body {
    display: flex;
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
}
#navbar {
    position: fixed;
    left: 0;
    top: 0;
    width: 250px;
    height: 100%;
    background-color: #f4f4f4;
    border-right: 2px solid #ccc;
    padding: 20px;
    overflow-y: auto;
  }
#navbar header {
    font-size: 1.5em;
    font-weight: bold;
    margin-bottom: 20px;
}
.nav-link {
    display: block;
    padding: 10px 0;
    color: #333;
    text-decoration: none;
}
.nav-link:hover {
    color: #007bff;
}
#main-doc {
    margin-left: 260px;
    padding: 20px;
    width: calc(100% - 260px);
    display: flex;
    flex-direction: column;
}
.main-section {
    width: 80%;
    margin-bottom: 20px;
    margin-left: 20px;
    padding: 20px;
    border: 1px solid #ddd;
    border-radius: 8px;
    background-color: #fff;
    box-shadow: 2px 2px 10px rgba(0, 0, 0, 0.1);
}
.main-section header {
    font-size: 1.4em;
    font-weight: bold;
    margin-bottom: 10px;
}
@media (max-width: 768px) {
    #navbar {
        width: 100%;
        position: relative;
    }
    #main-doc {
        margin-left: 0;
    }
}