body {
    font-family: Arial, sans-serif;
    background-color: #f0f0f0;
    color: #333;
    display: flex;
    flex-direction: column;
    align-items: center;
    margin: 0;
    padding: 20px;
}

h1 {
    color: #0056b3;
}

.audio-container {
    display: flex;
    gap: 20px;
    margin: 20px 0;
}

.audio-container div {
    background-color: #fff;
    border: 1px solid #ccc;
    padding: 15px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

audio {
    width: 300px;
}

.controls button {
    padding: 10px 20px;
    font-size: 16px;
    cursor: pointer;
    border: none;
    border-radius: 5px;
    margin: 5px;
    transition: background-color 0.3s;
}

#startCall {
    background-color: #28a745;
    color: white;
}

#startCall:disabled {
    background-color: #a5d6a7;
    cursor: not-allowed;
}

#hangUp {
    background-color: #dc3545;
    color: white;
}

#hangUp:disabled {
    background-color: #f8d7da;
    cursor: not-allowed;
}