body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
}

.sidebar {
    width: 250px;
    background-color: #333;
    position: fixed;
    top: 0;
    left: 0;
    height: 100%;
    padding-top: 20px;
}

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

.sidebar ul li {
    padding: 15px;
}

.sidebar ul li a {
    color: #fff;
    text-decoration: none;
    display: block;
}

.sidebar ul li a:hover {
    background-color: #575757;
}

.main-content {
    margin-left: 250px;
    padding: 20px;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 20px;
}

table th, table td {
    padding: 10px;
    border: 1px solid #ddd;
    text-align: left;
}

form {
    max-width: 600px;
    margin: 20px auto;
    padding: 20px;
    background-color: #fff;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    border-radius: 5px;
}

form label {
    display: block;
    margin-bottom: 5px;
}

form input, form select, form textarea {
    width: 100%;
    padding: 10px;
    margin-bottom: 10px;
    border: 1px solid #ddd;
    border-radius: 3px;
}

form button {
    width: 100%;
    padding: 10px;
    background-color: #333;
    color: #fff;
    border: none;
    border-radius: 3px;
    cursor: pointer;
}

form button:hover {
    background-color: #575757;
}

.success {
    color: green;
    text-align: center;
}

@media (max-width: 768px) {
    .sidebar {
        width: 100%;
        height: auto;
        position: relative;
    }
    .sidebar ul {
        display: flex;
        flex-direction: row;
    }
    .sidebar ul li {
        padding: 10px;
        flex: 1;
    }
    .main-content {
        margin-left: 0;
    }
}

.login-container {
    max-width: 300px;
    margin: 100px auto;
    padding: 20px;
    background-color: #fff;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    border-radius: 5px;
}

.login-container h2 {
    margin-bottom: 20px;
    text-align: center;
}

.login-container input {
    width: 100%;
    padding: 10px;
    margin-bottom: 10px;
    border: 1px solid #ddd;
    border-radius: 3px;
}

.login-container button {
    width: 100%;
    padding: 10px;
    background-color: #333;
    color: #fff;
    border: none;
    border-radius: 3px;
    cursor: pointer;
}

.login-container button:hover {
    background-color: #575757;
}

.error {
    color: red;
    text-align: center;
}