body {
    background-color: #f5f7fa;
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 20px;
}

.container {
    max-width: 850px;
    margin: 0 auto;
    background: #ffffff;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 0 12px #ddd;
}

h1 {
    text-align: center;
    color: #222;
}

.intro {
    text-align: center;
    color: #666;
    margin-bottom: 35px;
}

.step {
    margin: 30px 0;
    padding-bottom: 20px;
    border-bottom: 1px solid #eee;
}

.step h2 {
    font-size: 20px;
    color: #2c3e50;
    margin-bottom: 8px;
}

.step p {
    color: #444;
}

.screenshot {
    width: 100%;
    max-width: 700px;
    border: 1px solid #ccc;
    border-radius: 6px;
    margin-top: 10px;
}

.video-box {
    margin-top: 40px;
    text-align: center;
}

.video-box iframe {
    width: 600px;
    height: 350px;
    max-width: 100%;
}