body, html {
    margin: 0;
    padding: 0;
    font-family: Arial, sans-serif;
    background-color: #f0f0f0;
}

.container {
    width: 80%;
    margin: auto;
    background: #fff;
    box-shadow: 0px 0px 10px rgba(0,0,0,0.1);
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 20px;
}

h1 {
    color: #333;
}

.main-content {
    display: flex;
}

.nav-frame {
    width: 30%;
    height: 800px;
    border: 1px solid #ccc;
}

.content-frame {
    width: 65%;
    height: 800px;
    border: 1px solid #ccc;
    margin-left: 20px;
}