body {
    margin: 0;
    font-family: sans-serif;
    display: flex;
    flex-direction: column;
    align-items: center;
    background-color: #f5f5f5;
}

#call-container {
    width: 90vw;
    max-width: 1000px;
    height: 600px;
    background: #000;
    margin-top: 20px;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

.controls {
    margin: 20px;
}

.btn {
    padding: 12px 24px;
    font-size: 16px;
    cursor: pointer;
    border: none;
    border-radius: 6px;
    background-color: #007bff;
    color: white;
}

.btn-danger {
    background-color: #dc3545;
}