: 8px;
}

video {
    width: 100%;
    height: auto;
    max-height: 600px;
    margin: 10px 0;
    border-radius: 6px;
    border: 1px solid #444;
    display: block;
}

nav {
    text-align: center;
    margin: 20px 0;
}

nav a {
    display: inline-block;
    padding: 10px 20px;
    margin: 0 8px;
    border: 2px solid #4da6ff;
    border-radius: 6px;
    color: #4da6ff;
    text-decoration: none;
    font-weight: bold;
    transition: background 0.2s, color 0.2s;
}

nav a:hover {
    background: #4da6ff; 
    color: #fff;
}

.link {
    color: #1e90ff;
    text-decoration: none;
    position: relative;
    transition: color 0.3s ease;
}

.link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    display: block;
    right: 0;
    background: #1e90ff;
    transition: width 0.3s ease;
}

.link:hover {
    color: #63b3ed;
}

.link:hover::after {
    width: 100%;
    left: 0;
    background: #63b3ed;
}

pre {
    border-radius: 6px;
    overflow-x: auto;
    padding: 15px;
}

@media (max-width: 768px) {
    main { padding: 0 10px; }
    section { padding: 15px; }
    video { max-height: 400px; }
}

@media (max-width: 480px) {
    header, nav a { padding: 15px; }
    video { max-height: 300px; }
    .logo { max-width: 50px; }
    .header-text h1 { font-size: 1.5rem; }
}