body {
    font-family: Arial, sans-serif;
    background-color: #f4f7f6;
    margin: 0;
    padding: 0;
    color: #333;
}
.container {
    width: 90%;
    max-width: 1200px;
    margin: 20px auto;
    padding: 20px;
    background-color: #fff;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
    border-radius: 8px;
}
header {
    background-color: #0056b3;
    color: white;
    padding: 15px 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
header h1 {
    margin: 0;
    font-size: 24px;
}
header nav a {
    color: white;
    text-decoration: none;
    margin-left: 20px;
    font-weight: bold;
}
header nav a:hover {
    text-decoration: underline;
}
h2 {
    color: #0056b3;
    border-bottom: 2px solid #f0f0f0;
    padding-bottom: 10px;
}
table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
}
table, th, td {
    border: 1px solid #ddd;
}
th, td {
    padding: 12px;
    text-align: left;
}
th {
    background-color: #f2f2f2;
    font-weight: bold;
}
tr:nth-child(even) {
    background-color: #f9f9f9;
}
.form-group {
    margin-bottom: 15px;
}
.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
}
.form-group input, .form-group select {
    width: 100%;
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
    box-sizing: border-box;
}
.btn {
    background-color: #0056b3;
    color: white;
    padding: 10px 20px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
    text-decoration: none;
    display: inline-block;
}
.btn:hover {
    background-color: #004494;
}
.btn-danger {
    background-color: #dc3545;
}
.btn-danger:hover {
    background-color: #c82333;
}
.login-container {
    width: 350px;
    margin: 100px auto;
    padding: 30px;
    border: 1px solid #ddd;
    border-radius: 8px;
    background-color: #fff;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
}
.error {
    color: red;
    margin-bottom: 15px;
}