body {
    font-family: Arial, sans-serif;
    background: #f4f4f4;
    margin: 0;
    padding: 20px;
}
.container {
    max-width: 1200px;
    margin: auto;
    background: #fff;
    padding: 20px;
    border-radius: 8px;
}
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid #ddd;
    padding-bottom: 10px;
}
nav a {
    margin-left: 15px;
    text-decoration: none;
    color: #007bff;
}
nav a:hover {
    text-decoration: underline;
}
table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
}
table th, table td {
    border: 1px solid #ddd;
    padding: 8px;
    text-align: left;
}
table th {
    background: #007bff;
    color: white;
}
form label {
    display: block;
    margin-top: 10px;
    font-weight: bold;
}
form input, form select, form textarea {
    width: 100%;
    padding: 8px;
    margin-top: 5px;
    box-sizing: border-box;
}
form button {
    margin-top: 15px;
    padding: 10px 20px;
    background: #007bff;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}
.error {
    background: #ffcccc;
    padding: 10px;
    border: 1px solid #ff0000;
    margin-bottom: 10px;
}
.login-container {
    max-width: 400px;
    margin: 100px auto;
    background: #fff;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
}