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

.container {
    max-width: 600px;
    margin: 20px auto;
    padding: 20px;
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

h1, h2 {
    text-align: center;
}

form {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

input, button {
    padding: 10px;
    font-size: 16px;
    border: 1px solid #ccc;
    border-radius: 4px;
}

button {
    background-color: #007BFF;
    color: white;
    cursor: pointer;
}

button:hover {
    background-color: #0056b3;
}

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

table, th, td {
    border: 1px solid #ddd;
}

th, td {
    padding: 8px;
    text-align: center;
}

a {
    display: block;
    text-align: center;
    margin-top: 20px;
    text-decoration: none;
    color: #007BFF;
}

a:hover {
    text-decoration: underline;
}

.error-message {
    background-color: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
    border-radius: 4px;
    padding: 15px;
    margin: 20px 0;
    text-align: center;
}

.error-message p {
    margin: 0 0 10px 0;
}

.error-message p:last-child {
    margin-bottom: 0;
}

.participant-list {
    margin-top: 30px;
}

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

.participant-list li {
    margin-bottom: 10px;
}

.participant-list a {
    display: block;
    padding: 12px;
    background-color: #f8f9fa;
    border: 1px solid #dee2e6;
    border-radius: 4px;
    text-decoration: none;
    color: #495057;
    transition: background-color 0.2s, color 0.2s;
}

.participant-list a:hover {
    background-color: #007BFF;
    color: white;
    text-decoration: none;
}

.class-section {
    margin-bottom: 20px;
}

.class-header {
    font-size: 18px;
    font-weight: bold;
    color: #333;
    margin-bottom: 10px;
    padding: 8px;
    background-color: #e9ecef;
    border-radius: 4px;
}

.class-participants {
    list-style-type: none;
    padding: 0;
    margin: 0;
}

.class-participants li {
    margin-bottom: 8px;
}

.participant-link {
    display: block;
    padding: 10px;
    background-color: #f8f9fa;
    border: 1px solid #dee2e6;
    border-radius: 4px;
    text-decoration: none;
    color: #495057;
    transition: background-color 0.2s, color 0.2s;
}

.participant-link:hover {
    background-color: #007BFF;
    color: white;
    text-decoration: none;
}