.tts-floating-btn {
    position: fixed;
    right: 20px;
    bottom: 20px;
    width: 50px;
    height: 50px;
    border: none;
    border-radius: 50%;
    background-color: #1a3c6e;
    color: #ffffff;
    font-size: 22px;
    line-height: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    z-index: 9999;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.25);
    transition: transform 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease;
}

.tts-floating-btn:hover {
    background-color: #214b89;
    transform: translateY(-2px);
    box-shadow: 0 10px 22px rgba(0, 0, 0, 0.3);
}

.tts-floating-btn:focus-visible {
    outline: 2px solid #ffffff;
    outline-offset: 2px;
}

.tts-floating-btn.speaking {
    animation: ttsPulse 1.3s ease-in-out infinite;
}

@keyframes ttsPulse {
    0% {
        box-shadow: 0 0 0 0 rgba(26, 60, 110, 0.5), 0 8px 20px rgba(0, 0, 0, 0.25);
    }

    70% {
        box-shadow: 0 0 0 12px rgba(26, 60, 110, 0), 0 8px 20px rgba(0, 0, 0, 0.25);
    }

    100% {
        box-shadow: 0 0 0 0 rgba(26, 60, 110, 0), 0 8px 20px rgba(0, 0, 0, 0.25);
    }
}