HelpButton.uss

.help-button {
    width: 16px;
    height: 16px;
    padding: 0 0 0 0;
    margin: 0 0 0 0;
    background-image: none;
    background-color: var(--unity-colors-window-background);
    border-width: 0;
    border-radius: 0;
}

.help-button:hover {
    background-color: var(--unity-colors-button-background-hover);
}

.help-button:active {
    background-color: var(--unity-colors-button-background-hover_pressed);
}

.help-button__image {
    background-image: none;
}