* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
    padding: 20px;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    background-color: #fff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

h1 {
    text-align: center;
    margin-bottom: 20px;
    color: #2c3e50;
}

h2 {
    margin: 20px 0;
    color: #2c3e50;
}

.control-panel {
    margin-bottom: 30px;
}

.session-controls, .participant-controls {
    display: flex;
    gap: 10px;
    margin-bottom: 15px;
    align-items: center;
}

.select-wrapper {
    flex-grow: 1;
}

select, input {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 16px;
}

.btn {
    padding: 10px 15px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
    font-weight: bold;
    transition: background-color 0.3s;
}

.primary {
    background-color: #3498db;
    color: white;
}

.primary:hover {
    background-color: #2980b9;
}

.success {
    background-color: #2ecc71;
    color: white;
}

.success:hover {
    background-color: #27ae60;
}

.danger {
    background-color: #e74c3c;
    color: white;
}

.danger:hover {
    background-color: #c0392b;
}

.warning {
    background-color: #f39c12;
    color: white;
}

.warning:hover {
    background-color: #d35400;
}

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

th, td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid #ddd;
}

th {
    background-color: #f2f2f2;
    font-weight: bold;
}

tr:hover {
    background-color: #f9f9f9;
}

.action-buttons {
    display: flex;
    gap: 5px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .session-controls, .participant-controls {
        flex-direction: column;
    }
    
    .btn, select, input {
        width: 100%;
    }
    
    table {
        display: block;
        overflow-x: auto;
    }
    
    th, td {
        min-width: 100px;
    }
}