body {
    font-family: 'Roboto', sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f0f2f5;
    display: flex;
    flex-direction: column;
    height: 100vh;
}

.top-nav {
    background-color: #007bff;
    color: white;
    padding: 1rem;
    text-align: center;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.container {
    display: flex;
    flex: 1;
}

.sidebar {
    width: 250px;
    background-color: #343a40;
    color: white;
    padding: 1rem;
    box-shadow: 2px 0 5px rgba(0,0,0,0.1);
}

.sidebar ul {
    list-style-type: none;
    padding: 0;
}

.sidebar ul li {
    margin: 1rem 0;
}

.sidebar ul li a {
    color: white;
    text-decoration: none;
    font-size: 1.1rem;
    display: block;
    padding: 0.5rem;
    border-radius: 4px;
}

.sidebar ul li a:hover {
    background-color: #495057;
}

.main-content {
    flex-grow: 1;
    padding: 2rem;
    background-color: white;
    border-top: 1px solid #e0e0e0;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
    overflow-y: auto;
}