.audio-btn {
    --audio-btn-size: 64px;
    background: #000;
    color: #fff;
    border-radius: 50%;
    width: var(--audio-btn-size);
    height: var(--audio-btn-size);
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0;
    line-height: 1;
    transition: transform 0.15s ease;
}

.audio-btn:hover {
    transform: scale(1.03);
}

.audio-btn:focus-visible {
    outline: 2px solid #fff;
    outline-offset: 2px;
}

.audio-btn:disabled {
    cursor: default;
}

.audio-btn-icon {
    width: 62%;
    height: 62%;
    background-repeat: no-repeat;
    background-size: contain;
    background-position: center;
    background-image: var(--audio-btn-icon-image, url("icons/mic-256.svg"));
}

.audio-btn.is-playing .audio-btn-icon {
    background-image: url("icons/stop-256.svg");
}