body.dark {
    background-color: #111;
    color: #eee;
    font-family: 'Segoe UI', sans-serif;
    margin: 0;
    padding: 0;
}

header {
    text-align: center;
    padding: 30px 15px;
    background: #1f1f1f;
    border-bottom: 2px solid #444;
}

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

header p {
    margin: 10px 0 0;
    font-size: 1.1rem;
    color: #aaa;
}

.grid {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 20px;
    padding: 30px;
}

.card {
    background: #222;
    border: 1px solid #333;
    border-radius: 8px;
    width: 300px;
    padding: 20px;
    text-align: center;
    transition: transform 0.2s ease;
}

.card:hover {
    transform: scale(1.03);
    border-color: #555;
}

.card img {
    max-width: 100%;
    height: 180px;
    object-fit: cover;
    border-radius: 4px;
}

.card h2 {
    margin: 15px 0 10px;
    font-size: 1.3rem;
}

.card p {
    color: #bbb;
    font-size: 0.95rem;
}

.btn {
    display: inline-block;
    margin-top: 10px;
    padding: 10px 18px;
    background: #3a8edb;
    color: white;
    text-decoration: none;
    border-radius: 5px;
    transition: background 0.2s ease;
}

.btn:hover {
    background: #2a76bb;
}

footer {
    text-align: center;
    padding: 20px;
    font-size: 0.9rem;
    color: #888;
    background: #1c1c1c;
}

.cs-detail {
    padding: 30px;
    max-width: 800px;
    margin: auto;
    color: #ccc;
}

.cs-detail img {
    width: 100%;
    max-height: 300px;
    object-fit: cover;
    margin-bottom: 20px;
    border-radius: 5px;
}

.video iframe {
    width: 100%;
    height: 400px;
    margin: 20px 0;
}

.login-box {
    max-width: 400px;
    margin: 100px auto;
    padding: 30px;
    background: #222;
    border-radius: 8px;
    text-align: center;
    color: #eee;
}

.login-box input {
    display: block;
    width: 100%;
    margin: 10px 0;
    padding: 10px;
    border: none;
    border-radius: 5px;
}

.login-box .error {
    color: red;
    font-size: 0.9rem;
}