#tts-button {
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 100;
    background-color: #4051b5; /* Indigo, matching the theme */
    color: white;
    border: none;
    border-radius: 24px;
    padding: 10px 20px;
    font-size: 16px;
    cursor: pointer;
    box-shadow: 0 2px 5px rgba(0,0,0,0.3);
    display: flex;
    align-items: center;
    gap: 8px;
    transition: background-color 0.3s, transform 0.2s;
}

#tts-button:hover {
    background-color: #303f9f;
    transform: translateY(-2px);
}

#tts-button:active {
    transform: translateY(0);
}

.tts-icon {
    font-size: 20px;
}

.tts-playing {
    background-color: #e91e63; /* Pink for active state */
}

.tts-playing:hover {
    background-color: #c2185b;
}

@media (max-width: 768px) {
    #tts-button {
        bottom: 70px; /* Avoid covering bottom navigation on mobile if any */
        right: 10px;
        padding: 8px 16px;
        font-size: 14px;
    }
}