body {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    font-family: 'Arial', sans-serif;
    color: #333;
}

.card {
    border: none;
    border-radius: 15px;
}

.card-header {
    border-radius: 15px 15px 0 0;
}

.message {
    margin-bottom: 10px;
    padding: 10px;
    border-radius: 10px;
}

.sent {
    background-color: #d4edda;
    text-align: right;
}

.received {
    background-color: #f8d7da;
    text-align: left;
}

.list-group-item a {
    color: #007bff;
}

.list-group-item a:hover {
    color: #0056b3