.tta-btn {
    background: linear-gradient(270deg, white, blue, green, purple);
    background-size: 400% 400%;
    color: #fff;
    padding: 10px 20px;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    font-size: 16px;
    animation: gradientShift 6s ease infinite;
}

@keyframes gradientShift {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

#tta-text, #tta-language, #tta-voice, #tta-voice-type {
    width: 100%;
    padding: 10px;
    margin-bottom: 10px;
    font-size: 16px;
}